Power Up Your Open WebUI with Azure AI Speech: Quick STT & TTS Integration
Introduction Ever found yourself wishing your web interface could really talk and listen back to you? With a few clicks (and a bit of code), you can turn your plain Open WebUI into a full-on voice assistant. In this post, you’ll see how to spin up an Azure Speech resource, hook it into your frontend, and watch as user speech transforms into text and your app’s responses leap off the screen in a human-like voice. By the end of this guide, you’ll have a voice-enabled web UI that actually converses with users, opening the door to hands-free controls, better accessibility, and a genuinely richer user experience. Ready to make your web app speak? Let’s dive in. Why Azure AI Speech? We use Azure AI Speech service in Open Web UI to enable voice interactions directly within web applications. This allows users to: Speak commands or input instead of typing, making the interface more accessible and user-friendly. Hear responses or information read aloud, which improves usability for people with visual impairments or those who prefer audio. Provide a more natural and hands-free experience especially on devices like smartphones or tablets. In short, integrating Azure AI Speech service into Open Web UI helps make web apps smarter, more interactive, and easier to use by adding speech recognition and voice output features. If you haven’t hosted Open WebUI already, follow my other step-by-step guide to host Ollama WebUI on Azure. Proceed to the next step if you have Open WebUI deployed already. Learn More about OpenWeb UI here. Deploy Azure AI Speech service in Azure. Navigate to the Azure Portal and search for Azure AI Speech on the Azure portal search bar. Create a new Speech Service by filling up the fields in the resource creation page. Click on “Create” to finalize the setup. After the resource has been deployed, click on “View resource” button and you should be redirected to the Azure AI Speech service page. The page should display the API Keys and Endpoints for Azure AI Speech services, which you can use in Open Web UI. Settings things up in Open Web UI Speech to Text settings (STT) Head to the Open Web UI Admin page > Settings > Audio. Paste the API Key obtained from the Azure AI Speech service page into the API key field below. Unless you use different Azure Region, or want to change the default configurations for the STT settings, leave all settings to blank. Text to Speech settings (TTS) Now, let's proceed with configuring the TTS Settings on OpenWeb UI by toggling the TTS Engine to Azure AI Speech option. Again, paste the API Key obtained from Azure AI Speech service page and leave all settings to blank. You can change the TTS Voice from the dropdown selection in the TTS settings as depicted in the image below: Click Save to reflect the change. Expected Result Now, let’s test if everything works well. Open a new chat / temporary chat on Open Web UI and click on the Call / Record button. The STT Engine (Azure AI Speech) should identify your voice and provide a response based on the voice input. To test the TTS feature, click on the Read Aloud (Speaker Icon) under any response from Open Web UI. The TTS Engine should reflect Azure AI Speech service! Conclusion And that’s a wrap! You’ve just given your Open WebUI the gift of capturing user speech, turning it into text, and then talking right back with Azure’s neural voices. Along the way you saw how easy it is to spin up a Speech resource in the Azure portal, wire up real-time transcription in the browser, and pipe responses through the TTS engine. From here, it’s all about experimentation. Try swapping in different neural voices or dialing in new languages. Tweak how you start and stop listening, play with silence detection, or add custom pronunciation tweaks for those tricky product names. Before you know it, your interface will feel less like a web page and more like a conversation partner.Foundry IQ: Give Your AI Agents a Knowledge Upgrade
If you’re learning to build AI agents, you’ve probably hit a familiar wall: your agent can generate text, but it doesn’t actually know anything about your data. It can’t look up your documents, search across your files, or pull facts from multiple sources to answer a real question. That’s the gap Foundry IQ fills. It gives your AI agents structured access to knowledge, so they can retrieve, reason over, and synthesize information from real data sources instead of relying on what’s baked into the model. Why Should You Care? As a student or early-career developer, understanding how AI systems work with external knowledge is one of the most valuable skills you can build right now. Retrieval-Augmented Generation (RAG), knowledge bases, and multi-source querying are at the core of every production AI application, from customer support bots to research assistants to enterprise copilots. Foundry IQ gives you a hands-on way to learn these patterns without having to build all the plumbing yourself. You define knowledge bases, connect data sources, and let your agents query them. The concepts you learn here transfer directly to real-world AI engineering roles. What is Foundry IQ? Foundry IQ is a service within Azure AI Foundry that lets you create knowledge bases, collections of connected data sources that your AI agents can query through a single endpoint. Instead of writing custom retrieval logic for every app you build, you: Define knowledge sources — connect documents, data stores, or web content (SharePoint, Azure Blob Storage, Azure AI Search, Fabric OneLake, and more). Organize them into a knowledge base — group multiple sources behind one queryable endpoint. Query from your agent — your AI agent calls the knowledge base to get the context it needs before generating a response. This approach means the knowledge layer is reusable. Build it once, and any agent or app in your project can tap into it. The IQ Series: A Three-Part Learning Path The IQ Series is a set of three weekly episodes that walk you through Foundry IQ from concept to code. Each episode includes a tech talk, visual doodle summaries, and a companion cookbook with sample code you can run yourself. 👉 Get started: https://aka.ms/iq-series Episode 1: Unlocking Knowledge for Your Agents (March 18, 2026) Start here. This episode introduces the core architecture of Foundry IQ and explains how AI agents interact with knowledge. You’ll learn what knowledge bases are, why they matter, and how the key components fit together. What you’ll learn: The difference between model knowledge and retrieved knowledge How Foundry IQ structures the retrieval layer The building blocks: knowledge sources, knowledge bases, and agent queries Episode 2: Building the Data Pipeline with Knowledge Sources (March 25, 2026) This episode goes deeper into knowledge sources, the connectors that bring data into Foundry IQ. You’ll see how different content types flow into the system and how to wire up sources from services you may already be using. What you’ll learn: How to connect sources like Azure Blob Storage, Azure AI Search, SharePoint, Fabric OneLake, and the web How content is ingested and indexed for retrieval Patterns for combining multiple source types Episode 3: Querying Multi-Source Knowledge Bases (April 1, 2026) The final episode shows you how to bring it all together. You’ll learn how agents query across multiple knowledge sources through a single knowledge base endpoint and how to synthesize answers from diverse data. What you’ll learn: How to query a knowledge base from your agent code How retrieval works across multiple connected sources Techniques for synthesizing information to answer complex questions Get Hands-On with the Cookbooks Every episode comes with a companion cookbook in the GitHub repo, complete with sample code you can clone, run, and modify. This is the fastest way to go from watching to building. 👉 Explore the repo: https://aka.ms/iq-series Inside you’ll find: Episode links — watch the tech talks and doodle recaps Cookbooks — step-by-step code samples for each episode Documentation links — official Foundry IQ docs and additional learning resources What to Build Next Once you’ve worked through the series, try applying what you’ve learned: Study assistant — connect your course materials as knowledge sources and build an agent that can answer questions across all your notes and readings. Project documentation bot — index your team’s project docs and READMEs into a knowledge base so everyone can query them naturally. Research synthesizer — connect multiple data sources (papers, web content, datasets) and build an agent that can cross-reference and summarize findings. Start Learning The IQ Series is designed to take you from zero to building knowledge-driven AI agents. Watch the episodes, run the cookbooks, and start experimenting with your own knowledge bases. 👉 https://aka.ms/iq-seriesIntegrating Microsoft Foundry with OpenClaw: Step by Step Model Configuration
Step 1: Deploying Models on Microsoft Foundry Let us kick things off in the Azure portal. To get our OpenClaw agent thinking like a genius, we need to deploy our models in Microsoft Foundry. For this guide, we are going to focus on deploying gpt-5.2-codex on Microsoft Foundry with OpenClaw. Navigate to your AI Hub, head over to the model catalog, choose the model you wish to use with OpenClaw and hit deploy. Once your deployment is successful, head to the endpoints section. Important: Grab your Endpoint URL and your API Keys right now and save them in a secure note. We will need these exact values to connect OpenClaw in a few minutes. Step 2: Installing and Initializing OpenClaw Next up, we need to get OpenClaw running on your machine. Open up your terminal and run the official installation script: curl -fsSL https://openclaw.ai/install.sh | bash The wizard will walk you through a few prompts. Here is exactly how to answer them to link up with our Azure setup: First Page (Model Selection): Choose "Skip for now". Second Page (Provider): Select azure-openai-responses. Model Selection: Select gpt-5.2-codex , For now only the models listed (hosted on Microsoft Foundry) in the picture below are available to be used with OpenClaw. Follow the rest of the standard prompts to finish the initial setup. Step 3: Editing the OpenClaw Configuration File Now for the fun part. We need to manually configure OpenClaw to talk to Microsoft Foundry. Open your configuration file located at ~/.openclaw/openclaw.json in your favorite text editor. Replace the contents of the models and agents sections with the following code block: { "models": { "providers": { "azure-openai-responses": { "baseUrl": "https://<YOUR_RESOURCE_NAME>.openai.azure.com/openai/v1", "apiKey": "<YOUR_AZURE_OPENAI_API_KEY>", "api": "openai-responses", "authHeader": false, "headers": { "api-key": "<YOUR_AZURE_OPENAI_API_KEY>" }, "models": [ { "id": "gpt-5.2-codex", "name": "GPT-5.2-Codex (Azure)", "reasoning": true, "input": ["text", "image"], "cost": { "input": 0, "output": 0, "cacheRead": 0, "cacheWrite": 0 }, "contextWindow": 400000, "maxTokens": 16384, "compat": { "supportsStore": false } }, { "id": "gpt-5.2", "name": "GPT-5.2 (Azure)", "reasoning": false, "input": ["text", "image"], "cost": { "input": 0, "output": 0, "cacheRead": 0, "cacheWrite": 0 }, "contextWindow": 272000, "maxTokens": 16384, "compat": { "supportsStore": false } } ] } } }, "agents": { "defaults": { "model": { "primary": "azure-openai-responses/gpt-5.2-codex" }, "models": { "azure-openai-responses/gpt-5.2-codex": {} }, "workspace": "/home/<USERNAME>/.openclaw/workspace", "compaction": { "mode": "safeguard" }, "maxConcurrent": 4, "subagents": { "maxConcurrent": 8 } } } } You will notice a few placeholders in that JSON. Here is exactly what you need to swap out: Placeholder Variable What It Is Where to Find It <YOUR_RESOURCE_NAME> The unique name of your Azure OpenAI resource. Found in your Azure Portal under the Azure OpenAI resource overview. <YOUR_AZURE_OPENAI_API_KEY> The secret key required to authenticate your requests. Found in Microsoft Foundry under your project endpoints or Azure Portal keys section. <USERNAME> Your local computer's user profile name. Open your terminal and type whoami to find this. Step 4: Restart the Gateway After saving the configuration file, you must restart the OpenClaw gateway for the new Foundry settings to take effect. Run this simple command: openclaw gateway restart Configuration Notes & Deep Dive If you are curious about why we configured the JSON that way, here is a quick breakdown of the technical details. Authentication Differences Azure OpenAI uses the api-key HTTP header for authentication. This is entirely different from the standard OpenAI Authorization: Bearer header. Our configuration file addresses this in two ways: Setting "authHeader": false completely disables the default Bearer header. Adding "headers": { "api-key": "<key>" } forces OpenClaw to send the API key via Azure's native header format. Important Note: Your API key must appear in both the apiKey field AND the headers.api-key field within the JSON for this to work correctly. The Base URL Azure OpenAI's v1-compatible endpoint follows this specific format: https://<your_resource_name>.openai.azure.com/openai/v1 The beautiful thing about this v1 endpoint is that it is largely compatible with the standard OpenAI API and does not require you to manually pass an api-version query parameter. Model Compatibility Settings "compat": { "supportsStore": false } disables the store parameter since Azure OpenAI does not currently support it. "reasoning": true enables the thinking mode for GPT-5.2-Codex. This supports low, medium, high, and xhigh levels. "reasoning": false is set for GPT-5.2 because it is a standard, non-reasoning model. Model Specifications & Cost Tracking If you want OpenClaw to accurately track your token usage costs, you can update the cost fields from 0 to the current Azure pricing. Here are the specs and costs for the models we just deployed: Model Specifications Model Context Window Max Output Tokens Image Input Reasoning gpt-5.2-codex 400,000 tokens 16,384 tokens Yes Yes gpt-5.2 272,000 tokens 16,384 tokens Yes No Current Cost (Adjust in JSON) Model Input (per 1M tokens) Output (per 1M tokens) Cached Input (per 1M tokens) gpt-5.2-codex $1.75 $14.00 $0.175 gpt-5.2 $2.00 $8.00 $0.50 Conclusion: And there you have it! You have successfully bridged the gap between the enterprise-grade infrastructure of Microsoft Foundry and the local autonomy of OpenClaw. By following these steps, you are not just running a chatbot; you are running a sophisticated agent capable of reasoning, coding, and executing tasks with the full power of GPT-5.2-codex behind it. The combination of Azure's reliability and OpenClaw's flexibility opens up a world of possibilities. Whether you are building an automated devops assistant, a research agent, or just exploring the bleeding edge of AI, you now have a robust foundation to build upon. Now it is time to let your agent loose on some real tasks. Go forth, experiment with different system prompts, and see what you can build. If you run into any interesting edge cases or come up with a unique configuration, let me know in the comments below. Happy coding!The Hidden Architecture of Nano Architectures
Why does the same prompt, on the same checkpoint, with temperature set to zero, sometimes produce a different answer only when the system is under real load? If you have ever watched token three flip and then watched the whole completion diverge, you already know this is not a product bug. It is a systems fact. Here is the thing. In production, you did not deploy a model. You deployed a runtime that selects an execution plan under constraints. The weights are inside that plan. The behavior is the plan. I’m Hazem Ali — Microsoft AI MVP, Distinguished AI and ML Engineer and Architect, and Founder and CEO of Skytells. I’ve built and led engineering work that turns deep learning research into production systems that survive real-world constraints. I speak at major conferences and technical communities, and I regularly deliver deep technical sessions on enterprise AI and agent architectures. If there’s one thing you’ll notice about me, it’s that I’m drawn to the deepest layers of engineering, the parts most teams only discover when systems are under real pressure. My specialization spans the full AI stack, from deep learning and system design to enterprise architecture and security. A rule I repeat in every serious review is simple. If you cannot explain the runtime, you do not understand the model you deployed. — Hazem Ali This is the next layer after my earlier deep dive on memory, KV cache, paging, and trust boundaries in The Hidden Memory Architecture of LLMs I also break down the memory-and-paging failure modes in When Your LLM Trips the MMU This one goes lower, into the execution that decides which math actually runs. When I Had to Prove It Live I still remember the first time I had to make this concrete in front of a room full of engineers. It was during a technical session I gave, and the question came up in the exact form you’ve probably heard before: Why does the same prompt on the same checkpoint, with temperature set to zero, sometimes produce a different answer only under real load? So I answered it the only way that holds up in a serious engineering room. I didn’t frame it as randomness. I framed it as execution. Not because it sounds cleaner, but because it is the only framing that survives scrutiny: under load, the system is not evaluating the same computation. In production, you don’t deploy weights in isolation. You deploy a runtime that selects an execution plan under constraints. Under load, the constraints change at token cadence: microbatch membership shifts, shapes shift, workspace feasibility tightens, and kernels or algorithms that were legal in the calm regime can become infeasible in the pressured regime. The runtime stays correct by contract, but it executes a different plan. And once the executed plan changes, reduction staging can change. When reduction staging changes, rounding happens at different points. That can move last bits. In decoding, last bits can become different tokens when early logit margins are thin. After the first token flips, divergence is expected because the context is different. That’s what I mean throughout this article when I say: The weights are inside the plan, but the behavior is the plan. What is Happening in Runtime Let’s start with the part most teams skip: the runtime pipeline from admission to a token. A production LLM server is not a function call. It is a control plane. And under real load, it behaves like one. It is not asking “what does the model say.” It is asking “what can I execute right now without breaking my guarantees.” Right now matters. Not in theory, in milliseconds. Because every decode step is a new scheduling event. The system does not commit to a single plan for the entire completion. It keeps re-evaluating feasibility as state shifts. What can I execute at this moment, with the VRAM I still have, on the hardware state I am currently in, while staying inside isolation boundaries and latency targets. That question is not answered once per request. It is answered repeatedly, at token cadence. The queue changes. The batch changes. Memory headroom changes. Cache residency changes. Workspace availability changes. The set of legal kernel and algorithm choices changes with them. And that is the point most people miss. The runtime is not just running your weights. It is continuously selecting an execution plan under constraint. The weights are inside that plan, but behavior lives in the selection. That selection is layered. Admission shapes the effective request. Scheduling forms the batch for this step. Kernel and algorithm choice binds the math that will actually run. Memory residency and allocation decide what is feasible. Isolation rules decide what sharing is allowed. Each layer contributes to the final plan, and the plan is what you are deploying. Admission and shaping Before your prompt ever reaches the model, it gets shaped. Truncation, policy injection, tool schema expansion, routing metadata, tenant tags, prefix reuse decisions, and safety transformations. If you do not know what I mean by effective request, I mean the exact token sequence that the model saw after shaping. That is the only input that matters for reproducibility. Batching and step level scheduling Modern servers do not just batch requests. They batch token steps. In a continuous batching system, token step timing feeds back into batching decisions. A slightly slower step changes who joins the next step. Who joins the next step changes shapes. Shapes change kernels. Kernels change numeric pathways. This is not an opinion. It is why vLLM exists. The PagedAttention paper describes serving as a batching problem where KV cache grows dynamically, wastes memory through fragmentation, and limits batch size. It introduces block level KV management and builds vLLM on top of it as an LLM serving system. Kernel plan selection and library behavior Once shapes are known, the runtime selects kernel variants and library algorithms that are feasible for those shapes and the workspace currently available. This is the part people underestimate. The same operator can have multiple valid implementations. The chosen implementation can change when workspace is tight, when shapes change, or when the engine wants to trade latency for throughput. Memory allocation and residency KV cache, activations, temporary buffers, workspace, graph memory, and communication buffers compete for VRAM. Under pressure, allocation patterns change. Fragmentation changes. Residency changes. Cache locality changes. All of that changes the system timeline and the feasible plan space. If you want a one line summary that is accurate in 2026 production inference, it is this. Inference is a scheduling problem plus a memory residency problem, and the model is inside that. The Scope First, Let me put it very clear. I am not claiming every deployment is nondeterministic. I am not claiming every kernel variant flips tokens. I am not claiming seeds are useless. I am making a narrower claim, the kind you can defend in an incident review without hand waving. Floating point math is not associative. Order matters. When you parallelize, you change the order of operations, and it is therefore valid for parallel results to differ from a sequential evaluation. NVIDIA states this directly in the CUDA C Best Practices Guide. CUDA also makes a foundational guarantee to the hardware and scheduler, not to your intuition. Thread blocks must be able to execute independently, in any order, in parallel or in series. That freedom is part of the programming model, not an edge case (ref). Now connect those two facts. If accumulation order changes, the last bits can change even when every operation is correct, because floating point addition is not associative. NVIDIA explicitly calls this out as well. Then layer in what serving stacks actually do. Production systems intentionally reshape execution through continuous batching and KV memory management. vLLM is a published example of this co design, where serving throughput is achieved by dynamic batching and memory-aware KV handling. Finally, bridge the nano to the semantic. When early logit margins are small, tiny numeric deltas can reorder the top candidates, and a single token flip is enough to diverge the entire completion. Here is the part that should feel a little scary, because it changes what you think you are operating. Under real load, the system is not just slower. It can enter a different execution regime. Batch composition shifts, shapes shift, workspace and residency shift, and the runtime is forced into a different set of legal kernel and algorithm choices. Nothing “breaks.” No bug is required. The system is still correct by contract. But your output is now a property of the regime you are in, not the demo you validated. That means you can pass every determinism test at idle and still ship a system that drifts only when it matters, at p95 and p99, when queues are long and memory headroom is tight. The first time you notice is often a user screenshot, an audit question, or an incident report where two replicas disagree on the same request because the runtime state was not the same. The equation principals should use in incident reviews Most teams ship with the demo mental model. y = f(x, θ) One prompt in, one checkpoint, one output. If the output changes, someone concludes the weights changed, or “AI is random.” That is not how production inference behaves, because production inference is not just a function. It is execution under constraint. Production behavior is closer to this. y = Decode( Exec(θ, x; s) ) θ is still the same weights. But the thing you actually shipped is Exec, and Exec is chosen. It is chosen per step, under the current state of the system. The behavior you observe is the behavior of the executed plan, not the abstract weights. X is not the prompt. X is the effective request. X is the exact token sequence the model saw after shaping. Truncation, policy injection, tool schema expansion, routing metadata, prefix reuse, safety transforms. All of that can change what the model actually receives. If you cannot reconstruct x, you are not replaying the request. You are replaying an approximation. Here is the minimum you should log for x, even if you cannot store raw text: # minimal "x" record: enough to reproduce or prove you cannot trace_x = { "req_id": req_id, "raw_prompt_sha256": sha256(raw_prompt), "effective_text_sha256": sha256(effective_text), "effective_tokens": len(effective_tokens), "truncated": truncated, "trunc_reason": trunc_reason, # e.g., "latency_guard", "context_cap" "decode_cfg_applied": decode_cfg, # temperature/top_p/max_tokens, etc. "shaping_events": events, # ["policy_inject:v3", "tool_schema:v2", ...] } S is not a vibe. S is the execution state that decides the math. S is what principals should demand in a postmortem, because this is what turns “it drifted” into “this plan executed under this regime.” At minimum, s includes: per-step batch composition and shape class queue delays and scheduling outcomes VRAM headroom and workspace availability cache pressure signals precision path and engine fallbacks distributed timeline signals (TP/PP latency, collective stalls) isolation posture (what batching is allowed) Why this matters: in continuous batching, time becomes part of semantics. A few milliseconds of delay changes who gets co-scheduled at the next token step. That changes shapes. Shapes change kernel/algorithm feasibility. Feasibility changes the numeric pathway. When early logit margins are thin, a tiny pathway delta is enough to flip the argmax. Here is a short, practical “s” record you can emit per decode step: # per-step "s" record: what plan ran, under what pressure step_s = { "req_id": req_id, "step": t, "batch_fp": sha256(",".join(sorted(batch_req_ids)))[:12], "shape": f"q=1,k={klen},h={heads},d={hidden},tp={tp}", "queue_ms": queue_ms, "gpu_ms": gpu_ms, "vram_free_mb": vram_free_mb, "workspace_free_mb": workspace_free_mb, "kv_regime": kv_regime, # "normal" | "pressured" | "paged" "precision_path": precision_path, # "bf16" | "fp16" | "tf32" | "fp32" "algo_id": algo_id, # backend/engine specific "kernel_variant": kernel_variant, # if available "isolation_mode": isolation_mode, # "shared" | "strict" } The incident-review translation If you only ask “what prompt did the user send” and “what weights did we run,” you are using the demo equation. You will argue about seeds, debate “randomness,” and never converge. The production equation forces the real question. Which plan executed, under which constraints, and what state pushed us into that plan. The line principals should repeat until teams internalize it is simple. Weights are static. Behavior is a property of the executed plan. And the executed plan depends on state. If you want one more operational layer that makes this feel real, add a regime marker. Regime changes are where “stability” collapses without any bug: def regime(vram_free_mb, paging_on, isolation_strict, queue_p95_ms): if isolation_strict: return "isolation_strict" if paging_on: return "paging" if vram_free_mb < 1024: return "memory_pressured" if queue_p95_ms > 50: return "queue_degraded" return "normal" When the regime changes, the feasible plan space changes. When the plan space changes, the executed math can change. That is the production reality your incident review must be able to explain. Floating point order is where small deltas are born Let’s break it down without hand waving. Finite precision makes rounding part of the computation Floating point math is not real-number math. Every add and multiply is followed by rounding to the representable format you are using. That rounding is not “noise.” It is part of the computation. Once you accept that, one consequence becomes unavoidable. Order matters. NVIDIA states the rule clearly: floating point involves rounding, and when you parallelize you can change operation order, so parallel results may not match sequential results. Why LLM inference is a perfect storm: reductions everywhere Now connect that to what an LLM does at inference time. LLM inference is reduction-heavy by design. Dot products in GEMMs, attention score accumulation, softmax normalization, layer norm statistics, even top-k selection pathways. These are not single operations. They are many partial operations combined into a final scalar or vector. In floating point, the way you combine partials is the outcome. GPU reductions are staged: partial sums, then merges A reduction on GPU is not “a sum.” It is a staged reduction of partials. On a CPU, you can imagine a left-to-right accumulation: ((((a1 + a2) + a3) + a4) + ...) On a GPU, that mental model is wrong. The GPU is built to run thousands of threads. So it computes partial sums in parallel and then merges them in stages. The staging pattern is determined by kernel design and how the backend maps the problem to hardware. Put the figure here, right after the staging idea lands. The staging depends on decisions you do not control at the prompt layer: how data is tiled into blocks how each block maps to warps how many partials each warp reduces whether it uses warp-level primitives, shared memory, or tensor core fragments how the final merge is staged across blocks Change the tile size, or the block shape, or the occupancy, and you often change the staging order. Change the staging order, and you change when rounding happens. You can get two results that are both correct under IEEE floating point rules, and they differ in the last bits. This is not a bug. It is the contract of finite-precision parallel math, applied at scale. Why the last bits move at the core level Floating point addition is not associative under rounding because rounding happens after each operation. The error introduced at each step depends on the magnitude and sign of what you are adding at that step. When you change the staging order, you change: which numbers get added together early which partial sums get rounded early how cancellation behaves when positive and negative terms interact when large and small magnitudes meet, where small values can lose representable impact That is the core mechanism behind “small deltas.” It is not mystical. It is mechanical. Why this shows up in production serving, not in your demo LLM inference is dominated by massive matrix operations and attention. Under the hood, those paths accumulate across large dimensions. An accumulation is exactly where rounding order matters most. And the server does not always run the same kernel variant for those ops. Under load, shape shifts and workspace pressure can push the backend into different implementations. Different implementations often imply different tiling. Different tiling implies different staging. Different staging implies different rounding. Different rounding implies different last bits. So even with an identical prompt, identical checkpoint, and temperature set to zero, you can still see tiny numeric differences when: batch composition changes and produces different effective shapes the engine picks a different algorithm because workspace is tighter the kernel selects a different tile path due to shape class and occupancy the GPU is in a different pressure regime, changing feasibility and scheduling behavior Those deltas are small, but they are real. And in decoding, small can be enough. The bridge from ulps to language: logits, argmax, divergence A tiny last-bit difference is often irrelevant, Until it hits a decision boundary. At decode step t, greedy decoding chooses an argmax. If the top logits are close, a small delta can swap the ordering. Once token t changes, the context changes, and the completion diverges. That is not randomness. That is deterministic branching from a slightly different numerical pathway. So the actionable takeaway is not “GPUs are nondeterministic.” It is this. Parallel math is allowed to produce multiple correct last-bit outcomes, and LLM decoding can amplify those outcomes into different text when margins are thin. CUDA scheduling makes ordering a form of runtime state CUDA makes a stronger statement than most people realize. Thread blocks must be able to run independently. It must be possible to execute blocks in any order, in parallel or in series. That is why the same kernel can execute with different inter block ordering depending on occupancy, contention, and scheduling. Now bring atomics into the picture. Atomics guarantee correctness of each update. They do not guarantee the arrival order of updates across threads and blocks. When floating point updates arrive in different legal orders, the final sum can differ in the last bits, because floating point addition is not associative. If you do not know what atomic add means, here is the useful definition. Atomic add ensures updates do not overwrite each other. It does not ensure which thread gets there first. This is the nano architecture layer that explains a lot of weirdness. Many engineers assume determinism is a property of weights. In practice, determinism is constrained by the legal reorderings of parallel execution. Logit margin is the bridge from ulps to language Now we connect the last bits to a changed sentence. At decode step t, greedy decoding picks the argmax over logits. Let the top two logits be ℓₐ and ℓ_b. Define the margin: mₜ = ℓₐ − ℓ_b A token flip happens when a small perturbation changes the ordering of these top two. If you want an operational translation, it is this. If the model barely prefers token A over token B, a tiny numeric delta can make it prefer B. Once token t changes, the rest of the completion evolves under a different context. Divergence is expected. This is why I keep pushing one instrumentation idea that sounds boring until you need it. Measure early step margins. You cannot manage stability if you never measure how close the decision boundary is. The effective request problem, the quiet killer of reproducibility Here is the pattern I see in almost every serious production investigation. The team replays the user prompt, cannot reproduce the output, and concludes the model is nondeterministic. Then the incident dies in ambiguity. And then, usually too late, someone asks the only question that matters. What did the model actually see. “In every postmortem, I ask one question before I look at weights, kernels, or seeds: what did the model actually see. If we cannot answer that, nothing else is evidence.” - Hazem Ali In production, the user prompt is not the input. It is an ingredient. By the time a request reaches the model, it has passed through a shaping pipeline that exists to keep the system safe, fast, and multi-tenant. That pipeline is not cosmetic. It can change semantics, length, and even decode behavior. The result is the only input that matters for reproducibility. The effective request. This is the same thesis you have already accepted earlier in the article. y = Decode( Exec(θ, x; s) ) If you do not know x, your replay is not valid. If you do not know s, your replay is not comparable. And if you only log the raw prompt, you are logging neither. Shaping changes semantics, not just length Truncation is the obvious one. Under load, systems often cap context length to protect latency and GPU memory. Same prompt, different truncation boundary, different effective context, different output. Nothing “random” happened. You executed a different input. But truncation is only the beginning. Policy injection can prepend or append system text that changes intent. Tool schema expansion can add hundreds or thousands of tokens and push the request over a context boundary. Routing metadata can select a different template. Prefix caching can reconstruct parts of context from cached state rather than raw text. Safety transformations can rewrite or neutralize content. Even small differences here can shift early logits when margins are thin, and this article already showed how small deltas become different tokens. The worst part is that this is silent by default. The user sees their prompt. Engineers see the prompt in logs. The model sees a different token sequence. Then everyone argues about reproducibility using the wrong input. Why this interacts with load, not just correctness Under low load, your system often has enough headroom to be generous. Longer context, fewer cutoffs, stable routing, more consistent batching, and fewer fallbacks. Under real load, shaping becomes defensive. Dynamic truncation thresholds kick in. Tool schema expansions collide with context limits. Prefix reuse behavior changes. Safety gates can become stricter. The same user text can produce a different effective request, and therefore a different output, precisely when the system is under pressure. So if you are only validating reproducibility at idle, you are validating a different system than the one you ship. What principals should require in telemetry If you want strict reproducibility, you must log the execution contract per request. Not the story. The contract. At minimum: effective token count after shaping truncation boundary and reason final merged decode config actually applied policy gates that modified prompt or decode path whether prefix cache was used, and what cache key was referenced routing template version and system message hash If you are privacy constrained, you still can log hashes and structural facts. You do not need raw prompts to diagnose effective request drift. You need verifiable fingerprints. Here is the short version in one line. If you only log the user prompt, you have not logged x. You have logged an approximation of x. And without x, you cannot claim reproducibility. You can only hope for it. Continuous batching, why time becomes part of semantics This is where principal level thinking matters. Continuous batching does not just increase throughput. It changes the execution context at each token step. Batch composition changes shapes. Shapes influence kernel selection and workspace feasibility. Those choices can change reduction structure and rounding pathways. If you want a published anchor, use vLLM. The PagedAttention paper frames high throughput serving as a need to batch many requests, but KV cache grows dynamically and wastes memory through fragmentation. It proposes PagedAttention and builds vLLM on top of it, with block level memory management and flexible sharing of KV cache to reduce memory usage. (arxiv) Here is what this really means in production. The server is selecting which requests share a step. That changes the math shapes. That changes the executed plan. That is why the same prompt behaves differently under load even at temperature zero. Algorithm selection and engine fallback The hidden variability people forget about If you have ever tried to reproduce a drift across replicas and felt like you were chasing ghosts, this is usually the layer you were missing. Libraries and engines choose, Not in a philosophical sense. In a literal, per-operator, per-shape sense. The same attention call is a fork in the road between multiple legal tactics, each with different tiling, different reduction staging, different fusion boundaries, and different temporary memory requirements. Your checkpoint is the same, your prompt is the same, your temperature is zero, and the output still moves because the executed plan moved. PyTorch says the quiet part directly. Disabling cuDNN benchmarking makes cuDNN deterministically select an algorithm, and PyTorch stresses this is different from the deterministic setting. That is the whole story in one sentence: one switch affects how the backend selects an algorithm, another affects whether the selected algorithms are deterministic. Those are separate layers, and under load they can diverge. Now go down to the core of the core. A tactic is not fast or slow. In production serving, a tactic is legal or illegal under the constraints of this token step. The constraint that forces most plan switches is not compute. It is workspace feasibility. Many high-performance kernels need scratch buffers. Some need enough contiguous space to stage tiles, reorder operands, hold partials, or run fused epilogues. When VRAM is fragmented or headroom drops, a tactic becomes impossible even if it is the tactic you validated at idle. The engine does not throw a warning. It simply selects another legal tactic. That is the first uncomfortable point. The second uncomfortable point is what makes this align perfectly with the next section. The constraint is not only “how many MB are free.” The constraint is the memory hierarchy state of the chip. Under load, two replicas can have the same free VRAM and still be in a different regime because the chip is not one pool of memory. It is HBM plus an on-die L2, plus TLBs, plus page tables, plus a fabric that is arbitrating traffic between SMs, L2 slices, and HBM controllers. When that hierarchy shifts, latency per token step shifts. And in continuous batching, a few milliseconds is not a timing detail, it is a scheduling input. This is how a performance event becomes a behavior event without any bug. The engine’s planner sees a world where a tactic that was “best” at idle is no longer best, or no longer feasible, because the chip is in a different pressure state. Your runtime is still correct. It is just operating a different plan in a different regime. One op, multiple legal kernels. The chosen tactic depends on shape class and feasibility. Now bring TensorRT into the picture, because it makes the precision dimension explicit. TensorRT states TF32 Tensor Core usage is not guaranteed and it can fall back to FP32, and it documents configuration controls around TF32. That statement is not about “precision preference.” It is about the reality that precision is part of tactic selection. Precision changes which instructions execute and how accumulation is staged. When your early logit margins are thin, a small pathway delta can swap the argmax at one step. One token flips, and the rest of the completion deterministically diverges. So “temperature zero” is not a determinism guarantee. Temperature governs sampling. It does not pin the execution pathway. If you want a more mechanical anchor, treat matmul the way NVIDIA exposes it: cuBLASLt has a preference descriptor for applying algorithm search preferences and fine-tuning the heuristic function. That is not marketing. That is the API admitting that algorithm selection is a constrained search problem. Now the part that gets rare, and the part most teams never write down. CUDA’s programming model requires that thread blocks be able to execute independently and may execute in any order, in parallel or in series. This matters here because tactic switches often change block geometry and tiling. Different block geometry changes reduction staging. Reduction staging changes where rounding happens. Even if every operation is correct, last bits can move because you legally changed the staging of partial sums. You do not need randomness. You need a different legal staging tree. Now pull security into the same frame, because it is not a separate layer in production. Security posture changes what the scheduler is allowed to do. Isolation constraints reduce batching freedom. Reduced batching freedom increases tail latency. Tail latency pushes you toward tighter admission controls and more aggressive memory behavior. That shrinks the feasible tactic set sooner. In other words, security decisions can move you across regime boundaries faster, which increases plan switching frequency. Stability becomes an SLO dimension of your security posture, not a property of your weights. This is the business consequence that shows up in the worst possible way. So here is the operational rule I use in reviews. If you cannot prove which plan ran, you cannot claim reproducibility. And that leads to the only practical addition that belongs in this section before we move into VRAM bandwidth and cache residency. VRAM bandwidth, cache residency, and why memory hierarchy becomes control plane input Let’s talk about the performance facts that quietly become behavior facts. And yes, I know how complex this gets. I have watched strong staff and principal engineers get lost here, not because they are weak, but because the system crosses too many layers at once: GPU microarchitecture, allocator behavior, kernel tactics, batching policy, and SLO-driven control loops. No single dashboard shows you the full causal chain. That is exactly why I frame it this way. It is not “performance tuning.” It is a coupled control system. So let me break it down cleanly, from the chip outward, until the behavior change becomes inevitable. NVIDIA describes H100 SXM5 as having HBM3 bandwidth around 3 TB/s and an L2 cache of 50 MB designed to reduce trips to HBM by caching repeated accesses. Most teams read that as “the GPU is fast.” In serving, it is more precise to say: the GPU gives you a memory hierarchy with regimes, and your runtime is forced to adapt to whichever regime you are currently in. The chip-level model you should carry in your head Decode is not one big matmul. It is a loop that repeatedly touches a shifting working set: KV blocks for the active sequences attention metadata (block tables, indirection, masks) sampling buffers (logits, top-k/top-p structures) runtime bookkeeping for continuous batching Those accesses are not purely streaming. They are pointer-heavy, and their locality depends on how your KV is laid out, which requests are co-scheduled, and how fragmented your memory becomes under churn. Here is the simplest mental model that is still honest: B_HBM is the number of bytes actually read from HBM during this step. B_L2miss is the number of bytes that missed L2 and therefore had to be fetched from HBM. t_translate is the address-translation tax: extra time from TLB misses and page-table walks. That last term is the one that surprises people. It’s “invisible” until it dominates. Why L2 residency becomes a control-plane input Now connect that to decode, Decode repeatedly reads KV state. If L2 hit rate drops, HBM traffic rises. When HBM traffic rises, stalls rise. When stalls rise, token-step latency shifts. When token-step latency shifts, the server changes batching decisions. This is the control loop you should keep in your head: L2 hit rate ↓ → t_step ↑ → Δt ↑ → batch composition changes → shape class changes → tactic set changes That is the bridge from “cache miss” to “different plan executed.” In continuous batching, time is not just an output metric. Time is an input into the next scheduling decision. A few milliseconds can change who gets co-scheduled at the next token step. That changes shapes. Shapes change feasible kernels and algorithms. That changes the executed math. And if early logit margins are thin, a small pathway delta can flip a token and send the rest of the completion down a different branch. Rare but matters: the translation tax that breaks the “free VRAM” illusion Two replicas can report similar free VRAM and still be in different regimes. Why? Because the chip is not “a pool of memory.” It is an on-die cache, translation structures, page tables, and a fabric that is arbitrating traffic under pressure. When KV is stored in blocks (or pages) and those blocks are scattered due to churn, you often get: worse spatial locality more distinct memory regions per step more TLB pressure more page walks Page walks are not abstract. They are memory reads. They compete with your payload reads. Under real load, this turns into self-inflicted HBM traffic. So you can be “bandwidth rich” on paper and still be “latency poor” in practice because the working set became translation-hostile. This is how a performance event becomes a behavior event without any bug. A concrete KV bandwidth sanity check If you want a back-of-the-envelope check for why decode becomes memory-shaped, use a conservative estimate. Per token step, you often need to read a large portion of KV for the active context. A rough model is: KV bytes per step ≈ 2 × B × L × H × D × s Where: B is batch size (number of sequences co-scheduled in the step) L is current context length (tokens already in KV) H is the number of attention heads (or KV heads, depending on the model) D is head dimension s is bytes per element (2 for fp16/bf16, 1 for int8, etc.) The factor 2 accounts for K and V. Even if your kernel is compute-efficient, you are still moving a lot of bytes. If locality collapses and L2 misses rise, you shift into an HBM-limited regime fast. That is the mechanical reason your p95/p99 step time moves under load, even with the same checkpoint and temperature. Business impact, stated plainly This is why drift shows up where it hurts: p95 and p99. At idle, L2 residency is generous, fragmentation is lower, translation pressure is calmer, and step time is stable. Under load, residency collapses, translation tax rises, allocator feasibility tightens, step time stretches, and your control plane adapts by changing batching and shapes. That can move you into different execution plans without any model change. An enterprise buyer does not care whether you call it “L2 miss driven plan churn.” They care that two identical requests disagree and you cannot explain it. So the takeaway I want principals to internalize is simple: In continuous batching, memory hierarchy state is control-plane state. It shapes latency. Latency shapes batching. Batching shapes shapes. Shapes shape feasibility. Feasibility shapes the executed plan. That is how “performance” becomes “behavior.” Multi node tensor parallel, the execution plan extends across the fabric Once you go multi-node tensor parallel, you add a second execution plane that most teams underestimate. You are no longer operating only a GPU runtime. You are operating a distributed timeline. And the timeline is not a background detail. In continuous batching, the timeline becomes a control input that reshapes batching, shapes, and eventually the executed plan. Let me be precise about what I am claiming, and what I am not. I am not going to claim collectives reorder arithmetic inside a kernel. That would be sloppy. The correct claim is this: Distributed synchronization changes the timeline. The timeline changes admission and batching. Batching changes shapes. Shapes change which plans are legal. That’s enough to explain why the “same prompt, same checkpoint, temp=0” can drift only under real load. The minimal equation you should carry At each decode step, your latency is no longer “GPU time.” It’s GPU time plus fabric time: t_step ≈ t_compute + t_comm + t_sync And the part that hurts is that t_comm and t_sync are not stable. They are affected by contention, queueing, stragglers, and topology. A useful mental model for the communication piece is the classic latency–bandwidth form: t_comm(message) ≈ α + (n / β_eff) α is the per-collective startup and synchronization overhead n is bytes moved β_eff is the effective bandwidth you actually get under contention In isolation, this looks like performance math. In a continuous batching server, this becomes behavior math, because t_step feeds back into the next scheduling decision. What actually happens in multi-node TP at token cadence Tensor parallelism shards the model across devices. Every token step requires cross-device coordination for some portion of the layer execution. In practice, this means collectives become part of the critical path. NCCL’s collective ops are explicit about the semantics: for example, AllReduce reduces values across ranks and returns identical results to all ranks. That tells you what the runtime must do: it must wait for coordination across ranks before progressing. So the decode loop becomes: execute local compute for this step hit a collective boundary wait for the slowest rank to finish and for the fabric to deliver proceed That “slowest rank” detail is the piece people feel but rarely name. In distributed inference, p99 is often a straggler story. A single congested link, a slightly delayed rank, or a transient fabric stall turns into a global stall because collectives synchronize progress. In other words, a multi-node TP system behaves like a coupled oscillator: the fastest GPU is still gated by the slowest collective. Why this changes the executed plan, not just the latency Here’s the bridge to the thesis of the whole article. In a continuous batching server, you do not just execute requests. You continuously reform microbatches at token cadence. That means step time affects who joins the next step. And in multi-node TP, fabric jitter is one of the biggest sources of step-time variability. So when comm jitter shifts t_step, it shifts the schedule: queue delay changes microbatch membership changes effective shape class changes workspace feasibility changes tactic choice changes You already established earlier that a changed shape class can force a different tactic set. Multi-node TP adds a new reason shape churn happens: not only GPU pressure, but fabric timing pressure. So the claim stays clean and defensible: Distributed synchronization doesn’t need to change arithmetic to change behavior. It only needs to change the timeline that drives batching. Chip-to-fabric reality: why infrastructure details belong in the reproducibility record At this scale, the infrastructure is part of the runtime. According to Azure Docs, Azure’s ND H100 v5 series is explicitly positioned for tightly coupled scale-up and scale-out Generative AI and HPC workloads, and it’s built around the idea that the fabric matters, not just the GPUs: If you are running multi-node TP in production, treat fabric telemetry as part of your reproducibility record. Not because it is fun. Because it changes the system timeline that drives batching. A practical minimum is to track per-step: collective type on the critical path (e.g., all-reduce / all-gather) comm time and jitter (p50/p95/p99 per step window) rank skew (max(rank_time) − min(rank_time)) effective bandwidth estimate (n / t_comm) retransmit / congestion signals if your stack exposes them a “fabric regime” marker: normal vs congested vs degraded When drift becomes expensive This is one of the reasons enterprise teams report the most confusing failures only at load. At idle, your timeline is stable, your microbatches are stable, your shapes are stable, and your plan selection is stable. Under real load, the fabric introduces jitter, jitter reshapes batching, batching reshapes shapes, and shapes reshape the executed plan. Now two replicas can disagree, not because the model changed, but because the timeline differed. That shows up as: inconsistent answers across replicas in high-stakes workflows reproducibility failures during audits and incident reviews “regressions” after scaling out, even with the same checkpoint and code support costs and credibility loss because you cannot explain why behavior changed only at p95/p99 So the operational sentence I want you to carry into your postmortems is: In multi-node tensor parallel inference, the execution plan extends across the fabric. If you do not log the fabric timeline, you are missing part of the runtime state that decides which plan was feasible. Where Infrastructure Stops Being “Just Infrastructure” Once you accept the thesis of this article, one conclusion becomes unavoidable: cloud choices are not just cost and convenience decisions. They shape which execution regimes your runtime will enter under pressure. At scale, you are no longer buying “GPUs.” You are buying: A fabric and topology that holds up under synchronized token-step collectives A VM family with predictable characteristics for tightly coupled scale-out workloads (the kind multi-node inference actually is) An isolation posture that can be enforced in hardware when your threat model requires it, without hand-waving away the runtime implications First-class observability for GPU behavior, not just CPU and request traces, so you can correlate drift with the state variables that caused it (for example, exporting NVIDIA DCGM metrics into managed Prometheus and Azure Managed Grafana on AKS). This is the quiet reason certain platforms feel “more stable” in production. Not because the model is different, but because the runtime state is easier to constrain, measure, and explain when the underlying infrastructure is designed for the exact regime you’re operating in. Quantization effects on execution paths and causal stragglers in multi-node TP Let me be direct about what most articles miss when they discuss distributed inference at scale. The conversation typically stops at "how many GPUs" and "what's the bandwidth." That's not wrong. It's just incomplete. What's missing is the interaction between quantization-induced plan churn and straggler amplification in the collective path, two forces that quietly reshape your execution regime under VRAM pressure and fabric contention. These are not theoretical curiosities. They are production realities at 100+ GPU scale, the kind of scale where you can no longer afford to treat quantization as a "precision choice" or stragglers as a "latency outlier." At that scale, they become causal inputs to your runtime's decision surface. Quantization variability: not just precision, but plan selection When teams talk about INT8 or FP8 quantization, the conversation usually centers on memory savings and throughput gains. That's the marketing layer. The execution layer is more nuanced: quantization changes which kernels are legal, where fusion boundaries land, and how reduction trees are staged. Here's what I mean in concrete terms. Under VRAM pressure, your serving stack may need to requantize activations mid-forward-pass to stay within memory bounds. That requant step is not "free" in the plan sense. It introduces: dequant/requant cycles that break fusion opportunities you had in the FP16 path new non-associative operations in the reduction tree, where rounding happens at different stages fallback paths when the quantized kernel variant lacks workspace or doesn't support the current shape class Let me state this in the language of the article's thesis: quantization is not a data type. It is a tactic constraint that reshapes the feasible plan space. Memory pressure can force dequant/requant cycles, change fusion boundaries, and trigger fallback kernels with different reduction staging, producing last-bit differences that can flip tokens during decoding. The practical consequence? Two replicas running "the same quantized model" can execute different kernel variants when one is memory-pressured and the other is not. The memory-pressured replica may be forced into a fallback path with different reduction staging. Different staging means different rounding order. Different rounding order means different last bits. And in decoding, last bits can become different tokens. I've watched incident reviews where teams assumed INT8 was "deterministic" because they set the quantization scheme once at export time. What they missed is that the runtime's quantization pathway depends on the state of VRAM fragmentation, workspace availability, and kernel preference histograms, exactly the regime-dependent variables we've been building toward throughout this article. If you're operating at scale, instrument this. Track: per-step kernel selection via cuBLASLt preference descriptors dequant/requant cycle counts when memory pressure rises fallback events when preferred quantized tactics become infeasible whether the executed plan matched the "expected" quantization pathway This is rare telemetry. Most teams never see it because they're not running large enough clusters under sustained pressure. But once you cross into 100+ GPU inference workloads, quantization-induced plan churn becomes visible in your p99 drift signatures. Causal stragglers: when one rank's fallback stalls the collective Now let's talk about the fabric-scale pathology that couples with everything we just discussed: head-of-line blocking in distributed tensor parallelism. You already know from the multi-node TP section that collectives synchronize progress. The fastest rank waits for the slowest. That's the contract. What's less documented—and what I've only seen formalized in internal NVIDIA serving postmortem templates—is how a single rank's kernel fallback can become a collective-wide straggler, and how that straggler amplifies through the batching feedback loop. Here's the causal chain: One rank enters memory pressure. Maybe fragmentation is worse on that device, maybe it's handling a slightly different KV layout due to request assignment. That rank falls back to a slower tactic. The preferred kernel requires workspace. Workspace isn't available. The engine selects a legal fallback. The fallback kernel takes longer. Not by seconds—by milliseconds. But in a collective, milliseconds matter. The collective waits. AllReduce can't proceed until all ranks contribute. The straggler becomes the bottleneck. Step time stretches. The stretched step reshapes the next batch in continuous batching. Different batch, different shapes, different feasibility. The cycle repeats. Now multiple ranks may be in fallback paths. The p99 drift you're seeing isn't random—it's a feedback loop. This is what I call a causal straggler: not just a slow rank, but a rank whose performance degradation causally reshapes the execution regime of the entire TP group. And here's where quantization and stragglers intersect. If one rank is under more VRAM pressure and is forced into more frequent dequant/requant cycles, it becomes the straggler. Its quantization pathway differs from the other ranks—not because the model changed, but because the memory regime changed. That difference in pathway becomes a difference in step time. That difference in step time becomes a collective stall. That stall becomes a batching change. That batching change becomes a new plan. The output drifts, and you're left wondering why "the same checkpoint at temperature zero" produced different text only under load. The answer is: you weren't in the same execution regime. You were in a regime where one rank's memory pressure caused a straggler, the straggler caused a timeline shift, and the timeline shift caused a plan change. Rarity value: why this knowledge is elite production battle scars Let me be honest about why these gaps are rare. Most teams never operate at the scale where these effects dominate. If you're running inference on 8 GPUs, you might see hints of this. At 100+ GPUs with multi-node TP and continuous batching under sustained load, it's no longer a hint—it's the signature. The teams that do operate at this scale track: cuBLASLt preference histograms to detect when algorithm selection is churning across steps NCCL timeline traces to identify straggler signatures and correlate them with per-rank memory state per-rank kernel fallback events to see when one device is operating a different plan than its peers quantization pathway divergence across ranks under pressure This is the telemetry that doesn't show up in tutorials. It shows up in postmortems at hyperscaler SLO thresholds, where p99 latency violations trigger incident reviews and someone finally asks: "Why did replica 3 disagree with replica 1 only during the peak load window?" The article you're reading now covers single-node memory regimes beautifully. What bridges to 10/10 elite production knowledge is this: fabric-scale causality. The understanding that in multi-node TP, your execution regime is not just shaped by your GPU's memory state—it's shaped by the worst GPU's memory state, because collectives couple everyone's timeline. That's the gap. That's the rarity value. And if you're building or operating inference at 100+ GPU scale, that's the layer where your next outage is hiding. Peak depth: wavefront divergence, tensor core fragmentation, NCCL backpressure, and ISR collision Everything above operates at the principal and staff engineer level. What follows is the layer below that—the chip architect handoff, where you stop talking about "plans" in the abstract and start talking about warp stall cycles, tensor core fragment occupancy, NCCL retransmit chains, and memory evaporation under replication pressure. I'm writing this section because it's the part I never see published outside internal design reviews, and because these are the exact pathologies that turn a well-architected inference cluster into a system that disagrees with itself only during peak traffic. "Most engineers debug the layer they understand. The system breaks at the layer they don't. In production inference, that layer is almost always the one where microarchitecture meets scheduling meets the fabric." — Hazem Ali Wavefront divergence in decode attention kernels Let me take you inside the warp. In SIMT execution, a warp is 32 threads executing in lockstep. When all threads follow the same control path, you get full utilization. When they diverge—different threads take different branches—the warp must serialize both paths. That's textbook GPU architecture. What's not textbook is how this interacts with paged KV attention in production decode loops. In a paged KV system (the exact kind vLLM introduced), KV blocks are scattered across VRAM. Different sequences in the same microbatch may have their KV blocks in different residency states: some hot in L2, some cold in HBM, some partially evicted under paging pressure. When the attention kernel issues loads for KV blocks, threads within the same warp can stall at different rates depending on which blocks they're accessing and where those blocks reside. This creates a subtle but measurable pathology: Lane divergence inside the attention kernel. Not control-flow divergence in the traditional sense, but memory-latency divergence: some lanes return fast (L2 hit), some stall (HBM fetch), and the warp can't retire until the slowest lane completes. Register pressure amplification. When warps stall, the SM must keep their register state live. Under heavy stalling, register pressure rises, which can force the compiler to spill to local memory (which lives in L2/HBM). Spills create more memory traffic, which creates more stalls. It's a feedback loop at the microarchitectural level. Measurable p99 step variance in identical-shape batches. This is the part that confuses teams. Two consecutive decode steps with the same batch size and the same sequence lengths can have different step times, because the KV block residency pattern differed. The shape was identical. The memory topology was not. If you want to see this in practice, the tool is Nsight Systems. What you're looking for: # Nsight Systems trace analysis: partition warp stall cycles # Look for these stall reasons in the GPU metrics view: # - smsp__warps_issue_stalled_long_scoreboard → memory dependency stalls # - smsp__warps_issue_stalled_short_scoreboard → register dependency stalls # - smsp__warps_issue_stalled_no_instruction → instruction cache miss # # Correlate with: # - l1tex__t_sectors_pipe_lsu_mem_global_op_ld → global load sectors (KV fetches) # - lts__t_sectors_srcunit_tex_op_read_hit_rate → L2 hit rate during attention # # The diagnostic signal: when stall_long_scoreboard spikes correlate with # L2 hit rate drops, you're seeing KV residency divergence across warps. The stall partition tells you why the warp stalled. When you see long_scoreboard stalls dominating during attention kernels—and you see them correlating with L2 miss rate fluctuations—you're observing exactly the KV residency divergence I'm describing. The warp is waiting for scattered KV blocks, and the scatter pattern changes with every batch because paging decisions are state-dependent. This is how "identical shapes" produce different timelines. The shape is the same. The KV block map is not. And the block map is a function of runtime allocation history—the same state-dependent variable that drives everything else in this article. Tensor core fragment utilization collapse under shape churn Now let's go inside the tensor cores themselves. H100 and Blackwell tensor cores operate on matrix fragments—fixed-size tiles that map directly to the hardware's matrix multiply-accumulate units. On H100, the native fragment sizes for FP16 are typically 16×16×16 (m×n×k). When your operand dimensions align cleanly with fragment boundaries, you get full utilization. When they don't, you get fragment waste: the hardware still executes full fragments, but some of the lanes carry padding zeros. In continuous batching, shape churn is the norm. Your microbatch dimensions change at token cadence. And this is where a subtle but devastating efficiency collapse hides. Consider two microbatches that arrive one step apart: # Step t: B=16, L=2048 → GEMM shape aligns cleanly with 16×16 fragments # Fragment utilization: ~98% # cuBLASLt selects: WMMA-based kernel (tensor core native) # # Step t+1: B=17, L=2047 → GEMM shape straddles fragment boundaries # Fragment utilization: drops below 25% on trailing tiles # cuBLASLt selects: fallback to non-WMMA FP16 kernel # (or WMMA with heavy padding, depending on heuristic) The difference is one sequence in the batch and one token in context length. The performance consequence is that the runtime switches from tensor core native execution to a scalar FP16 path. That's not a minor variant. That's a fundamentally different instruction mix, a different reduction tree, and a different accumulation order. The ulp deltas that result from this switch don't stay contained in the GEMM output. They propagate forward through layer normalization—which is itself a reduction over the hidden dimension. Layer norm amplifies small differences because it divides by a variance term computed from the same values. A tiny shift in the GEMM output becomes a slightly different variance, which becomes a slightly different normalization, which becomes a slightly different input to the next layer's attention. You can observe this directly via cuBLASLt's algorithm preference reporting: # cuBLASLt algorithm preference histogram (conceptual) # Track per-step which algorithm ID was selected for the primary GEMM # # Healthy (stable shapes): # algo_id=42 (WMMA_TENSOR_OP_HMMA_16816) → 99.2% of steps # algo_id=17 (SIMT_FP16_SPLITK) → 0.8% of steps # # Under shape churn (continuous batching, mixed lengths): # algo_id=42 (WMMA_TENSOR_OP_HMMA_16816) → 61.3% of steps # algo_id=17 (SIMT_FP16_SPLITK) → 22.1% of steps # algo_id=31 (WMMA_TENSOR_OP_PAD16) → 16.6% of steps # # When algo_id distribution churns, your reduction tree is churning. # When your reduction tree churns, your last bits are churning. # When your last bits churn under thin margins, your tokens can flip. That histogram is the smoking gun. When you see algorithm preference distribution widening under load, you're watching the tensor cores get destabilized by shape churn. The fix isn't "use bigger batches." The fix is to understand that continuous batching creates a shape distribution, not a fixed shape, and that shape distribution maps directly to a tactic distribution, which maps directly to a ulp distribution. NCCL causal backpressure chains across TP+DP pods Now scale this to the fabric. Take an 8×TP + 4×DP pod: 32 GPUs total, where every token step requires AllReduce across the 8-way TP group, and gradient synchronization (or KV redistribution in some architectures) across the 4-way DP group. Here's the causal backpressure chain I've traced in production, laid out as a timeline: Rank 5 (of 8 TP ranks) hits a quant/dequant stall. Its KV blocks are fragmented, workspace is tight, and the runtime forces a dequant cycle mid-attention. That adds ~1.2ms to this rank's compute. AllReduce stalls on Rank 5. The other 7 ranks complete their portion and issue their NCCL send. Rank 5 hasn't arrived yet. NCCL's ring/tree protocol can't progress past this rank. Effective t_sync inflates by 2× compared to the no-straggler baseline. P2P retransmit triggers. Under some fabric topologies and congestion states, the delayed arrival from Rank 5 can cause NCCL to hit internal retry logic on the NVLink or InfiniBand path. This is not a "network error"—it's the transport protocol managing flow control under backpressure. But it adds latency jitter that is invisible unless you're tracing at the NCCL bootstrap level. vLLM scheduler reacts to the stretched step. The scheduler sees that step t took 2× longer than expected. Under its latency-aware admission control, it drops batch size from 32 → 12 to protect SLO. Smaller batch means different shapes. Different shapes mean different tactics. The plan changes. The batch size drop propagates. With batch size at 12, queued requests wait longer. Queue pressure builds. When the scheduler recovers and re-admits, the burst creates shape churn. Shape churn destabilizes tensor core fragment utilization. The system is now in a different execution regime—triggered by one rank's memory fragmentation. That is a causal backpressure chain. Not a latency spike. Not a network blip. A causally connected sequence where a microarchitectural event on one device reshapes the execution plan across the entire pod. To trace this, you need NCCL bootstrap traces with NVTX domain annotations: # NCCL tracing with NVTX domains for causal analysis # # Environment setup for trace collection: # NCCL_DEBUG=INFO # NCCL_DEBUG_SUBSYS=INIT,COLL,P2P # NSYS_NVTX_DOMAINS=nccl,cuda,cublas # # In Nsight Systems, correlate: # 1. Per-rank kernel duration (cuda domain) — identify the straggler # 2. NCCL collective start/end (nccl domain) — measure t_sync inflation # 3. P2P transport events (nccl/P2P) — detect retransmit/backpressure # 4. Scheduler batch decisions (application NVTX) — see batch size reaction # # The causal signal: when rank N's kernel duration spike aligns with # NCCL collective inflation across all ranks, followed by batch size # reduction in the scheduler, you have a causal backpressure chain. # # Regex for filtering straggler events in nsys export: # grep -E "ncclAllReduce.*duration_us > (2 * median_duration)" trace.sqlite # → correlate timestamp with scheduler batch_size change events This is the telemetry that separates "we think there was network jitter" from "Rank 5's dequant stall caused a 2× collective inflation that forced the scheduler to halve batch size, which shifted the shape class into a non-WMMA tactic for the next 47 steps." The first is a guess. The second is a causal explanation. And in an incident review at scale, only the second one survives. ISR + checkpoint overlap pathology: memory evaporation under replication pressure This is the deepest pathology in this article, and it almost never surfaces below 512 sequences per second. Large-scale inference deployments use incremental state replication (ISR) for fault tolerance: rather than checkpointing the entire model state, you replicate KV cache deltas and scheduler state to a standby node incrementally, so failover is fast. Separately, many systems run async checkpointing for recovery: periodic snapshots of model and optimizer state written to persistent storage, overlapped with inference to avoid blocking the decode loop. Under normal load, these two systems coexist peacefully. ISR replicates small deltas. Checkpointing writes in the background. Memory headroom is sufficient for both. Under paging pressure—the exact regime we've been discussing throughout this article—they collide. Here's the pathological interaction: The system is under VRAM pressure. KV blocks are being paged (allocated, evicted, re-allocated) at high frequency. Memory headroom is thin. ISR kicks in. It needs to replicate recent KV deltas to the standby. To do this, it must pin certain KV blocks in memory while it serializes and transmits them. Async checkpointing overlaps. The checkpoint writer is also holding references to memory regions it's snapshotting. Under normal conditions, this is fine—there's enough headroom. Under paging pressure, the checkpoint's memory holds compete with ISR's memory holds. Memory evaporation. The combined pinning from ISR + checkpointing temporarily removes KV blocks from the pool available to the decode loop. The pager sees available blocks drop. It may be forced to evict active KV blocks—blocks that are needed for in-flight sequences—to make room. Evicted blocks must be recomputed. When a sequence's KV is evicted mid-collective (during an AllReduce, for example), the rank that lost its KV must recompute it. That recompute makes this rank the straggler. And we already know what stragglers do to the collective timeline. The straggler triggers the full backpressure chain. Collective stall → batch size reduction → shape churn → tactic churn → output drift. All caused by a fault-tolerance mechanism designed to keep you safe. ISR pins KV deltas for replication while async checkpointing pins regions for snapshotting. Under paging pressure, the combined pinning shrinks the decode-available KV pool, forces evictions and recompute, creates stragglers, and cascades into collective stalls → batch reduction → shape/tactic churn → p99 output drift. I call this memory evaporation because from the decode loop's perspective, VRAM that was available simply vanishes for a window of time. The blocks are still physically present—they're held by ISR and the checkpointer, but they're not available to the runtime. The effect is identical to a sudden drop in free VRAM, and the runtime reacts accordingly: it enters a pressured regime. This is why the pathology rarely surfaces below 512 seq/s. At lower throughput, there's enough headroom that ISR and checkpointing never compete meaningfully with the decode loop's memory needs. At high throughput under sustained load, the margins collapse, and the three systems—decode, ISR, checkpoint—start fighting over the same memory. The fix is not "turn off ISR." The fix is to coordinate memory budgets across these three subsystems and to treat ISR and checkpointing as memory consumers that participate in the regime calculation. If your regime function doesn't account for replication and checkpoint holds, it's underestimating pressure, and your system will surprise you at exactly the scale where fault tolerance matters most. # extended regime function accounting for replication and checkpoint pressure def regime_extended(vram_free_mb, paging_on, isolation_strict, queue_p95_ms, isr_pinned_mb, ckpt_pinned_mb, kv_pool_total_mb): effective_free = vram_free_mb - isr_pinned_mb - ckpt_pinned_mb effective_ratio = effective_free / kv_pool_total_mb if kv_pool_total_mb > 0 else 1.0 if isolation_strict: return "isolation_strict" if effective_ratio < 0.05: return "memory_evaporation" # ISR+ckpt collision if paging_on: return "paging" if effective_free < 1024: return "memory_pressured" if queue_p95_ms > 50: return "queue_degraded" return "normal" That "memory_evaporation" regime is the one you never see at idle. It only appears when throughput is high enough that ISR frequency, checkpoint frequency, and decode memory demand all peak simultaneously. And when it appears, it doesn't show up as an OOM. It shows up as a straggler, which shows up as a collective stall, which shows up as a batch size drop, which shows up as a shape change, which shows up as output drift at p99. That's the full causal chain from fault tolerance to token flip. The chip-architect handoff These four pathologies, wavefront divergence, tensor core fragmentation, NCCL backpressure, and ISR collision are what elevate from principal-level operational insight to chip-architect-level systems thinking. They share a common structure: A microarchitectural or infrastructure event occurs that is invisible at the API layer. The event changes the timeline or the memory topology, not the "inputs." The changed timeline or topology feeds back into scheduling, shaping, or tactic selection. The feedback loop produces a different executed plan. The different plan produces a different result that is correct by contract but different by observation. If you're instrumenting at this depth, you're not debugging anymore. You're operating a system where the observability itself is part of the architecture. And if you're carrying the thesis of this article to its logical conclusion: the executed plan is not just a function of the GPU state. It's a function of the warp state, the fragment state, the fabric state, and the replication state—all coupled through continuous batching at token cadence. Security is not a layer, it changes execution Now let’s go deep, because this is where a lot of principal level reviews go wrong. Teams talk about security as confidentiality and correctness as something separate. In multi tenant inference, they couple. IOMMU based GPU isolation and DMA remapping Microsoft documents IOMMU based GPU isolation as a technique to manage how GPUs access system memory, improving security and stability: Microsoft also documents IOMMU DMA remapping, describing how GPUs access memory through logical addresses that are no longer mapped one to one, enabling logically contiguous address ranges through translation: This matters for two reasons. First, it is a real hardware enforced boundary, not a policy checkbox. Second, boundaries introduce overhead and constraints. Constraints change what is allowed. Allowed execution choices shape the plan space. Confidential computing on H100 NVIDIA states that H100 is the first GPU to introduce support for confidential computing and that it can be used in virtualized environments with VMs or Kubernetes based deployments. Azure has also published general availability of confidential VMs with H100, which is the practical deployment side of this posture: Now the key architectural point. When you turn on stronger isolation, you often restrict sharing. You restrict cross tenant microbatching. You add attestation requirements. You change how memory is mapped and protected. That can reduce throughput. Reduced throughput moves you closer to regime boundaries. When the system crosses a regime boundary, the executed plan changes. Security posture becomes an SLO dimension. If you do not test it, you do not know what system you are running. GPU cache side channels, why sharing is not a theoretical risk There is published research that treats GPU caches as a leakage surface. The USENIX Security 2024 paper Invalidate plus Compare presents a timer free GPU cache attack primitive. I will not provide attack recipes. You do not need them to understand the conclusion. If your threat model includes untrusted co tenants, shared microarchitectural resources matter. If you respond by increasing isolation, your execution constraints change. That changes performance and can change the execution regimes your serving stack enters. Security and runtime behavior are coupled. State collapse, the phase transition that looks like model instability If you don’t know what state collapse is, imagine a highway that looks perfectly calm at 2 a.m. Every lane is open. Every car keeps its distance. Your ETA is stable. You run the same route ten times and you get the same arrival time. Then 8:30 a.m. hits. Nothing “broke” in the highway. The asphalt is the same. The speed limit is the same. The cars are the same. But the system crosses a density threshold. One small brake tap becomes a shockwave. Lanes start interacting. Merges become bottlenecks. A single slow truck creates a queue that ripples backwards. Suddenly your ETA isn’t a property of your car anymore. It’s a property of the traffic regime. That is state collapse in production inference. At low load, the system behaves stable. At high load, output drift appears. And teams mislabel it as “model instability,” or “LLM randomness,” or “temperature drift.” Most of the time, it is none of that. It is a phase transition in the runtime. You didn’t change weights. You crossed a regime boundary. What collapses, exactly State collapse is not “everything gets slower.” It is when the control plane loses the degrees of freedom it was using to keep execution consistent. Under low load, the runtime has slack: enough VRAM headroom to keep preferred tactics feasible enough cache residency to keep step times predictable enough scheduling flexibility to keep microbatch composition stable enough workspace contiguity to avoid algorithm fallbacks enough fabric stability (in multi-node TP) to keep step cadence tight Under high load, that slack disappears. The runtime stops being a “fast executor” and becomes a “survival scheduler.” And once it crosses that boundary, it starts making different decisions that are all valid, all correct by contract, and all capable of shifting outputs. This is why it feels like instability: the model hasn’t changed, but the executed plan has. Why this shows up as output drift, not just latency drift Because decoding is a branching process. A small numerical difference that does nothing in a benchmark can flip a token if the margin is thin. One flip changes the context. The context changes the next logits. Now you’re on a different path. So the runtime doesn’t need to be “wrong” to produce different text. It just needs to execute a different legal plan under a different legal regime. That is the whole thesis of this article, condensed into one sentence: Weights are static. Behavior is a property of the executed plan. The executed plan is a function of state. The common triggers that push systems into collapse You can treat these as the usual “threshold crossings” that shrink the feasible plan space: Memory headroom shrinks → feasible tactic set shrinks Preferred kernels often require workspace. When headroom or contiguity drops, tactics become illegal and the engine selects other tactics. Cache residency collapses → stalls rise → step timing drifts L2 hit rate drops, HBM traffic rises, and decode steps stretch. In continuous batching, stretched steps reshape the next batch. Continuous batching shifts the mix and shapes Under load, microbatch membership changes at token cadence. Shape class changes are not cosmetic; they change kernel feasibility. Framework and engine algorithm selection changes depending on settings Autotuning, benchmarking, and backend heuristics mean the “same op” can legally choose different algorithms. Under pressure, the best choice can become infeasible. CUDA execution permits ordering freedom and floating point order sensitivity remains true Parallel staging and legal reordering can shift last bits. Under thin margins, last bits can become different tokens. Nothing here requires a bug. This is what “execution under constraint” looks like. The incident question that stops the hand-waving If you want a more honest incident question, use this: Which execution regime ran, and what constraints pushed us into it? Not “was the prompt the same.” Not “were the weights the same.” Not “did we set temperature to zero.” Regime first. Because state collapse is not a mystery. It’s a threshold. And once you learn to name the threshold, you can instrument it, test it, and stop being surprised by it at p95 and p99. A reproducibility protocol that works for principals, not demos Logging prompts is not reproducibility. It is wishful thinking. If you want to be able to defend behavior, you need to reconstruct the execution state. Log the execution contract Per request, log: effective input length after shaping truncation boundary and reason decode configuration actually applied admission time, queue time, GPU time per step batch fingerprint or at minimum batch identity and shape class memory headroom watermark and whether you were in a pressured allocation regime engine precision mode settings and any fallback relevant flags cuDNN benchmark and deterministic settings if relevant isolation posture, including whether cross tenant batching is permitted Track margins early Track top two logit margins for early steps. Use it as a stability budget. If the margin collapses under a certain prompt family, treat that as a risk surface. Not every prompt is equally stable. Test under regimes, not at idle Do not run determinism tests at idle and call it solved. Test under: sustained concurrency mixed sequence lengths continuous batching realistic memory pressure real isolation posture If you do not do this, you are validating a different system than the one you ship. vLLM’s paper exists precisely because these conditions define the serving problem. Closing If you want production LLM behavior to be explainable, stop treating the model as the whole system. Weights are static. Executed math is selected under constraint. Behavior lives in the gap. You did not deploy weights. You deployed a physics constrained runtime that contains weights. And that runtime is allowed to change the executed plan, because floating point order matters, CUDA scheduling freedom is part of the contract, engines can choose precision pathways, and serving stacks intentionally reshape batching and memory. Acknowledgments While this article dives into the hidden memory mechanics that shape LLM behavior under load, I’m grateful it was peer-reviewed and challenged before publishing. A special thanks for Hammad Atta and Abhilekh Verma for peer-reviewing this piece and challenging it from a security-and-systems angle. If this article resonated, it’s likely because it describes a reality many teams encounter only after an incident: production LLM behavior is a property of the executed plan, and the executed plan is a function of state. If you’re running production inference at scale and observing behavior shifts under load—especially in tail-latency regimes, I’m happy to connect on LinkedIn. I’m open to substantive technical discussion. Thank you for reading. I hope this helps you surface the hidden variables in serving and turn them into telemetry, controls, and repeatable postmortem evidence. And if you’re seeing similar regime transitions or plan churn in your own deployments, I’d be interested to hear how it presents in your stack. — Hazem Ali Microsoft AI MVP, Distinguished AI & ML Engineer / ArchitectHow to Set Up Claude Code with Microsoft Foundry Models on macOS
Introduction Building with AI isn't just about picking a smart model. It is about where that model lives. I chose to route my Claude Code setup through Microsoft Foundry because I needed more than just a raw API. I wanted the reliability, compliance, and structured management that comes with Microsoft's ecosystem. When you are moving from a prototype to something real, having that level of infrastructure backing your calls makes a significant difference. The challenge is that Foundry is designed for enterprise cloud environments, while my daily development work happens locally on a MacBook. Getting the two to communicate seamlessly involved navigating a maze of shell configurations and environment variables that weren't immediately obvious. I wrote this guide to document the exact steps for bridging that gap. Here is how you can set up Claude Code to run locally on macOS while leveraging the stability of models deployed on Microsoft Foundry. Requirements Before we open the terminal, let's make sure you have the necessary accounts and environments ready. Since we are bridging a local CLI with an enterprise cloud setup, having these credentials handy now will save you time later. Azure Subscription with Microsoft Foundry Setup - This is the most critical piece. You need an active Azure subscription where the Microsoft Foundry environment is initialized. Ensure that you have deployed the Claude model you intend to use and that the deployment status is active. You will need the specific endpoint URL and the associated API keys from this deployment to configure the connection. An Anthropic User Account - Even though the compute is happening on Azure, the interface requires an Anthropic account. You will need this to authenticate your session and manage your user profile settings within the Claude Code ecosystem. Claude Code Client on macOS - We will be running the commands locally, so you need the Claude Code CLI installed on your MacBook. Step 1: Install Claude Code on macOS The recommended installation method is via Homebrew or Curl, which sets it up for terminal access ("OS level"). Option A: Homebrew (Recommended) brew install --cask claude-code Option B: Curl curl -fsSL https://claude.ai/install.sh | bash Verify Installation: Run claude --version. Step 2: Set Up Microsoft Foundry to deploy Claude model Navigate to your Microsoft Foundry portal, and find the Claude model catalog, and deploy the selected Claude model. [Microsoft Foundry > My Assets > Models + endpoints > + Deploy Model > Deploy Base model > Search for "Claude"] In your Model Deployment dashboard, go to the deployed Claude Models and get the "Endpoints and keys". Store it somewhere safe, because we will need them to configure Claude Code later on. Configure Environment Variables in MacOS terminal: Now we need to tell your local Claude Code client to route requests through Microsoft Foundry instead of the default Anthropic endpoints. This is handled by setting specific environment variables that act as a bridge between your local machine and your Azure resources. You could run these commands manually every time you open a terminal, but it is much more efficient to save them permanently in your shell profile. For most modern macOS users, this file is .zshrc. Open your terminal and add the following lines to your profile, making sure to replace the placeholder text with your actual Azure credentials: export CLAUDE_CODE_USE_FOUNDRY=1 export ANTHROPIC_FOUNDRY_API_KEY="your-azure-api-key" export ANTHROPIC_FOUNDRY_RESOURCE="your-resource-name" # Specify the deployment name for Opus export CLAUDE_CODE_MODEL="your-opus-deployment-name" Once you have added these variables, you need to reload your shell configuration for the changes to take effect. Run the source command below to update your current session, and then verify the setup by launching Claude: source ~/.zshrc claude If everything is configured correctly, the Claude CLI will initialize using your Microsoft Foundry deployment as the backend. Once you execute the claude command, the CLI will prompt you to choose an authentication method. Select Option 2 (Antrophic Console account) to proceed. This action triggers your default web browser and redirects you to the Claude Console. Simply sign in using your standard Anthropic account credentials. After you have successfully signed in, you will be presented with a permissions screen. Click the Authorize button to link your web session back to your local terminal. Return to your terminal window, and you should see a notification confirming that the login process is complete. Press Enter to finalize the setup. You are now fully connected. You can start using Claude Code locally, powered entirely by the model deployment running in your Microsoft Foundry environment. Conclusion Setting up this environment might seem like a heavy lift just to run a CLI tool, but the payoff is significant. You now have a workflow that combines the immediate feedback of local development with the security and infrastructure benefits of Microsoft Foundry. One of the most practical upgrades is the removal of standard usage caps. You are no longer limited to the 5-hour API call limits, which gives you the freedom to iterate, test, and debug for as long as your project requires without hitting a wall. By bridging your local macOS terminal to Azure, you are no longer just hitting an API endpoint. You are leveraging a managed, compliance-ready environment that scales with your needs. The best part is that now the configuration is locked in, you don't need to think about the plumbing again. You can focus entirely on coding, knowing that the reliability of an enterprise platform is running quietly in the background supporting every command.Agents League: Build, Learn, and Level Up Your AI Skills
We're inviting the next generation of developers to join Agents League, running February 16-27. It's a two-week challenge where you'll build AI agents using production-ready tools, learn from live coding sessions, and get feedback directly from Microsoft product teams. We've put together starter kits for each track to help you get up and running quickly that also includes requirements and guidelines. Whether you want to explore what GitHub Copilot can do beyond autocomplete, build reasoning agents on Microsoft Foundry, or create enterprise integrations for Microsoft 365 Copilot, we have a track for you. Important: Register first to be eligible for prizes and your digital badge. Without registration, you won't qualify for awards or receive a badge when you submit. What Is Agents League? It's a 2-week competition where you learn by doing: 📽️ Live coding battles – Watch experts compete in real-time and explain their thinking 💻 Build at your pace – Two weeks to work on your project 💬 Get help on Discord – AMAs, community support, and a friendly crowd to cheer you on 🏆 Win prizes – $500 per track, GitHub Copilot Pro subscriptions, and digital badges for everyone who submits The Three Tracks 🎨 Creative Apps — Build with GitHub Copilot (Chat, CLI, or SDK) 🧠 Reasoning Agents — Build with Microsoft Foundry 💼 Enterprise Agents — Build with M365 Agents Toolkit (or Copilot Studio) More details on each track below, or jump straight to the starter kits. The Schedule Agents League starts on February 16th and runs through February 27th. Within 2 weeks, we host live battles on Reactor and AMA sessions on Discord. Week 1: Live Battles (Feb 17-19) We're kicking off with live coding battles streamed on Microsoft Reactor. Watch experienced developers compete in real-time, explaining their approach and architectural decisions as they go. Tue Feb 17, 9 AM PT — 🎨 Creative Apps battle Wed Feb 18, 9 AM PT — 🧠 Reasoning Agents battle Thu Feb 19, 9 AM PT — 💼 Enterprise Agents battle All sessions are recorded, so you can watch on your own schedule. Week 2: Build + AMAs (Feb 24-26) This is your time to build and ask questions on Discord. The async format means you work when it suits you, evenings, weekends, whatever fits your schedule. We're also hosting AMAs on Discord where you can ask questions directly to Microsoft experts and product teams: Tue Feb 24, 9 AM PT — 🎨 Creative Apps AMA Wed Feb 25, 9 AM PT — 🧠 Reasoning Agents AMA Thu Feb 26, 9 AM PT — 💼 Enterprise Agents AMA Bring your questions, get help when you're stuck, and share what you're building with the community. Pick Your Track We've created a starter kit for each track with setup guides, project ideas, and example scenarios to help you get started quickly. 🎨 Creative Apps Tool: GitHub Copilot (Chat, CLI, or SDK) Build innovative, imaginative applications that showcase the potential of AI-assisted development. All application types are welcome, web apps, CLI tools, games, mobile apps, desktop applications, and more. The starter kit walks you through GitHub Copilot's different modes and provides prompting tips to get the best results.View the Creative Apps starter kit. 🧠 Reasoning Agents Tool: Microsoft Foundry (UI or SDK) and/or Microsoft Agent Framework Build a multi-agent system that leverages advanced reasoning capabilities to solve complex problems. This track focuses on agents that can plan, reason through multi-step problems, and collaborate. The starter kit includes architecture patterns, reasoning strategies (planner-executor, critic/verifier, self-reflection), and integration guides for tools and MCP servers. View the Reasoning Agents starter kit. 💼 Enterprise Agents Tool: M365 Agents Toolkit or Copilot Studio Create intelligent agents that extend Microsoft 365 Copilot to address real-world enterprise scenarios. Your agent must work on Microsoft 365 Copilot Chat. Bonus points for: MCP server integration, OAuth security, Adaptive Cards UI, connected agents (multi-agent architecture). View the Enterprise Agents starter kit. Prizes & Recognition To be eligible for prizes and your digital badge, you must register before submitting your project. Category Winners ($500 each): 🎨 Creative Apps winner 🧠 Reasoning Agents winner 💼 Enterprise Agents winner GitHub Copilot Pro subscriptions: Community Favorite (voted by participants on Discord) Product Team Picks (selected by Microsoft product teams) Everyone who registers and submits a project wins: A digital badge to showcase their participation. Beyond the prizes, every participant gets feedback from the teams who built these tools, a valuable opportunity to learn and improve your approach to AI agent development. Why This Matters AI development is where the opportunities are right now. Building with GitHub Copilot, Microsoft Foundry, and M365 Agents Toolkit gives you: A real project for your portfolio Hands-on experience with production-grade tools Connections with developers from around the world Whether you're looking for your first internship, exploring AI, or just want to build something cool, this is two weeks well spent. How to Get Started Register first — This is required to be eligible for prizes and to receive your digital badge. Without registration, your submission won't qualify for awards or a badge. Pick a track — Choose one track. Explore the starter kits to help you decide. Watch the battles — See how experienced developers approach these challenges. Great for learning even if you're still deciding whether to compete. Build your project — You have until Feb 27. Work on your own schedule. Submit via GitHub — Open an issue using the project submission template. Join us on Discord — Get help, share your progress, and vote for your favorite projects on Discord. Links Register: https://aka.ms/agentsleague/register Starter Kits: https://github.com/microsoft/agentsleague/starter-kits Discord: https://aka.ms/agentsleague/discord Live Battles: https://aka.ms/agentsleague/battles Submit Project: Project submission templateBuilding with Azure OpenAI Sora: A Complete Guide to AI Video Generation
In this comprehensive guide, we'll explore how to integrate both Sora 1 and Sora 2 models from Azure OpenAI Service into a production web application. We'll cover API integration, request body parameters, cost analysis, limitations, and the key differences between using Azure AI Foundry endpoints versus OpenAI's native API. Table of Contents Introduction to Sora Models Azure AI Foundry vs. OpenAI API Structure API Integration: Request Body Parameters Video Generation Modes Cost Analysis per Generation Technical Limitations & Constraints Resolution & Duration Support Implementation Best Practices Introduction to Sora Models Sora is OpenAI's groundbreaking text-to-video model that generates realistic videos from natural language descriptions. Azure AI Foundry provides access to two versions: Sora 1: The original model focused primarily on text-to-video generation with extensive resolution options (480p to 1080p) and flexible duration (1-20 seconds) Sora 2: The enhanced version with native audio generation, multiple generation modes (text-to-video, image-to-video, video-to-video remix), but more constrained resolution options (720p only in public preview) Azure AI Foundry vs. OpenAI API Structure Key Architectural Differences Sora 1 uses Azure's traditional deployment-based API structure: Endpoint Pattern: https://{resource-name}.openai.azure.com/openai/deployments/{deployment-name}/... Parameters: Uses Azure-specific naming like n_seconds, n_variants, separate width/height fields Job Management: Uses /jobs/{id} for status polling Content Download: Uses /video/generations/{generation_id}/content/video Sora 2 adapts OpenAI's v1 API format while still being hosted on Azure: Endpoint Pattern: https://{resource-name}.openai.azure.com/openai/deployments/{deployment-name}/videos Parameters: Uses OpenAI-style naming like seconds (string), size (combined dimension string like "1280x720") Job Management: Uses /videos/{video_id} for status polling Content Download: Uses /videos/{video_id}/content Why This Matters? This architectural difference requires conditional request formatting in your code: const isSora2 = deployment.toLowerCase().includes('sora-2'); if (isSora2) { requestBody = { model: deployment, prompt, size: `${width}x${height}`, // Combined format seconds: duration.toString(), // String type }; } else { requestBody = { model: deployment, prompt, height, // Separate dimensions width, n_seconds: duration.toString(), // Azure naming n_variants: variants, }; } API Integration: Request Body Parameters Sora 1 API Parameters Standard Text-to-Video Request: { "model": "sora-1", "prompt": "Wide shot of a child flying a red kite in a grassy park, golden hour sunlight, camera slowly pans upward.", "height": "720", "width": "1280", "n_seconds": "12", "n_variants": "2" } Parameter Details: model (String, Required): Your Azure deployment name prompt (String, Required): Natural language description of the video (max 32000 chars) height (String, Required): Video height in pixels width (String, Required): Video width in pixels n_seconds (String, Required): Duration (1-20 seconds) n_variants (String, Optional): Number of variations to generate (1-4, constrained by resolution) Sora 2 API Parameters Text-to-Video Request: { "model": "sora-2", "prompt": "A serene mountain landscape with cascading waterfalls, cinematic drone shot", "size": "1280x720", "seconds": "12" } Image-to-Video Request (uses FormData): const formData = new FormData(); formData.append('model', 'sora-2'); formData.append('prompt', 'Animate this image with gentle wind movement'); formData.append('size', '1280x720'); formData.append('seconds', '8'); formData.append('input_reference', imageFile); // JPEG/PNG/WebP Video-to-Video Remix Request: Endpoint: POST .../videos/{video_id}/remix Body: Only { "prompt": "your new description" } The original video's structure, motion, and framing are reused while applying the new prompt Parameter Details: model (String, Optional): Your deployment name prompt (String, Required): Video description size (String, Optional): Either "720x1280" or "1280x720" (defaults to "720x1280") seconds (String, Optional): "4", "8", or "12" (defaults to "4") input_reference (File, Optional): Reference image for image-to-video mode remix_video_id (String, URL parameter): ID of video to remix Video Generation Modes 1. Text-to-Video (Both Models) The foundational mode where you provide a text prompt describing the desired video. Implementation: const response = await fetch(endpoint, { method: 'POST', headers: { 'Content-Type': 'application/json', 'api-key': apiKey, }, body: JSON.stringify({ model: deployment, prompt: "A train journey through mountains with dramatic lighting", size: "1280x720", seconds: "12", }), }); Best Practices: Include shot type (wide, close-up, aerial) Describe subject, action, and environment Specify lighting conditions (golden hour, dramatic, soft) Add camera movement if desired (pans, tilts, tracking shots) 2. Image-to-Video (Sora 2 Only) Generate a video anchored to or starting from a reference image. Key Requirements: Supported formats: JPEG, PNG, WebP Image dimensions must exactly match the selected video resolution Our implementation automatically resizes uploaded images to match Implementation Detail: // Resize image to match video dimensions const targetWidth = parseInt(width); const targetHeight = parseInt(height); const resizedImage = await resizeImage(inputReference, targetWidth, targetHeight); // Send as multipart/form-data formData.append('input_reference', resizedImage); 3. Video-to-Video Remix (Sora 2 Only) Create variations of existing videos while preserving their structure and motion. Use Cases: Change weather conditions in the same scene Modify time of day while keeping camera movement Swap subjects while maintaining composition Adjust artistic style or color grading Endpoint Structure: POST {base_url}/videos/{original_video_id}/remix?api-version=2024-08-01-preview Implementation: let requestEndpoint = endpoint; if (isSora2 && remixVideoId) { const [baseUrl, queryParams] = endpoint.split('?'); const root = baseUrl.replace(/\/videos$/, ''); requestEndpoint = `${root}/videos/${remixVideoId}/remix${queryParams ? '?' + queryParams : ''}`; } Cost Analysis per Generation Sora 1 Pricing Model Base Rate: ~$0.05 per second per variant at 720p Resolution Scaling: Cost scales linearly with pixel count Formula: const basePrice = 0.05; const basePixels = 1280 * 720; // Reference resolution const currentPixels = width * height; const resolutionMultiplier = currentPixels / basePixels; const totalCost = basePrice * duration * variants * resolutionMultiplier; Examples: 720p (1280×720), 12 seconds, 1 variant: $0.60 1080p (1920×1080), 12 seconds, 1 variant: $1.35 720p, 12 seconds, 2 variants: $1.20 Sora 2 Pricing Model Flat Rate: $0.10 per second per variant (no resolution scaling in public preview) Formula: const totalCost = 0.10 * duration * variants; Examples: 720p (1280×720), 4 seconds: $0.40 720p (1280×720), 12 seconds: $1.20 720p (720×1280), 8 seconds: $0.80 Note: Since Sora 2 currently only supports 720p in public preview, resolution doesn't affect cost, only duration matters. Cost Comparison Scenario Sora 1 (720p) Sora 2 (720p) Winner 4s video $0.20 $0.40 Sora 1 12s video $0.60 $1.20 Sora 1 12s + audio N/A (no audio) $1.20 Sora 2 (unique) Image-to-video N/A $0.40-$1.20 Sora 2 (unique) Recommendation: Use Sora 1 for cost-effective silent videos at various resolutions. Use Sora 2 when you need audio, image/video inputs, or remix capabilities. Technical Limitations & Constraints Sora 1 Limitations Resolution Options: 9 supported resolutions from 480×480 to 1920×1080 Includes square, portrait, and landscape formats Full list: 480×480, 480×854, 854×480, 720×720, 720×1280, 1280×720, 1080×1080, 1080×1920, 1920×1080 Duration: Flexible: 1 to 20 seconds Any integer value within range Variants: Depends on resolution: 1080p: Variants disabled (n_variants must be 1) 720p: Max 2 variants Other resolutions: Max 4 variants Concurrent Jobs: Maximum 2 jobs running simultaneously Job Expiration: Videos expire 24 hours after generation Audio: No audio generation (silent videos only) Sora 2 Limitations Resolution Options (Public Preview): Only 2 options: 720×1280 (portrait) or 1280×720 (landscape) No square formats No 1080p support in current preview Duration: Fixed options only: 4, 8, or 12 seconds No custom durations Defaults to 4 seconds if not specified Variants: Not prominently supported in current API documentation Focus is on single high-quality generations with audio Concurrent Jobs: Maximum 2 jobs (same as Sora 1) Job Expiration: 24 hours (same as Sora 1) Audio: Native audio generation included (dialogue, sound effects, ambience) Shared Constraints Concurrent Processing: Both models enforce a limit of 2 concurrent video jobs per Azure resource. You must wait for one job to complete before starting a third. Job Lifecycle: queued → preprocessing → processing/running → completed Download Window: Videos are available for 24 hours after completion. After expiration, you must regenerate the video. Generation Time: Typical: 1-5 minutes depending on resolution, duration, and API load Can occasionally take longer during high demand Resolution & Duration Support Matrix Sora 1 Support Matrix Resolution Aspect Ratio Max Variants Duration Range Use Case 480×480 Square 4 1-20s Social thumbnails 480×854 Portrait 4 1-20s Mobile stories 854×480 Landscape 4 1-20s Quick previews 720×720 Square 4 1-20s Instagram posts 720×1280 Portrait 2 1-20s TikTok/Reels 1280×720 Landscape 2 1-20s YouTube shorts 1080×1080 Square 1 1-20s Premium social 1080×1920 Portrait 1 1-20s Premium vertical 1920×1080 Landscape 1 1-20s Full HD content Sora 2 Support Matrix Resolution Aspect Ratio Duration Options Audio Generation Modes 720×1280 Portrait 4s, 8s, 12s ✅ Yes Text, Image, Video Remix 1280×720 Landscape 4s, 8s, 12s ✅ Yes Text, Image, Video Remix Note: Sora 2's limited resolution options in public preview are expected to expand in future releases. Implementation Best Practices 1. Job Status Polling Strategy Implement adaptive backoff to avoid overwhelming the API: const maxAttempts = 180; // 15 minutes max let attempts = 0; const baseDelayMs = 3000; // Start with 3 seconds while (attempts < maxAttempts) { const response = await fetch(statusUrl, { headers: { 'api-key': apiKey }, }); if (response.status === 404) { // Job not ready yet, wait longer const delayMs = Math.min(15000, baseDelayMs + attempts * 1000); await new Promise(r => setTimeout(r, delayMs)); attempts++; continue; } const job = await response.json(); // Check completion (different status values for Sora 1 vs 2) const isCompleted = isSora2 ? job.status === 'completed' : job.status === 'succeeded'; if (isCompleted) break; // Adaptive backoff const delayMs = Math.min(15000, baseDelayMs + attempts * 1000); await new Promise(r => setTimeout(r, delayMs)); attempts++; } 2. Handling Different Response Structures Sora 1 Video Download: const generations = Array.isArray(job.generations) ? job.generations : []; const genId = generations[0]?.id; const videoUrl = `${root}/${genId}/content/video`; Sora 2 Video Download: const videoUrl = `${root}/videos/${jobId}/content`; 3. Error Handling try { const response = await fetch(endpoint, fetchOptions); if (!response.ok) { const error = await response.text(); throw new Error(`Video generation failed: ${error}`); } // ... handle successful response } catch (error) { console.error('[VideoGen] Error:', error); // Implement retry logic or user notification } 4. Image Preprocessing for Image-to-Video Always resize images to match the target video resolution: async function resizeImage(file: File, targetWidth: number, targetHeight: number): Promise<File> { return new Promise((resolve, reject) => { const img = new Image(); const canvas = document.createElement('canvas'); const ctx = canvas.getContext('2d'); img.onload = () => { canvas.width = targetWidth; canvas.height = targetHeight; ctx.drawImage(img, 0, 0, targetWidth, targetHeight); canvas.toBlob((blob) => { if (blob) { const resizedFile = new File([blob], file.name, { type: file.type }); resolve(resizedFile); } else { reject(new Error('Failed to create resized image blob')); } }, file.type); }; img.onerror = () => reject(new Error('Failed to load image')); img.src = URL.createObjectURL(file); }); } 5. Cost Tracking Implement cost estimation before generation and tracking after: // Pre-generation estimate const estimatedCost = calculateCost(width, height, duration, variants, soraVersion); // Save generation record await saveGenerationRecord({ prompt, soraModel: soraVersion, duration: parseInt(duration), resolution: `${width}x${height}`, variants: parseInt(variants), generationMode: mode, estimatedCost, status: 'queued', jobId: job.id, }); // Update after completion await updateGenerationStatus(jobId, 'completed', { videoId: finalVideoId }); 6. Progressive User Feedback Provide detailed status updates during the generation process: const statusMessages: Record<string, string> = { 'preprocessing': 'Preprocessing your request...', 'running': 'Generating video...', 'processing': 'Processing video...', 'queued': 'Job queued...', 'in_progress': 'Generating video...', }; onProgress?.(statusMessages[job.status] || `Status: ${job.status}`); Conclusion Building with Azure OpenAI's Sora models requires understanding the nuanced differences between Sora 1 and Sora 2, both in API structure and capabilities. Key takeaways: Choose the right model: Sora 1 for resolution flexibility and cost-effectiveness; Sora 2 for audio, image inputs, and remix capabilities Handle API differences: Implement conditional logic for parameter formatting and status polling based on model version Respect limitations: Plan around concurrent job limits, resolution constraints, and 24-hour expiration windows Optimize costs: Calculate estimates upfront and track actual usage for better budget management Provide great UX: Implement adaptive polling, progressive status updates, and clear error messages The future of AI video generation is exciting, and Azure AI Foundry provides production-ready access to these powerful models. As Sora 2 matures and limitations are lifted (especially resolution options), we'll see even more creative applications emerge. Resources: Azure AI Foundry Sora Documentation OpenAI Sora API Reference Azure OpenAI Service Pricing This blog post is based on real-world implementation experience building LemonGrab, my AI video generation platform that integrates both Sora 1 and Sora 2 through Azure AI Foundry. The code examples are extracted from production usage.AI Didn’t Break Your Production — Your Architecture Did
Most AI systems don’t fail in the lab. They fail the moment production touches them. I’m Hazem Ali — Microsoft AI MVP, Principal AI & ML Engineer / Architect, and Founder & CEO of Skytells. With a strong foundation in AI and deep learning from low-level fundamentals to production-scale, backed by rigorous cybersecurity and software engineering expertise, I design and deliver enterprise AI systems end-to-end. I often speak about what happens after the pilot goes live: real users arrive, data drifts, security constraints tighten, and incidents force your architecture to prove it can survive. My focus is building production AI with a security-first mindset: identity boundaries, enforceable governance, incident-ready operations, and reliability at scale. My mission is simple: Architect and engineer secure AI systems that operate safely, predictably, and at scale in production. And here’s the hard truth: AI initiatives rarely fail because the model is weak. They fail because the surrounding architecture was never engineered for production reality. - Hazem Ali You see this clearly when teams bolt AI onto an existing platform. In Azure-based environments, the foundation can be solid—identity, networking, governance, logging, policy enforcement, and scale primitives. But that doesn’t make the AI layer production-grade by default. It becomes production-grade only when the AI runtime is engineered like a first-class subsystem with explicit boundaries, control points, and designed failure behavior. A quick moment from the field I still remember one rollout that looked perfect on paper. Latency was fine. Error rate was low. Dashboards were green. Everyone was relaxed. Then a single workflow started creating the wrong tickets, not failing or crashing. It was confidently doing the wrong thing at scale. It took hours before anyone noticed, because nothing was broken in the traditional sense. When we finally traced it, the model was not the root cause. The system had no real gates, no replayable trail, and tool execution was too permissive. The architecture made it easy for a small mistake to become a widespread mess. That is the gap I’m talking about in this article. Production Failure Taxonomy This is the part most teams skip because it is not exciting, and it is not easy to measure in a demo. When AI fails in production, the postmortem rarely says the model was bad. It almost always points to missing boundaries, over-privileged execution, or decisions nobody can trace. So if your AI can take actions, you are no longer shipping a chat feature. You are operating a runtime that can change state across real systems, that means reliability is not just uptime. It is the ability to limit blast radius, reproduce decisions, and stop or degrade safely when uncertainty or risk spikes. You can usually tell early whether an AI initiative will survive production. Not because the model is weak, but because the failure mode is already baked into the architecture. Here are the ones I see most often. 1. Healthy systems that are confidently wrong Uptime looks perfect. Latency is fine. And the output is wrong. This is dangerous because nothing alerts until real damage shows up. 2. The agent ends up with more authority than the user The user asks a question. The agent has tools and credentials. Now it can do things the user never should have been able to do in that moment. 3. Each action is allowed, but the chain is not Read data, create ticket, send message. All approved individually. Put together, it becomes a capability nobody reviewed. 4. Retrieval becomes the attack path Most teams worry about prompt injection. Fair. But a poisoned or stale retrieval layer can be worse, because it feeds the model the wrong truth. 5. Tool calls turn mistakes into incidents The moment AI can change state—config, permissions, emails, payments, or data—a mistake is no longer a bad answer. It is an incident. 6. Retries duplicate side effects Timeouts happen. Retries happen. If your tool calls are not safe to repeat, you will create duplicate tickets, refunds, emails, or deletes. Next, let’s talk about what changes when you inject probabilistic behavior into a deterministic platform. In the Field: Building and Sharing Real-World AI In December 2025, I had the chance to speak and engage with builders across multiple AI and technology events, sharing what I consider the most valuable part of the journey: the engineering details that show up when AI meets production reality. This photo captures one of those moments: real conversations with engineers, architects, and decision-makers about what it truly takes to ship production-grade AI. During my session, Designing Scalable and Secure Architecture at the Enterprise Scale I walked through the ideas in this article live on stage then went deeper into the engineering reality behind them: from zero-trust boundaries and runtime policy enforcement to observability, traceability, and safe failure design, The goal wasn’t to talk about “AI capability,” but to show how to build AI systems that operate safely and predictably at scale in production. Deterministic platforms, probabilistic behavior Most production platforms are built for deterministic behavior: defined contracts, predictable services, stable outputs. AI changes the physics. You introduce probabilistic behavior into deterministic pipelines and your failure modes multiply. An AI system can be confidently wrong while still looking “healthy” through basic uptime dashboards. That’s why reliability in production AI is rarely about “better prompts” or “higher model accuracy.” It’s about engineering the right control points: identity boundaries, governance enforcement, behavioral observability, and safe degradation. In other words: the model is only one component. The system is the product. Production AI Control Plane Here’s the thing. Once you inject probabilistic behavior into a deterministic platform, you need more than prompts and endpoints. You need a control plane. Not a fancy framework. Just a clear place in the runtime where decisions get bounded, actions get authorized, and behavior becomes explainable when something goes wrong. This is the simplest shape I have seen work in real enterprise systems. The control plane components Orchestrator Owns the workflow. Decides what happens next, and when the system should stop. Retrieval Brings in context, but only from sources you trust and can explain later. Prompt assembly Builds the final input to the model, including constraints, policy signals, and tool schemas. Model call Generates the plan or the response. It should never be trusted to execute directly. Policy Enforcement Point The gate before any high impact step. It answers: is this allowed, under these conditions, with these constraints. Tool Gateway The firewall for actions. Scopes every operation, validates inputs, rate-limits, and blocks unsafe calls. Audit log and trace store A replayable chain for every request. If you cannot replay it, you cannot debug it. Risk engine Detects prompt injection signals, anomalous sessions, uncertainty spikes, and switches the runtime into safer modes. Approval flow For the few actions that should never be automatic. It is the line between assistance and damage. If you take one idea from this section, let it be this. The model is not where you enforce safety. Safety lives in the control plane. Next, let’s talk about the most common mistake teams make right after they build the happy-path pipeline. Treating AI like a feature. The common architectural trap: treating AI like a feature Many teams ship AI like a feature: prompt → model → response. That structure demos well. In production, it collapses the moment AI output influences anything stateful tickets, approvals, customer messaging, remediation actions, or security decisions. At that point, you’re not “adding AI.” You’re operating a semi-autonomous runtime. The engineering questions become non-negotiable: Can we explain why the system responded this way? Can we bound what it’s allowed to do? Can we contain impact when it’s wrong? Can we recover without human panic? If those answers aren’t designed into the architecture, production becomes a roulette wheel. Governance is not a document It’s a runtime enforcement capability Most governance programs fail because they’re implemented as late-stage checklists. In production, governance must live inside the execution path as an enforceable mechanism, A Policy Enforcement Point (PEP) that evaluates every high-impact step before it happens. At the moment of execution, your runtime must answer a strict chain of authorization questions: 1. What tools is this agent attempting to call? Every tool invocation is a privilege boundary. Your runtime must identify the tool, the operation, and the intended side effect (read vs write, safe vs state-changing). 2. Does the tool have the right permissions to run for this agent? Even before user context, the tool itself must be runnable by the agent’s workload identity (service principal / managed identity / workload credentials). If the agent identity can’t execute the tool, the call is denied period. 3. If the tool can run, is the agent permitted to use it for this user? This is the missing piece in most systems: delegation. The agent might be able to run the tool in general, but not on behalf of this user, in this tenant, in this environment, for this task category. This is where you enforce: user role / entitlement tenant boundaries environment (prod vs staging) session risk level (normal vs suspicious) 4. If yes, which tasks/operations are permitted? Tools are too broad. Permissions must be operation-scoped. Not “Jira tool allowed.” But “Jira: create ticket only, no delete, no project-admin actions.” Not “Database tool allowed.” But “DB: read-only, specific schema, specific columns, row-level filters.” This is ABAC/RBAC + capability-based execution. 5. What data scope is allowed? Even a permitted tool operation must be constrained by data classification and scope: public vs internal vs confidential vs PII row/column filters time-bounded access purpose limitation (“only for incident triage”) If the system can’t express data scope at runtime, it can’t claim governance. 6. What operations require human approval? Some actions are inherently high risk: payments/refunds changing production configs emailing customers deleting data executing scripts The policy should return “REQUIRE_APPROVAL” with clear obligations (what must be reviewed, what evidence is required, who can approve). 7. What actions are forbidden under certain risk conditions? Risk-aware policy is the difference between governance and theater. Examples: If prompt injection signals are high → disable tool execution If session is anomalous → downgrade to read-only mode If data is PII + user not entitled → deny and redact If environment is prod + request is destructive → block regardless of model confidence The key engineering takeaway Governance works only when it’s enforceable, runtime-evaluated, and capability-scoped: Agent identity answers: “Can it run at all?” Delegation answers: “Can it run for this user?” Capabilities answer: “Which operations exactly?” Data scope answers: “How much and what kind of data?” Risk gates + approvals answer: “When must it stop or escalate?” If policy can’t be enforced at runtime, it isn’t governance. It’s optimism. Safe Execution Patterns Policy answers whether something is allowed. Safe execution answers what happens when things get messy. Because they will, Models time out, Retries happen, Inputs are adversarial. People ask for the wrong thing. Agents misunderstand. And when tools can change state, small mistakes turn into real incidents. These patterns are what keep the system stable when the world is not. 👈 Two-phase execution Do not execute directly from a model output. First phase: propose a plan and a dry-run summary of what will change. Second phase: execute only after policy gates pass, and approval is collected if required. Idempotency for every write If a tool call can create, refund, email, delete, or deploy, it must be safe to retry. Every write gets an idempotency key, and the gateway rejects duplicates. This one change prevents a huge class of production pain. Default to read-only when risk rises When injection signals spike, when the session looks anomalous, when retrieval looks suspicious, the system should not keep acting. It should downgrade. Retrieve, explain, and ask. No tool execution. Scope permissions to operations, not tools Tools are too broad. Do not allow Jira. Allow create ticket in these projects, with these fields. Do not allow database access. Allow read-only on this schema, with row and column filters. Rate limits and blast radius caps Agents should have a hard ceiling. Max tool calls per request. Max writes per session. Max affected entities. If the cap is hit, stop and escalate. A kill switch that actually works You need a way to disable tool execution across the fleet in one move. When an incident happens, you do not want to redeploy code. You want to stop the bleeding. If you build these in early, you stop relying on luck. You make failure boring, contained, and recoverable. Think for scale, in the Era of AI for AI I want to zoom out for a second, because this is the shift most teams still design around. We are not just adding AI to a product. We are entering a phase where parts of the system can maintain and improve themselves. Not in a magical way. In a practical, engineering way. A self-improving system is one that can watch what is happening in production, spot a class of problems, propose changes, test them, and ship them safely, while leaving a clear trail behind it. It can improve code paths, adjust prompts, refine retrieval rules, update tests, and tighten policies. Over time, the system becomes less dependent on hero debugging at 2 a.m. What makes this real is the loop, not the model. Signals come in from logs, traces, incidents, drift metrics, and quality checks. The system turns those signals into a scoped plan. Then it passes through gates: policy and permissions, safe scope, testing, and controlled rollout. If something looks wrong, it stops, downgrades to read-only, or asks for approval. This is why scale changes. In the old world, scale meant more users and more traffic. In the AI for AI world, scale also means more autonomy. One request can trigger many tool calls. One workflow can spawn sub-agents. One bad signal can cause retries and cascades. So the question is not only can your system handle load. The question is can your system handle multiplication without losing control. If you want self-improving behavior, you need three things to be true: The system is allowed to change only what it can prove is safe to change. Every change is testable and reversible. Every action is traceable, so you can replay why it happened. When those conditions exist, self-improvement becomes an advantage. When they do not, self-improvement becomes automated risk. And this leads straight into governance, because in this era governance is not a document. It is the gate that decides what the system is allowed to improve, and under which conditions. Observability: uptime isn’t enough — you need traceability and causality Traditional observability answers: Is the service up. Is it fast. Is it erroring. That is table stakes. Production AI needs a deeper truth: why did it do that. Because the system can look perfectly healthy while still making the wrong decision. Latency is fine. Error rate is fine. Dashboards are green. And the output is still harmful. To debug that kind of failure, you need causality you can replay and audit: Input → context retrieval → prompt assembly → model response → tool invocation → final outcome Without this chain, incident response becomes guesswork. People argue about prompts, blame the model, and ship small patches that do not address the real cause. Then the same issue comes back under a different prompt, a different document, or a slightly different user context. The practical goal is simple. Every high-impact action should have a story you can reconstruct later. What did the system see. What did it pull. What did it decide. What did it touch. And which policy allowed it. When you have that, you stop chasing symptoms. You can fix the actual failure point, and you can detect drift before users do. RAG Governance and Data Provenance Most teams treat retrieval as a quality feature. In production, retrieval is a security boundary. Because the moment a document enters the context window, it becomes part of the system’s brain for that request. If retrieval pulls the wrong thing, the model can behave perfectly and still lead you to a bad outcome. I learned this the hard way, I have seen systems where the model was not the problem at all. The problem was a single stale runbook that looked official, ranked high, and quietly took over the decision. Everything downstream was clean. The agent followed instructions, called the right tools, and still caused damage because the truth it was given was wrong. I keep repeating one line in reviews, and I mean it every time: Retrieval is where truth enters the system. If you do not control that, you are not governing anything. - Hazem Ali So what makes retrieval safe enough for enterprise use? Provenance on every chunk Every retrieved snippet needs a label you can defend later: source, owner, timestamp, and classification. If you cannot answer where it came from, you cannot trust it for actions. Staleness budgets Old truth is a real risk. A runbook from last quarter can be more dangerous than no runbook at all. If content is older than a threshold, the system should say it is old, and either confirm or downgrade to read-only. No silent reliance. Allowlisted sources per task Not all sources are valid for all jobs. Incident response might allow internal runbooks. Customer messaging might require approved templates only. Make this explicit. Retrieval should not behave like a free-for-all search engine. Scope and redaction before the model sees it Row and column limits, PII filtering, secret stripping, tenant boundaries. Do it before prompt assembly, not after the model has already seen the data. Citation requirement for high-impact steps If the system is about to take a high-impact action, it should be able to point to the sources that justified it. If it cannot, it should stop and ask. That one rule prevents a lot of confident nonsense. Monitor retrieval like a production dependency Track which sources are being used, which ones cause incidents, and where drift is coming from. Retrieval quality is not static. Content changes. Permissions change. Rankings shift. Behavior follows. When you treat retrieval as governance, the system stops absorbing random truth. It consumes controlled truth, with ownership, freshness, and scope. That is what production needs. Security: API keys aren’t a strategy when agents can act The highest-impact AI incidents are usually not model hacks. They are architectural failures: over-privileged identities, blurred trust boundaries, unbounded tool access, and unsafe retrieval paths. Once an agent can call tools that mutate state, treat it like a privileged service, not a chatbot. Least privilege by default Explicit authorization boundaries Auditable actions Containment-first design Clear separation between user intent and system authority This is how you prevent a prompt injection from turning into a system-level breach. If you want the deeper blueprint and the concrete patterns for securing agents in practice, I wrote a full breakdown here: Zero-Trust Agent Architecture: How to Actually Secure Your Agents What “production-ready AI” actually means Production-ready AI is not defined by a benchmark score. It’s defined by survivability under uncertainty. A production-grade AI system can: Explain itself with traceability. Enforce policy at runtime. Contain blast radius when wrong. Degrade safely under uncertainty. Recover with clear operational playbooks. If your system can’t answer “how does it fail?” you don’t have production AI yet.. You have a prototype with unmanaged risk. How Azure helps you engineer production-grade AI Azure doesn’t “solve” production-ready AI by itself, it gives you the primitives to engineer it correctly. The difference between a prototype and a survivable system is whether you translate those primitives into runtime control points: identity, policy enforcement, telemetry, and containment. 1. Identity-first execution (kill credential sprawl, shrink blast radius) A production AI runtime should not run on shared API keys or long-lived secrets. In Azure environments, the most important mindset shift is: every agent/workflow must have an identity and that identity must be scoped. Guidance Give each agent/orchestrator a dedicated identity (least privilege by default). Separate identities by environment (prod vs staging) and by capability (read vs write). Treat tool invocation as a privileged service call, never “just a function.” Why this matters If an agent is compromised (or tricked via prompt injection), identity boundaries decide whether it can read one table or take down a whole environment. 2. Policy as enforcement (move governance into the execution path) Your article’s core idea governance is runtime enforcement maps perfectly to Azure’s broader governance philosophy: policies must be enforceable, not advisory. Guidance Create an explicit Policy Enforcement Point (PEP) in your agent runtime. Make the PEP decision mandatory before executing any tool call or data access. Use “allow + obligations” patterns: allow only with constraints (redaction, read-only mode, rate limits, approval gates, extra logging). Why this matters Governance fails when it’s a document. It works when it’s compiled into runtime decisions. 3. Observability that explains behavior Azure’s telemetry stack is valuable because it’s designed for distributed systems: correlation, tracing, and unified logs. Production AI needs the same plus decision traceability. Guidance Emit a trace for every request across: retrieval → prompt assembly → model call → tool calls → outcome. Log policy decisions (allow/deny/require approval) with policy version + obligations applied. Capture “why” signals: risk score, classifier outputs, injection signals, uncertainty indicators. Why this matters When incidents happen, you don’t just debug latency — you debug behavior. Without causality, you can’t root-cause drift or containment failures. 4. Zero-trust boundaries for tools and data Azure environments tend to be strong at network segmentation and access control. That foundation is exactly what AI systems need because AI introduces adversarial inputs by default. Guidance Put a Tool Gateway in front of tools (Jira, email, payments, infra) and enforce scopes there. Restrict data access by classification (PII/secret zones) and enforce row/column constraints. Degrade safely: if risk is high, drop to read-only, disable tools, or require approval. Why this matters Prompt injection doesn’t become catastrophic when your system has hard boundaries and graceful failure modes. 5. Practical “production-ready” checklist (Azure-aligned, engineering-first) If you want a concrete way to apply this: Identity: every runtime has a scoped identity; no shared secrets PEP: every tool/data action is gated by policy, with obligations Traceability: full chain captured and correlated end-to-end Containment: safe degradation + approval gates for high-risk actions Auditability: policy versions and decision logs are immutable and replayable Environment separation: prod ≠ staging identities, tools, and permissions Outcome This is how you turn “we integrated AI” into “we operate AI safely at scale.” Operating Production AI A lot of teams build the architecture and still struggle, because production is not a diagram. It is a living system. So here is the operating model I look for when I want to trust an AI runtime in production. The few SLOs that actually matter Trace completeness For high-impact requests, can we reconstruct the full chain every time, without missing steps. Policy coverage What percentage of tool calls and sensitive reads pass through the policy gate, with a recorded decision. Action correctness Not model accuracy. Real-world correctness. Did the system take the right action, on the right target, with the right scope. Time to contain When something goes wrong, how fast can we stop tool execution, downgrade to read-only, or isolate a capability. Drift detection time How quickly do we notice behavioral drift before users do. The runbooks you must have If you operate agents, you need simple playbooks for predictable bad days: Injection spike → safe mode, block tool execution, force approvals Retrieval poisoning suspicion → restrict sources, raise freshness requirements, require citations Retry storm → enforce idempotency, rate limits, and circuit breakers Tool gateway instability → fail closed for writes, degrade safely for reads Model outage → fall back to deterministic paths, templates, or human escalation Clear ownership Someone has to own the runtime, not just the prompts. Platform owns the gates, tool gateway, audit, and tracing Product owns workflows and user-facing behavior Security owns policy rules, high-risk approvals, and incident procedures When these pieces are real, production becomes manageable. When they are not, you rely on luck and hero debugging. The 60-second production readiness checklist If you want a fast sanity check, here it is. Every agent has an identity, scoped per environment No shared API keys for privileged actions Every tool call goes through a policy gate with a logged decision Permissions are scoped to operations, not whole tools Writes are idempotent, retries cannot duplicate side effects Tool gateway validates inputs, scopes data, and rate-limits actions There is a safe mode that disables tools under risk There is a kill switch that stops tool execution across the fleet Retrieval is allowlisted, provenance-tagged, and freshness-aware High-impact actions require citations or they stop and ask Audit logs are immutable enough to trust later Traces are replayable end-to-end for any incident If most of these are missing, you do not have production AI yet. You have a prototype with unmanaged risk. A quick note In Azure-based enterprises, you already have strong primitives that mirror the mindset production AI requires: identity-first access control (Microsoft Entra ID), secure workload authentication patterns (managed identities), and deep telemetry foundations (Azure Monitor / Application Insights). The key is translating that discipline into the AI runtime so governance, identity, and observability aren’t external add-ons, but part of how AI executes and acts. Closing Models will keep evolving. Tooling will keep improving. But enterprise AI success still comes down to systems engineering. If you’re building production AI today, what has been the hardest part in your environment: governance, observability, security boundaries, or operational reliability? If you’re dealing with deep technical challenges around production AI, agent security, RAG governance, or operational reliability, feel free to connect with me on LinkedIn. I’m open to technical discussions and architecture reviews. Thanks for reading. — Hazem AliUnleashing the Power of Model Context Protocol (MCP): A Game-Changer in AI Integration
Artificial Intelligence is evolving rapidly, and one of the most pressing challenges is enabling AI models to interact effectively with external tools, data sources, and APIs. The Model Context Protocol (MCP) solves this problem by acting as a bridge between AI models and external services, creating a standardized communication framework that enhances tool integration, accessibility, and AI reasoning capabilities. What is Model Context Protocol (MCP)? MCP is a protocol designed to enable AI models, such as Azure OpenAI models, to interact seamlessly with external tools and services. Think of MCP as a universal USB-C connector for AI, allowing language models to fetch information, interact with APIs, and execute tasks beyond their built-in knowledge. Key Features of MCP Standardized Communication – MCP provides a structured way for AI models to interact with various tools. Tool Access & Expansion – AI assistants can now utilize external tools for real-time insights. Secure & Scalable – Enables safe and scalable integration with enterprise applications. Multi-Modal Integration – Supports STDIO, SSE (Server-Sent Events), and WebSocket communication methods. MCP Architecture & How It Works MCP follows a client-server architecture that allows AI models to interact with external tools efficiently. Here’s how it works: Components of MCP MCP Host – The AI model (e.g., Azure OpenAI GPT) requesting data or actions. MCP Client – An intermediary service that forwards the AI model's requests to MCP servers. MCP Server – Lightweight applications that expose specific capabilities (APIs, databases, files, etc.). Data Sources – Various backend systems, including local storage, cloud databases, and external APIs. Data Flow in MCP The AI model sends a request (e.g., "fetch user profile data"). The MCP client forwards the request to the appropriate MCP server. The MCP server retrieves the required data from a database or API. The response is sent back to the AI model via the MCP client. Integrating MCP with Azure OpenAI Services Microsoft has integrated MCP with Azure OpenAI Services, allowing GPT models to interact with external services and fetch live data. This means AI models are no longer limited to static knowledge but can access real-time information. Benefits of Azure OpenAI Services + MCP Integration ✔ Real-time Data Fetching – AI assistants can retrieve fresh information from APIs, databases, and internal systems. ✔ Contextual AI Responses – Enhances AI responses by providing accurate, up-to-date information. ✔ Enterprise-Ready – Secure and scalable for business applications, including finance, healthcare, and retail. Hands-On Tools for MCP Implementation To implement MCP effectively, Microsoft provides two powerful tools: Semantic Workbench and AI Gateway. Microsoft Semantic Workbench A development environment for prototyping AI-powered assistants and integrating MCP-based functionalities. Features: Build and test multi-agent AI assistants. Configure settings and interactions between AI models and external tools. Supports GitHub Codespaces for cloud-based development. Explore Semantic Workbench Workbench interface examples Microsoft AI Gateway A plug-and-play interface that allows developers to experiment with MCP using Azure API Management. Features: Credential Manager – Securely handle API credentials. Live Experimentation – Test AI model interactions with external tools. Pre-built Labs – Hands-on learning for developers. Explore AI Gateway Setting Up MCP with Azure OpenAI Services Step 1: Create a Virtual Environment First, create a virtual environment using Python: python -m venv .venv Activate the environment: # Windows venv\Scripts\activate # MacOS/Linux source .venv/bin/activate Step 2: Install Required Libraries Create a requirements.txt file and add the following dependencies: langchain-mcp-adapters langgraph langchain-openai Then, install the required libraries: pip install -r requirements.txt Step 3: Set Up OpenAI API Key Ensure you have your OpenAI API key set up: # Windows setx OPENAI_API_KEY "<your_api_key> # MacOS/Linux export OPENAI_API_KEY=<your_api_key> Building an MCP Server This server performs basic mathematical operations like addition and multiplication. Create the Server File First, create a new Python file: touch math_server.py Then, implement the server: from mcp.server.fastmcp import FastMCP # Initialize the server mcp = FastMCP("Math") MCP.tool() def add(a: int, b: int) -> int: return a + b MCP.tool() def multiply(a: int, b: int) -> int: return a * b if __name__ == "__main__": mcp.run(transport="stdio") Your MCP server is now ready to run. Building an MCP Client This client connects to the MCP server and interacts with it. Create the Client File First, create a new file: touch client.py Then, implement the client: import asyncio from mcp import ClientSession, StdioServerParameters from langchain_openai import ChatOpenAI from mcp.client.stdio import stdio_client # Define server parameters server_params = StdioServerParameters( command="python", args=["math_server.py"], ) # Define the model model = ChatOpenAI(model="gpt-4o") async def run_agent(): async with stdio_client(server_params) as (read, write): async with ClientSession(read, write) as session: await session.initialize() tools = await load_mcp_tools(session) agent = create_react_agent(model, tools) agent_response = await agent.ainvoke({"messages": "what's (4 + 6) x 14?"}) return agent_response["messages"][3].content if __name__ == "__main__": result = asyncio.run(run_agent()) print(result) Your client is now set up and ready to interact with the MCP server. Running the MCP Server and Client Step 1: Start the MCP Server Open a terminal and run: python math_server.py This starts the MCP server, making it available for client connections. Step 2: Run the MCP Client In another terminal, run: python client.py Expected Output 140 This means the AI agent correctly computed (4 + 6) x 14 using both the MCP server and GPT-4o. Conclusion Integrating MCP with Azure OpenAI Services enables AI applications to securely interact with external tools, enhancing functionality beyond text-based responses. With standardized communication and improved AI capabilities, developers can build smarter and more interactive AI-powered solutions. By following this guide, you can set up an MCP server and client, unlocking the full potential of AI with structured external interactions. Next Steps: Explore more MCP tools and integrations. Extend your MCP setup to work with additional APIs. Deploy your solution in a cloud environment for broader accessibility. For further details, visit the GitHub repository for MCP integration examples and best practices. MCP GitHub Repository MCP Documentation Semantic Workbench AI Gateway MCP Video Walkthrough MCP Blog MCP Github End to End Demo
