Model Migration Process on Microsoft Foundry and Azure OpenAI
Every app built on an LLM will eventually move to a new model. The model you shipped may be retired, or a newer model may offer better quality, cost, or performance. Changing a model name in code from a retiring model such as gpt-4o to a newer one such as gpt-5.1 may take one line. That line hides a much larger migration. Model failures are often silent to the systems using the model and loud to users. Nothing crashes. Error rates stay flat. Every dashboard says the migration went fine. Meanwhile, responses change shape, summaries become longer and more hedged, JSON fields disappear, and tool calls fire in a different order. Users notice. Support queues grow. Downstream code that depended on the old behavior starts to break. A successful migration preserves the application's behavior or improves it in measurable ways. That requires a repeatable process to detect drift, adapt safely, and prove quality before broad rollout. The model migration process has six phases: Discover → Assess → Adapt → Validate → Roll out → Retire. This article explains what each phase looks like, which Microsoft Foundry tools support it today—including Azure OpenAI capabilities—and where teams still need to build around the platform. It then applies the process to a retail shopping assistant and points to additional resources in Go deeper at the end of this post! Why migrate now Every model has a retirement date. On Microsoft Foundry, generally available models typically ship with a retirement date about 18 months out, and older model families are actively replaced. For example, the model lifecycle and retirement schedule lists gpt-4o (2024-05-13) as retiring on October 1, 2026, with gpt-5.1 as its replacement. What happens at retirement depends on how you buy capacity: Standard, Global Standard, and Data Zone Standard (pay-as-you-go) deployments are auto-upgraded on a rolling, region-by-region schedule. You control the timing with versionUpgradeOption set to one of: OnceNewDefaultVersionAvailable, OnceCurrentVersionExpired, or NoAutoUpgrade. NoAutoUpgrade means the deployment stops working at retirement. Priority Processing follows the same path. Provisioned (PTU) deployments are not auto-upgraded. You migrate them yourself, either in-place (traffic moves over a 20–30 minute window with no downtime) or side-by-side (stand up the new deployment, test, shift traffic, delete the old one). Batch deployments follow the side-by-side path: deploy the new model, resubmit jobs, retire the old deployment. The developer problem is the same in every case: traffic eventually reaches a different model, but the platform cannot tell you whether the application still behaves as it did before. A responding endpoint does not prove that the app behaves correctly. A new model can change formatting, tone, tool-calling behavior, or JSON shape in ways that quietly break downstream code. When should I migrate? Start before the retirement date. Automatic upgrade handles the traffic transition for eligible deployments, but the team still owns behavioral validation. Provisioned deployments also require a manual migration. Microsoft typically makes a replacement available in Global Standard about 90 days before retirement, in provisioned regions about 30 days before retirement, and in standard regions about two weeks before retirement. That gives you time to evaluate the new model on your own terms. Retirement dates cannot be extended. You also do not need a deprecation notice to begin. If a newer model may improve quality, speed, or cost, run it through the process now. Waiting turns the switchover into a slow train wreck: responses drift, parsing becomes brittle, support tickets accumulate, and the team ends up debugging a model it did not choose on a date it did not pick. A deliberate migration makes the retirement date a formality and creates a process the team can reuse. Who this is for This process fits teams that own an LLM-powered feature inside a larger application and run migrations deliberately. It also applies to AI-native platform teams that centrally manage models for other application teams. The phases remain the same, though platform teams may run them faster and in parallel rather than in sequence. Fine-tuned workloads are out of scope here because they cannot be upgraded automatically, have separate training and deployment retirement schedules, and turn the Adapt phase into a distillation or retraining exercise rather than primarily prompt work. The six phases Phase Definition What success looks like Discover Learn that a model change is coming or needed. The team receives a timely, structured signal with the deprecation date, replacement model, and migration window. Assess Choose a target model and confirm that it is operationally available. The team understands the candidates and confirms capacity, region, and SKU before tuning starts. Adapt Replay the current workload on the new model, diagnose changes, and update prompts, parameters, tool definitions, output schemas, and calling code. The team runs side-by-side replay against real or representative traffic, can see the behavioral differences, and records every change. Validate Run the adapted workload against a quality rubric and decide whether it is safe to ship. The team has an evaluation suite that is affordable to run and trusted by application owners and reviewers. Roll out Promote the model through staged production exposure, monitor live behavior, and commit or roll back. Canary or weighted routing is in place, live quality is measured alongside latency and errors, and rollback remains possible. Retire Decommission the old deployment, free capacity, archive evaluation artifacts, and update internal documentation. The old SKU is gone, the deployment count falls, and the team carries what it learned into the next migration. Foundry tools at a glance Microsoft Foundry provide tools for each phase of the Model Migration Process. Phase Microsoft Foundry feature (including Azure OpenAI) Documentation Discover Model retirement schedule, lifecycle policy, Service Health alerts, and Models API lifecycleStatus Model retirement schedule Lifecycle policy Assess Model leaderboards and benchmarks for quality, safety, cost, throughput, and latency; trade-off charts; side-by-side comparison; suggested replacements Model leaderboards and benchmarks Side-by-side compare Adapt Prompt Optimizer in the Foundry Agent playground; agent optimization; simulator for synthetic data Prompt Optimizer Agent optimization Simulator Validate Azure AI Evaluation SDK with 30+ evaluators, LLM-as-judge, graders, and the portal evaluation wizard Azure AI Evaluation SDK Portal evaluation Roll out Automatic upgrade and versionUpgradeOption; provisioned in-place or side-by-side migration; continuous evaluation; Azure Monitor alerts Auto-upgrade with versionUpgradeOption Continuous evaluation Retire Models API to confirm 410 Gone; observability dashboard to track deployment count Models API Observability dashboard Breakdown of each phase 0. Prepare the test dataset Before starting the six phases, build a set of representative inputs, expected outputs, and agreed success criteria. This dataset gates the middle of the lifecycle: Adapt needs inputs for replay, and Validate needs ground truth and scoring criteria. Step 0 describes the workload rather than the candidate model, so it can begin during Discover, before the team selects a target. Build the dataset from captured production traffic or domain examples in .csv or .jsonl. If representative data is not available, use the simulator to generate synthetic inputs. Two practices determine whether this work pays off: Instrument capture before you need it. Production content capture is opt-in and never retroactive. Log prompts, responses, latency, and token counts now so the team has traffic to evaluate later. Freeze the dataset. Keep inputs, ground truths, and success criteria fixed throughout the migration. If they change, source and target results are no longer comparable. You also need an inventory of the model deployments your workload uses, including their deployment types (Standard, Provisioned, or Batch). For each source model, note its retirement date and suggested replacement from the Model retirement schedule. 1. Discover Discover begins when something forces the team to consider a model change: a deprecation notice, a new generally available model, a cost or latency problem, or a capability gap. The phase ends with a decision to begin migration or stay on the current model if it remains stable, performs well, and is not approaching retirement. Foundry tools. The model lifecycle and retirement schedule publishes retirement dates and suggested replacements. The Azure OpenAI model retirements documentation explains notification timing, including at least 60 days for generally available model retirements and at least 30 days for preview model retirements. It also explains how to configure Azure Service Health advisories and use the Models API for programmatic lifecycleStatus and deprecation checks. Those APIs provide the foundation for an internal discovery system. Where it breaks. Customers may learn about a retirement through email, a service health alert, or a production error. By the time the right team sees the signal, it may already be deep into the deprecation window and heading toward retirement. What your team provides. The schedule and Models API expose the data through a stable contract. Mature enterprises may add a thin notification layer that routes it to the right owners. 2. Assess The team chooses a candidate target model and confirms that it is usable: the correct region and SKU, enough quota, and availability alongside the current model so rollback remains possible. Assess also includes projecting monthly cost against historical traffic. Pricing structures change between model generations through reasoning tokens, cached input, structured-output overhead, and other factors. Those changes can move unit economics by 2x or more. For regulated workloads, compliance requirements such as BAA, FedRAMP, and regional Standard versus Global Standard availability may narrow the candidate list before quality testing begins. Foundry tools. Start with the replacement suggested in the retirement schedule, then build a shortlist with model benchmarks, which compare quality, safety, cost, throughput, and latency. Use trade-off charts such as quality versus cost and the side-by-side model comparison for up to three models. Compare context windows, feature support such as function calling, structured output, and vision, and available endpoints. Confirm SKU, region, quota, and upgrade mechanics in the model retirements documentation. Where it breaks. Teams face several plausible candidates, such as gpt-5.1, gpt-5.2, and a nano variant, without clear positioning between them. A selected model may be unavailable in the required region or SKU, a constraint that sometimes appears only after planning is underway. Historical traffic may also show that the new model costs substantially more, forcing an unplanned budget decision. What your team provides. Public benchmarks should filter the candidate list, not make the final decision. Confirm the shortlist against the team's own workload. Build the monthly cost view from token logs and current pricing. 3. Adapt Adapt is often the most time-consuming phase for embedded and product-facing workloads. Validate may take longer for regulated workloads. First, replay the existing workload on the new model without changing it. This isolates changes caused by the model. Diagnose shifts in verbosity, reasoning depth, structured-output adherence, tool-call shape, and latency. Then update the application until it recovers or improves on the previous behavior. Prompt editing is only one part of Adapt. A migration often changes four other surfaces: Parameters. temperature, top_p, max_tokens, and reasoning-effort controls may not map directly between generations. Some are unsupported by newer model families. Tool definitions. Argument names, descriptions, and required fields that reliably guided the old model may need clearer wording or tighter constraints. Output schemas. Structured-output behavior changes between models. A schema the old model followed loosely may need explicit constraints, or the new model may finally enforce it. Calling code. API and SDK differences, including Chat Completions versus Responses, streaming formats, and new or renamed request fields, can require code changes. Downstream parsers may also assume the old response shape. For agentic and workflow workloads, schema and tool-call changes can outweigh prompt changes. Foundry tools. Prompt Optimizer is available through the Optimize button below the system instructions field in the Agent playground. It restructures instructions, explains each change by paragraph, and supports iteration. For example, a team can add a constraint such as "keep the JSON schema exactly" and optimize again. It is a fast first pass for a prompt that would otherwise be rewritten by hand. For agent workloads, agent optimization tunes instructions, tools, and model selection together. Prompt Optimizer and agent optimization are available in Microsoft Foundry, not Azure OpenAI. When production data is unavailable, the simulator can generate synthetic and adversarial inputs. Where it breaks. Most migration time is spent in a manual diagnosis loop. Teams rerun prompts by hand, compare outputs by eye, and rarely record what changed or why. For agent builders, chat benchmarks may miss tool-call regressions such as extra fields, renamed arguments, or changed call sequences. Those problems appear only when the team replays real agent traces. Plan for three constraints: Start with the optimizers, then verify their output. They apply general practices in a single pass rather than fitting changes to the team's dataset. They tune instruction text, not tool definitions or output schemas. Copy the original prompt first because there is no version history, then evaluate the optimized prompt against the frozen dataset. Expect more manual work when moving between providers or model families. There is no "optimize for target model X" flow. Moving from one family to another, such as OpenAI to Claude, still requires deliberate prompt and schema translation. Record traffic before you need it. Replay is only as useful as the captured data. Existing traces are available as an evaluation source for agents today, while content capture is opt-in and never retroactive. Log prompts, responses, latency, and tokens now to prepare for the next Adapt phase. 4. Validate Run the adapted workload against a quality rubric on the frozen dataset. The rubric may combine rules, LLM-as-judge evaluation, human review, existing user-feedback signals, or a domain-specific scoring framework. Examples include a clinical summarization rubric for healthcare or a tool-call sequencing assertion for agents. Validation produces a pass-or-fail decision for production exposure. AI-native teams may run the same signal continuously on every commit rather than treating it as a one-time gate. The dataset is a dependency for both Adapt and Validate. Build and freeze it early, around Assess, even though its primary purpose belongs to this phase. Validation then has two touchpoints: Before Adapt, freeze the dataset and success criteria, then run the current model to establish the source baseline. After Adapt, run the target model against the same dataset and evaluators, compare it with the source baseline, and make the release decision. Prepare the evaluation runner early and apply the gate after Adapt. Both steps belong to Validate. Foundry tools. The Azure AI Evaluation SDK, installed with pip install azure-ai-evaluation, includes more than 30 evaluators. They cover grounding, relevance, retrieval, coherence, fluency, question answering, reference-based similarity, F1, BLEU, ROUGE, safety, agent behavior, and Azure OpenAI graders. Teams can also build custom LLM-as-judge evaluators for task-specific rubrics. The portal evaluation flow runs the same evaluators against model, agent, dataset, and trace targets. Run identical evaluators against source and target outputs on the frozen dataset so the results remain comparable. Measure the three dimensions used for sign-off: Quality: evaluator results Latency: leaderboard time to first token and throughput, plus operational latency from the workload Cost: (input tokens × input price) + (output tokens × output price) Where it breaks. Most teams do not have an evaluation suite. Teams that do often built it themselves and may not use platform evaluation tools. Regulated workloads add mandatory human review, which can become the bottleneck. For those teams, migrations often stall in Validate rather than Adapt. What your team provides. The evaluators are ready to run, but model workloads still require teams to curate a domain-relevant test set from production traffic. That is why Phase 0 pays for itself. 5. Roll out Promote the validated configuration in stages: non-production, then a canary or weighted percentage of production traffic, followed by broader exposure. Compare live latency, errors, and quality signals with the pre-migration baseline, then commit or roll back. Some workloads cannot expose a new model to customer traffic during testing, including flows involving protected health information or financial transactions. Use shadow or mirror mode instead: run the new model offline against production inputs and compare its outputs with the old model without affecting users. Foundry tools. Migration mechanics depend on the deployment SKU: Standard, Global Standard, and Data Zone Standard deployments upgrade automatically on a rolling schedule. Control timing with versionUpgradeOption: OnceNewDefaultVersionAvailable, OnceCurrentVersionExpired, or NoAutoUpgrade. Priority Processing follows the same path. Provisioned, Global Provisioned, and Data Zone Provisioned deployments migrate manually, either in place during a 20-to-30-minute Azure-managed traffic transition or through side-by-side deployments. Batch deployments migrate side by side. Deploy the new model, resubmit jobs, then retire the old deployment. Fine-tuned deployments do not upgrade automatically. They follow separate training and deployment retirement schedules, so plan retraining or distillation early. See the model retirements documentation for deployment-specific guidance. Use continuous evaluation to score a sample of production traffic in the Foundry Observability dashboard. Connect evaluation results to traces for root-cause analysis and configure Azure Monitor alerts for quality regressions. Where it breaks. Offline evaluation can miss production quality and latency regressions. Rollback decisions may also be forced by deprecation deadlines rather than evidence. What your team provides. Teams implement weighted routing between deployments in their application or gateway layer. They must also choose how long to keep the old deployment warm for rollback. Embedded copilot teams often target about 30 days. Design both mechanisms once and reuse them for future migrations. 6. Retire Retire is easy to forget. Decommission the old deployment, free its capacity, archive evaluation artifacts, update internal documentation, and communicate the change to downstream owners. That may include customer-facing documentation, marketing pages, support runbooks, and audit logs. Regulated workloads may need to retain artifacts for years. Retirement is also a governance step. Foundry tools. Use the Models API to confirm that the old version is retired through lifecycleStatus or 410 Gone. Use the observability dashboard to confirm that the active deployment count falls. Add useful production traces to the golden dataset so the next migration starts with better evidence. Where it breaks. Teams skip the phase. Zombie deployments accumulate, leaving teams with structural debris from migrations they never finished. What your team provides. The observability dashboard shows deployment count, but the team must decide which deployments still carry traffic. Create an explicit retirement ticket rather than relying on someone to remember. Embedded copilot teams also need to update public claims such as "powered by gpt-4o" after the model changes. Worked example: Zava's Shopping Assistant migrates from gpt-4o mini to gpt-5.x Zava is a fictional retailer used as a stand-in for a real customer story. The example reflects patterns observed in customer-facing embedded AI workloads. Zava's Shopping Assistant is one of the company's largest LLM workloads. It has two LLM stages: Per-review insight extraction identifies sentiment, attribute mentions, and defect signals across thousands of product reviews. Product-level summaries present those findings to shoppers on the product page. Together, the two stages account for a meaningful share of Zava's token volume. Discover Zava's central AI Platform team made gpt-5.x models available internally and notified feature teams. The Shopping Assistant team learned about the models through that channel and received a target migration window before gpt-4o mini's deprecation. Zava has an internal discovery layer built on the retirement schedule and Models API. Microsoft provides the underlying data, while Zava routes the signal to application owners. Assess The team compared gpt-5.4 nano, which offered lower latency and cost, with gpt-5.1 and gpt-5.2 using leaderboard trade-off charts. Selection remained difficult because of the rapid release cadence, unclear positioning between variants, and the lack of a behavioral benchmark for product question-and-answer workloads. Capacity planning required coordination with the AI Platform team. Both gpt-4o mini and the gpt-5.x candidate needed to remain available in the same regions so the team could roll back. Adapt The team ran its existing Shopping Assistant prompts against gpt-5.4 nano using a sanitized traffic sample. Customer queries were scrubbed of personally identifiable information before replay. The behavioral comparison found three problems: Summaries used more hedged language and sometimes contradicted the underlying review evidence, creating a shopper-trust risk. Insight counts varied across runs. The model sometimes extracted substantially more or fewer attribute mentions than gpt-4o mini, affecting downstream filtering. Latency varied more than expected on the synchronous product-page path. Prompt Optimizer helped restructure the summary prompt, but the team still diagnosed the differences manually. It built its own replay system and behavioral comparison on top of captured traffic. Reengineering took weeks and extended beyond prompts: parameters and downstream parsing for the insight-extraction output also changed. Validate The team scored outputs with Zava's Product Answer Quality (PAQ) rubric. Its nine criteria cover factual grounding, attribute accuracy, tone, and refusal behavior for questions outside the catalog. Zava implemented the rubric as custom evaluators in the Azure AI Evaluation SDK. Initial evaluations used unchanged prompts to isolate model behavior. The team reran them after each prompt change. Zava's QA team also completed a manual review, which the company requires for every new model used in a customer-facing workflow. The per-review insight extraction stage still has no automated evaluation, a gap the team has accepted for now. Roll out The validated configuration moved to non-production and then through staged exposure: employees first, followed by a small percentage of shoppers. The canary exposed latency regressions that offline evaluation had missed. The team rolled back the latency-sensitive synchronous product-page path while keeping the offline pregeneration path on the new model. Retire Retirement is not complete. The gpt-4o mini deployment remains warm for rollback. The team must resolve the synchronous-path latency regression before retiring it, which sends that code path back to Adapt. This split state is common. Retire can lag Roll out by weeks or months, and the old deployment remains visible in deployment-sprawl data. Lessons from the example Adapt consumed most of the schedule. Replay tooling, behavioral comparison, and prompt reengineering are the clearest opportunities for Microsoft to shorten migrations. Validate worked because Zava had invested in it. Most customers do not have an equivalent to PAQ. Making domain-specific evaluations cheaper to build would improve confidence in this phase. The migration is partially live and partially rolled back. The process must support split-state workloads rather than assuming a binary switch from old model to new. How to use this process The six phases can serve as a checklist and an interview script for teams creating or auditing a migration process. Documentation and process: Lead with the six phases. Most teams recognize them immediately. Investment priorities: Start with Adapt and Validate. Across customer stories, those phases consume the most time and confidence. Interviews and postmortems: For each phase, ask whether it happens, who owns it, which tool the team uses, where it failed last time, and what evidence would increase confidence. Metrics: Discover and Retire are the easiest phases to instrument through measures such as announcement reach and active deployment count. Adapt and Validate require purpose-built telemetry that most teams do not yet have. Go deeper Two companion resources turn the process into concrete implementation steps: Microsoft Learn guide: This article follows the six phases through identifying affected deployments, preparing a test dataset, adapting prompts, evaluating source and target models, and rolling out by deployment type. Foundry Models Accelerator: This community toolkit includes a deployment-inventory scanner, a feasibility and assessment playbook, code and API migration audit scripts, an A/B evaluation runner with golden datasets, and rollout guidance. It follows the same six-phase process. The Foundry Models Accelerator is a community-built toolkit provided as-is under the MIT License. It falls outside Microsoft Support. Always verify model availability and retirement dates against official documentation. Additionally, check out the Foundry Forgebook which hosts a plethora of recipes that walk through the required code changes to migrate from different source to target models, even across model families. The goal of a model migration is to change the model without changing your application’s behavior, or to change it measurably for the better. Lead with the six phases, invest first in Adapt and Validate phases, and treat the Retire phase as a governance step.Adding a Fallback Model to Hermes with Microsoft Foundry
So the plan was simple. Leave the Bedrock configuration untouched, then wire Microsoft Foundry in behind it as a fallback, so Hermes always has somewhere else to go when the primary provider is not responding. A few other reasons pushed me towards Foundry in particular: Redundancy that does not need me. If Bedrock is throttled or out of quota, I want Hermes to fail over on its own rather than waiting for me to notice. A catalogue I already pay for. Foundry puts the latest GPT models next to open-weight and partner models in one place, so I can pick a model that suits the task instead of settling for whatever a single provider happens to offer. Enterprise controls out of the box. Region pinning, private networking, content filters and per-deployment quota all sit in the same portal, which makes the setup far easier to defend to a security reviewer. Learning the mechanics before I need them. Working out how Hermes handles a provider chain is much nicer on a quiet Tuesday than during a live outage. Here is the short version, if you are deciding whether to read on. Time: about thirty minutes if nothing goes wrong. Cost: pay-as-you-go tokens only, and none at all while the fallback sits idle. Result: an assistant that keeps answering when your primary provider stops. Before you start, you will need three things: a machine with Hermes already installed and a working primary provider configured, an Azure subscription with access to Microsoft Foundry in a region you can actually deploy into, and enough quota in that region to create a deployment. One thing that made this easy to justify: Foundry deployments bill per token on the standard pay-as-you-go tier. A fallback provider that never gets invoked costs nothing beyond the requests it actually serves, so the insurance is close to free until the day you need it. Chat surface (CLI, messaging) → Hermes Gateway → Primary Amazon Bedrock → Fallback Microsoft Foundry Figure 1: Where the fallback sits. Every request goes through the Hermes gateway to the primary provider; only when that provider is unavailable does the chain continue to Microsoft Foundry. Part 1: Deploying a Model on Microsoft Foundry The first half of this job happens entirely inside the Microsoft Foundry portal and has nothing to do with Hermes yet. All you are really doing here is making sure your Azure subscription can serve a model, and that you hold an endpoint and key Hermes can authenticate with later. 1. Deploy model in Foundry → 2. Copy endpoint + key → 3. hermes fallback add → 4. Authenticate → 5. Select models, test Figure 2: The whole setup in five moves. The first two happen in the Microsoft Foundry portal (orange); the rest happen on the Hermes machine (blue). Go to Microsoft Foundry > Build > Models > Deploy > Deploy a base model. You can deploy a fine-tuned model instead if you already have one, which works just as well with Hermes. Check the region shown at the top of the portal before you commit, because both model availability and deployment quota differ from one region to the next. Then deploy the model you have selected: In this case I deployed gpt-5.6-sol, which is the model Hermes will fall back to. The choice was deliberate rather than exciting. My primary model on Bedrock is a general-purpose chat model, and a fallback is only useful if the answers it gives feel like a continuation of the same conversation rather than a different assistant wearing the same name. The gpt-5.6-sol deployment matches that behaviour closely, it was available in the region I wanted to pin, and the quota I was granted comfortably covers a day of normal use. If a fallback surprises you the first time it fires, it is the wrong fallback. Once the deployment finishes, open it and take note of two values: the target endpoint URI and the API key. Copy both somewhere safe now, because you will be pasting them into Hermes in the next part. If your organisation rotates keys on a schedule, use a key with the longest life you are allowed, since a fallback secured with a credential that expires quietly stops being a fallback. What to copy Where it lives in the portal Where Hermes asks for it Target endpoint URI Deployment > Endpoint > Target URI "Endpoint" prompt in hermes fallback add API key Deployment > Endpoint > Key "API key" prompt, or choose Entra ID instead Deployment name Deployment > Details > Name Shown in the model list Hermes returns Region Top of the portal, next to the resource Must match the region you deployed into Figure 3: Everything Hermes will ask for, and where to find each value before you leave the portal. Part 2: Adding Foundry to Hermes as a Fallback With the Foundry side sorted, everything from here happens in the Hermes CLI. One thing worth knowing before you start: this is the fallback command, not the primary model command, so your existing Bedrock configuration is left completely alone. Nothing in this section can break what is already working, which makes it a good one to try on a live setup. Run the Hermes fallback command: When Hermes asks which provider to add, choose Azure Foundry. The picker still carries the old name; it is the same service that the portal now calls Microsoft Foundry. Paste the target endpoint URI from your deployment, then authenticate with the API key you copied earlier. Hermes also offers Microsoft Entra ID at this prompt, which is the better option if your organisation would rather not have a static key sitting on the machine. If authentication fails here, check the endpoint before you start suspecting the key. In my experience the endpoint is wrong far more often than the credential is, usually because the deployment name at the end of the URI does not match the deployment you actually created. Once authentication succeeds, Hermes lists the deployments your Foundry resource exposes and asks which ones you want to use. You can select more than one, and the order is not cosmetic: Hermes walks down the chain from top to bottom whenever the provider above is unavailable. Treat that list as a priority order, not a shopping basket. What happens to the primary What Hermes does What you see in the chat Responds normally Routes every request to the primary and never touches the chain Nothing. The fallback stays idle Throttled or out of quota Retries the next provider down the chain on the same request A reply, served by the fallback model Endpoint unreachable Keeps failing over on each new request until the primary recovers Slightly different tone and latency, but a working assistant Every provider fails Returns the error rather than hanging An error worth chasing with hermes status Figure 4: The chain in practice. The fallback only earns its keep in the middle two rows, which is exactly why it is easy to forget you configured it. Part 3: Promoting Foundry to the Primary Model At this stage Foundry is sitting in the back seat as a backup. I wanted to reverse the arrangement and make Foundry the primary while Bedrock slides down into the fallback slot, partly because I preferred keeping day-to-day traffic inside my Azure subscription, and partly because I wanted proof the chain works in both directions. Before promotion After promotion Primary: Amazon Bedrock → Primary: Microsoft Foundry Fallback: Microsoft Foundry → Fallback: Amazon Bedrock Figure 5: The promotion, in effect. Nothing is added or removed; the two providers simply trade places in the chain. There is no dedicated "promote" command in Hermes, so the manual route is a short sequence of steps rather than a single instruction: Select the fallback provider/model as the new primary: hermes model Remove the now-duplicate model from the fallback chain: hermes fallback remove Optionally add the old primary model as a fallback: hermes fallback add Restart the messaging gateway: hermes gateway restart Verify the result: hermes status / hermes fallback list That sequence works, and it is good to know what is happening underneath. But since I already had a working provider configured, I would rather just ask Hermes to rearrange itself. This is the part I genuinely enjoy about the tool: the configuration is something you can talk to, not only something you type commands at. Prompt: Okay now please make the model I configured on Microsoft Foundry into the main model, and make the Bedrock one the fallback model! Hermes rewrites the provider chain on its own and confirms the swap once it is done, which is a great deal less error-prone than running the five commands by hand. Part 4: Testing the Switch Configuration you have not tested is just an assumption with extra steps, so the next thing is to confirm Hermes really is talking to Foundry. Type /model when running Hermes to bring up the model picker. You will be prompted to select a provider first. Pick the Microsoft Foundry entry, then choose the specific deployment from the list underneath it. The active model should switch straight away. Send it a plain "Hello" to check that the deployment actually responds, rather than just looking correct in the menu. Appearing in a dropdown and serving a request are two very different things. A second test is worth the thirty seconds it costs: run hermes status to confirm which provider is live, then hermes fallback list to confirm the chain is ordered the way you intended. The picker tells you what you selected; those two commands tell you what Hermes will actually do at three in the morning. Part 5: The Obstacle, and What It Actually Taught Me Every walkthrough has the part the author quietly leaves out. Here is mine: the wrinkle was not the model, it was capacity. My first attempt deployed into the region closest to me out of habit, and the portal turned it down because there was no capacity left for that model at the tier I asked for. The model was clearly listed in the catalogue; being listed and being deployable in your region, on your subscription, at your quota, are three separate questions. Redeploying in a different region fixed it in a couple of minutes, but it meant the endpoint URI changed, which in turn meant the value I had already pasted into Hermes was stale. Re-running hermes fallback add against the new endpoint sorted it out. The lesson is cheap enough to hand over for free: check quota and regional capacity for your specific subscription before you design a walkthrough, a demo or a production fallback around one deployment. In the Foundry portal, Management then Quota shows exactly what you have been granted per region and per model family, which is the only list that matters. Symptom Likely cause Fix Deployment rejected in the portal No capacity for that model at the tier you asked for, in that region Deploy in another region, or drop to a smaller tier Hermes rejects the credential Endpoint URI does not match the deployment you created Re-copy the target URI from the deployment, not the resource Provider authenticates but lists nothing Key belongs to a different Foundry resource Check you are in the right resource, then re-run hermes fallback add Fallback never fires Chain ordered the wrong way round hermes fallback list, then reorder Figure 6: The four things that went wrong, or nearly did, and what fixed each one. There is a silver lining worth stating plainly. Because the fallback chain was already in place, a deployment that refused to come up did not take the assistant down with it. That is precisely the scenario this whole exercise was meant to cover, and it turned up on day one without me having to simulate it. Command Cheat Sheet Everything used in this walkthrough, collected in one place: hermes fallback add: attach a provider to the fallback chain hermes fallback remove: drop a provider from the chain hermes fallback list: show the chain in priority order hermes model: set the primary model hermes gateway restart: restart the messaging gateway after a change hermes status: confirm which provider is currently live /model: switch models from inside a running session Conclusion Adding Microsoft Foundry as a fallback behind my existing Bedrock setup took an afternoon, and most of that was spent recovering from a regional capacity limit I should have checked first. The work itself is small: deploy a model, copy the endpoint and key, run hermes fallback add, authenticate, pick your deployments. The payoff is that Hermes no longer depends on one provider staying healthy. Three things are worth carrying away from this: Check quota, not just the catalogue. The Foundry catalogue shows what Microsoft offers. It does not show what your subscription and region can actually deploy today. Confirm that first, before you build anything on top of a specific deployment. Order your fallback chain deliberately. Hermes works down the list from top to bottom, so the sequence you choose during setup is the failover policy you are going to live with. Put the model you actually trust at the top. Treat the endpoint as part of the credential. Redeploying in a new region changes the endpoint URI, and a fallback pointed at an endpoint that no longer exists is not a fallback. Re-run the setup whenever the deployment moves. The switch from Bedrock primary to Foundry primary also proved the chain runs in both directions, which is the real point. Provider redundancy is only useful if you have watched it work. Next on my list is deliberately breaking the primary provider to confirm the failover triggers on its own, without me typing a single command. If you run this against a different model, region or provider pairing, I would genuinely like to know how it went, particularly if your quota experience was better than mine. Drop it in the comments.
Making Azure AI Foundry Agents Explainable — Knowledge Graphs + Source Attribution
90% of Azure AI demos work on stage — most never ship. The gap is architecture, not the model. I wrote up a field guide on taking Azure AI Foundry agents from POC to production, with knowledge graphs (GraphRAG) doing the grounding and source attribution. What the post covers Grounding with a knowledge graph — multi-hop retrieval + inline citations so every answer is traceable to a source (critical for regulated/medical use cases). Externalized state — keeping agent memory and session state outside the model. Identity at the boundary — Entra ID / RBAC instead of trusting the prompt. Observability & compliance — tracing, evaluation, and auditability. The stack — Azure AI Foundry + Model Context Protocol (MCP) + Azure Functions (Flex Consumption) + Azure OpenAI, from a real build (VeritasGraph medical MCP server). 📖 Full write-up: https://bibinprathap.com/blog/azure-ai-proof-of-concept-to-production ▶️ 6-min walkthrough: https://youtu.be/z-CPS5WUvyw?si=fmpo1RN28Bh9KbIb Questions for the community How are you grounding Foundry agents today — vector RAG, GraphRAG, or hybrid? Anyone combining knowledge graphs with MCP tools in Foundry? What worked / broke? For regulated domains, how are you handling source attribution and audit trails? Curious to compare notes — happy to share more detail on the GraphRAG retrieval design if useful.Model router updates: new regions, a refreshed model pool, and understanding the hill climb
Across Microsoft, "hill climbing" has become shorthand for how real AI progress happens: not in one dramatic leap, but through a disciplined loop. Microsoft AI defines the hill climb as an organization that continuously improves, cycle after cycle, through more compute, better data, and sharper evaluation. Reinforcement fine-tuning in Foundry defines it as improving the deployable model package one measured step at a time across quality, latency, and cost. Different altitudes, same premise: progress is not a one-shot decision. It's a loop. For most teams, the decision of what model to use when is made manually or with custom routing tools. A developer picks a model based on benchmarks, familiarity, or the last launch that made headlines, ships it, and revisits the choice only when something breaks. In an ecosystem where the frontier moves monthly, that decision goes stale fast. Model router in Foundry Models brings the hill climb to the selection layer. What's new: a bigger pool, in more places This release expands where teams can deploy model router, broaden the supported model pool, and delivers updates through a stable endpoint. Together, these changes help teams run production workloads in more locations, match a wider range of tasks to suitable models, and adopt supported updates without changing the application integration. A refreshed model pool. The supported model list now includes Anthropic Claude Opus 4.8 — a high-capability model built for complex reasoning and long-form generation, for scenarios that demand depth, structure, and quality — and the GPT-5.6 family. Just as importantly, the pool is pruned: gpt-5-chat, gpt-5.2-chat, gpt-5.3-chat, Deepseek-V3.1 have been removed from the model router as models reach the end of their lifecycle and are deprecated in Foundry. New region availability. The model router is now available in 28 regions for global standard and 21 data zone regions. For many organizations, inference requests must stay within specific geographic boundaries for regulatory, governance, or customer-trust reasons — and intelligent routing shouldn't force a compromise on that. Find the full list of regions here. The most important detail is what you don't have to do: these updates occur automatically*. The endpoint remains stable as the supported model pool is refreshed, so teams do not need to redeploy the model router to receive the update. Applications can continue using the same integration while the model router evaluates requests against the current supported pool. Teams should continue monitoring routing traces and application outcomes to confirm that quality, cost, latency, and governance requirements are met. *Models from Anthropic still need to be deployed separately before they can be routed to through the model router. Interested in hearing more about what's new to the model router? Tune in for the next episode of Model Mondays with Sanjeev Jagtap and Lee Stott, where they talk all things model router from evaluations to hill climbing. Sign up here to watch live or view the replay: Model Mondays - Spotlight On Model router in Microsoft Foundry | Microsoft Reactor The selection-layer hill climb At the selection layer, a step is a routing decision. Each one is a micro-optimization against your objective, and each one is instrumented: every response from the model router includes a model field showing which underlying model was selected, so the climb leaves a complete, auditable trail. Model router supports three parts of the optimization loop: A/B testing to compare two router configurations to understand quality, cost, and latency tradeoffs; model decomposition to use routing results to decompose a single-model application into a multi-model or multi-agent design, and continuous routing to keep the router in production for continuous per-request selection. Each pattern turns model choice into a measured, repeatable process rather than a fixed decision. 1. A/B Testing Question: Which model or routing strategy should I use in production? A/B testing helps teams compare candidate models, model families, or router configurations against the same workload. Representative traffic is sent to competing deployments, and teams compare quality, cost, latency, and governance outcomes. The goal is to understand tradeoffs and identify the model or routing strategy that best meets workload requirements before promoting it to production. 2. Model Decomposition Question: What work is my application actually doing? Model decomposition uses model router as a diagnostic tool. By deploying the model router against a representative workload and examining routing telemetry, teams can see how requests naturally separate into different task classes. Simple retrieval, classification, and summarization requests may route to smaller models, while reasoning, planning, and agentic workflows may require more capable models. The goal is not to choose a winner, but to understand the structure of the workload and uncover opportunities for optimization, specialization, or architectural improvements. 3. Route continuously Question: Why choose a single model at all? Route continuously is the pattern model router was designed for but is not limited to. Rather than treating model selection as a one-time decision, teams leave the model router in production and allow the best-fit model to be selected for each request. As the supported model pool, regional availability, and platform capabilities evolve, teams can continue using the same endpoint while evaluating whether updates improve workload outcomes. Model selection becomes an ongoing optimization process rather than a project that must be repeated every time the model landscape changes. Together, these patterns illustrate a broader shift: the model router is more than a model. It is a tool for the optimization loop itself, helping teams evaluate tradeoffs, understand workload behavior, test hypotheses, and continuously refine model selection as requirements evolve. Whether used to compare candidate models, decompose applications into specialized tasks, or automate per-request routing in production, model router turns model selection into an observable, measurable, and repeatable process. As the model landscape continues to change, that optimization loop becomes a durable advantage. Getting Started Ready to start your own hill climb? Whether you're exploring the model router for the first time, evaluating routing strategies against your workload, or building a long-term optimization practice, these resources can help you move from experimentation to production with Microsoft Foundry. What's new in model router? Sign up for the next Model Mondays episode for a deep dive into new features, optimization patterns, and the latest model router updates. How do I build agents with model router? Check out the Model Router Agents Lab and build agent experiences with routing, retrieval, web search, tool calling, and multi-agent patterns. How do I evaluate model router? Compare model router against baseline models using your own prompts, then review quality, cost, latency, and routing decisions with the Auto Evaluation Toolkit. How do I optimize model router for my workload? Start your hill-climbing journey with the Model Mastery workshop, where you'll test one optimization lever at a time and measure how each change impacts workload outcomes. How do I build a model router optimization playbook? Explore the Model Releases repository to track new capabilities, understand the optimization question behind each release, and try focused notebooks that demonstrate one optimization lever at a time.Introducing GPT-transcribe and GPT-live-transcribe in Microsoft Foundry
A transcription model hears “account number 8-4-7-2” but returns “account number eighty-four seventy-two.” A single error can break a downstream automation workflow. Developers building voice applications need transcription models that can handle real-world audio conditions, natural speech patterns, and business-critical details, including codes, dates, addresses, account numbers, mixed-language conversations, specialized terminology, and quiet or low-volume speech. GPT-transcribe and GPT-live-transcribe do just that and are available in Microsoft Foundry today. Two updates to the audio model family designed to improve automatic speech recognition across asynchronous transcription and live streaming scenarios. Built for More Accurate Transcription in Real-World Audio GPT-transcribe is the highest accuracy ASR model from Open AI, designed for asynchronous speech-to-text transcription of completed audio files and batch workloads. It accepts audio input and returns text output, making it a strong fit for workflows that process recorded, uploaded, or submitted audio, including meeting recordings, voicemails, and media files. GPT-live-transcribe is designed for low-latency streaming transcription through the Realtime API. It supports real-time audio input and text output, helping developers build live experiences where speech needs to be transcribed continuously as audio arrives. This model also introduces “tunable latency” where developers can adjust the latency/accuracy trade-off for streaming. It is a strong fit for live captions, voice assistants, contact center workflows, accessibility experiences, field service applications, real-time intake, and monitoring systems. Together, these models give developers transcription options in Microsoft Foundry for stored audio and live voice interactions. Their text output can support downstream workflows such as search, summarization, routing, analytics, automation, and quality review. What’s New in Both Models The features of the new transcription models focus on improving transcription quality in real-world audio environments where speech can be brief, noisy, accented, quiet, domain-specific, or mixed across languages. Key capabilities include: Background noise: Helps isolate speech in noisy environments so transcription quality can remain more reliable when audio conditions are not controlled. Short utterances: Improves recognition of brief commands, confirmations, interruptions, and clipped speech that can be difficult to capture accurately. Alphanumeric perception: Strengthens transcription of IDs, codes, phone numbers, dates, addresses, account numbers, and mixed letter-number sequences. Domain terminology understanding: Improves recognition of specialized vocabulary used in product, workflow, industry, and business-process contexts. Codemix: Improves understanding when speakers switch between languages within a conversation or utterance. Context awareness: Uses topic hints and past conversation context to improve transcription accuracy and help maintain consistency. Accent robustness: Improves handling of regional accents, non-native accents, dialects, and varied speaking styles. Whispering: Improves recognition of quiet or low-volume speech, including whispered commands and private dictation. Live captioning and accessibility experiences: Generate real-time captions for meetings, events, media experiences, and assistive applications. Contact center and voice workflows: Capture spoken details as conversations happen, supporting routing, quality review, summarization, and downstream automation. Monitoring, analytics, and compliance workflows: Provide text visibility into ongoing spoken input so teams can analyze, review, and act on conversation data. Also Available: GPT-realtime-2.1 and GPT-realtime-mini-2.1 gpt-realtime-2.1 and gpt-realtime-mini-2.1 are also available in Microsoft Foundry for developers building speech-to-speech applications. Unlike GPT-transcribe and GPT-live-transcribe, which return text, these models accept audio and generate audio for low-latency conversational experiences over the Realtime API. gpt-realtime-2.1 focuses on interaction quality and robustness, while gpt-realtime-mini-2.1 provides a smaller, faster, and more cost-efficient option for high-volume deployments. Together with GPT-transcribe and GPT-live-transcribe, these realtime audio updates give developers more flexibility to build voice applications that need both accurate transcription and responsive spoken interaction, whether the experience is centered on capturing speech as text, responding with audio, or combining both patterns in a single workflow. Use Cases by Model GPT-transcribe Use GPT-transcribe when the application needs accurate text transcripts from recorded, uploaded, or submitted audio. It is a strong fit for meeting and call transcription, media transcription, customer support intake, voicemail and message processing, quality review, compliance workflows, and domain-specific transcription where short utterances, structured alphanumeric details, specialized terminology, accents, background noise, code-mixed speech, or quiet audio can affect downstream accuracy. GPT-live-transcribe Use GPT-live-transcribe when the application needs live streaming transcription with low latency. It is designed for real-time captions, accessibility experiences, contact center transcription, voice-enabled workflows, live monitoring, operational dashboards, and agent-assist scenarios where spoken input needs to become text continuously as the interaction unfolds. Pricing The following pricing example shows Global Standard rates by model and modality. Rates for GPT-realtime-2.1 and GPT-realtime-mini-2.1 are listed per 1 million tokens. GPT-transcribe and GPT-live-transcribe are listed per audio hour. Model Deployment Modality Input Cached Input Output GPT-realtime-2.1 Global Standard Audio $32.00 $0.40 $64.00 Text $4.00 $0.40 $24.00 Image $5.00 $0.50 -- GPT-realtime-mini-2.1 Global Standard Audio $10.00 $0.30 $20.00 Text $0.60 $0.06 $2.40 Image $0.80 $0.08 -- GPT-live-transcribe Global Standard Audio -- -- $1.02/hour GPT-transcribe Global Standard Audio -- -- $0.27/hour Getting Started Choose GPT-transcribe when your application processes complete audio files asynchronously, or GPT-live-transcribe when it needs text continuously as speech arrives. Try the models in Microsoft Foundry, then use the resources below to explore the Realtime API, follow the audio quickstart, compare available models, and review Azure OpenAI in Foundry Models documentation. For asynchronous transcription, submit a complete audio file to GPT-transcribe and process the returned transcript after the request completes. This pattern works well for recordings, voicemails, and uploaded media. For streaming transcription, open a Realtime API session with GPT-live-transcribe, send audio as it is captured, and handle incremental transcript events. This pattern supports live captioning and agent-assist experiences that need text during an active interaction. Refer to the linked quickstart and Realtime API documentation for current SDK setup, authentication, request schemas, and supported audio formats. Explore Microsoft Learn documentation to learn more: Use GPT Realtime API for speech and audio with Azure OpenAI in Foundry Models GPT Realtime audio quickstart Azure OpenAI in Foundry Models overviewBringing Enterprise File Data to Users with Azure NetApp Files, Microsoft Foundry, and M365 Copilot
This is Part 3 of a 3-part series on extending AI to enterprise file data, showing how the knowledge pipeline is surfaced through enterprise AI agents and user experiences including Microsoft 365 Copilot.From Enterprise File Storage to an AI-Ready Data Foundation using Azure NetApp Files and OneLake
This 3-part series shows how to extend AI to enterprise file data – without migration – by combining Azure NetApp Files, OneLake, and a RAG-based architecture that surfaces grounded insights through enterprise AI agents. This is Part 1 of a 3-part series covering the data foundation, knowledge pipeline, and user experience layers.From File Data to AI‑Powered Knowledge Pipelines using Azure NetApp Files object REST API
This is Part 2 of a 3-part series on extending AI to enterprise file data hosted on Azure NetApp Files, building on the data foundation to create a knowledge pipeline that makes enterprise file data usable by AI systems.Signing in to Microsoft Foundry from OpenClaw using Azure AD: a smoother way to bring your models in
This post is a quick update to walk through the new flow. If you read the previous one, think of this as the easier path I wish I had the first time round. If you have not seen the original, you can find it here: Integrating Microsoft Foundry with OpenClaw: Step by Step Model Configuration | Microsoft Community Hub Pre-requisite: You will need the Azure CLI (azure-cli) installed on your machine. The official install guide for Linux is here: https://learn.microsoft.com/en-us/cli/azure/install-azure-cli-linux?view=azure-cli-latest I am on Linux so I went the Homebrew route, which keeps things simple. The formula is here: https://formulae.brew.sh/formula/azure-cli Microsoft also has official docs covering the Homebrew/Linuxbrew install: https://learn.microsoft.com/en-us/cli/azure/install-azure-cli-macos?view=azure-cli-latest#install-with-homebrew Once Homebrew is ready, run this in your terminal: brew install azure-cli Why this matters: Before this update, every Foundry model you wanted to use in OpenClaw needed its own API key and endpoint pasted into the config. It worked, but it was tedious, and keys are easy to leak if you are copying them around. The Azure AD path solves both problems. You authenticate as yourself (or a service principal), OpenClaw asks Azure for the list of Foundry resources you have access to, and it brings the models in automatically. Signing in to Microsoft Foundry from OpenClaw via Azure AD A device-code OAuth handshake replaces the old static-API-key flow. OpenClaw delegates auth to the local Azure CLI; the CLI handles the browser-side sign-in, holds the resulting tokens, and refreshes them silently. OpenClaw then walks the Azure resource graph, subscriptions → Foundry resources → model deployments and registers each model into its own config. No API keys move through OpenClaw at any point. Sequence diagram of the OAuth 2.0 device-authorization flow as orchestrated by OpenClaw. Phases 1–3 establish identity (the developer authenticates once, in a real browser, against Azure AD). Phases 4–5 perform service discovery (OpenClaw walks the ARM resource hierarchy, subscriptions → Foundry accounts → model deployments and persists the result to a local provider config). After registration, every model call OpenClaw makes against Foundry reuses the same Azure-CLI-managed token cache: tokens refresh transparently, and access is gated by the Foundry resource's RBAC assignments rather than a static API key. Dashed lines denote return values; the teal line in step 7 marks the single token-issuance event the rest of the system pivots on. Walking through the new flow: Start with the command to onboard openclaw as if you were setting up OpenClaw for the first time: openclaw onboard Kick things off with the OpenClaw onboard command, the same one you would use when setting up OpenClaw for the first time. When it prompts you, choose update values. Next, you will be asked to configure your models. Scroll down a little and you will see Microsoft Foundry listed as a supported provider. Pick it. From here, you have two options. You can sign in with an API key, which is what I covered in the previous blog post, or you can sign in through Azure AD. The Azure AD path is easier and more secure, so that is the one we will use. OpenClaw will give you a URL and a device code. Copy the URL into your browser and use the code to complete the sign in. (This is where the az CLI from the pre-requisite section earns its keep.) If everything worked, you should see a success prompt similar to this: Once you are signed in, OpenClaw will ask you to pick the Azure subscription that your Microsoft Foundry resource lives in. Pick the subscription, then pick the Foundry resource where your models are deployed. And that is pretty much it. All the models you have deployed to that Foundry resource get pulled into OpenClaw automatically. Compared to the old way of pasting API keys and endpoints one by one, this is a huge time saver, and you do not have to babysit any keys. From here you can start using your Foundry-deployed models inside OpenClaw straight away: Wrapping up The Azure AD sign-in option in OpenClaw is one of those small updates that quietly removes a real pain point. If you have ever juggled multiple Foundry endpoints and rotated keys across them, you already know why. With this flow, you sign in once, your models show up, and you can get back to actually building. If you have not tried OpenClaw with Microsoft Foundry yet, this is a good time to give it a go. And if you were holding off because of the key management overhead, that excuse is gone now. References Previous post on integrating Microsoft Foundry with OpenClaw using API keys: Integrating Microsoft Foundry with OpenClaw: Step by Step Model Configuration | Microsoft Community Hub Install the Azure CLI on Linux: https://learn.microsoft.com/en-us/cli/azure/install-azure-cli-linux?view=azure-cli-latest Install the Azure CLI on macOS: https://learn.microsoft.com/en-us/cli/azure/install-azure-cli-macos?view=azure-cli-latest#install-with-homebrew Homebrew formula for azure-cli: https://formulae.brew.sh/formula/azure-cliIntroducing OpenAI's newest chat model in Microsoft Foundry
OpenAI's GPT-5.5 Instant (or Chat-latest in the API) begins rolling out in Microsoft Foundry today as GPT-chat-latest. Built on GPT-5.4 and GPT-5.3-chat, the new model delivers measurable gains in factual accuracy, tool calling, and response efficiency. These improvements translate directly into more reliable production deployments. GPT-chat-latest is designed for the workflows builders are actually shipping: multi-turn assistants, agentic systems that orchestrate tools, and retrieval-grounded applications where precision and grounding matter as much as conversational quality. Why the name is changing In Microsoft Foundry, we are introducing GPT-chat-latest as the product name for this release, while the model continues to follow the existing Preview lifecycle and standard notice periods. We are also evaluating ways to simplify how customers access continuously updated models over time, but current behavior remains unchanged as that work continue Smarter, more factually reliable GPT-chat-latest closes the factuality gap from prior iterations with significant reductions in hallucinations, especially in domains where accuracy matters most. According to OpenAI, the new model produces 52.5% fewer hallucinations and reduces hallucinated claims by 37.3% on conversations previously flagged for factual errors when compared to GPT-5.3-chat. These gains extend beyond text. GPT-chat-latest shows improvements in visual reasoning, expert multimodal understanding, and STEM tasks, with measurable lifts across standard benchmarks: Benchmark GPT-5.3-chat GPT-chat-latest CharXiv-reasoning Scientific Chart Reasoning 75.0 81.6 MMMU-Pro Expert multimodal reasoning 69.2 76.0 GPQA PhD-level science questions 78.5 85.6 AIME 2025 Competition math 65.4 81.2 *Data shown comes from OpenAI’s testing” For builders shipping into regulated workloads such as clinical decision support, legal research, financial advisory, and technical analysis, these improvements raise the bar on the kinds of applications GPT-chat-latest can assist with. More efficient outputs GPT-chat-latest produces responses that may be more to-the-point without losing substance. The model may reduce verbosity and over formatting, ask fewer follow-up questions, and avoid cluttered output patterns that often require post-processing in production UIs. For builders, this can translate to two concrete benefits: lower output token costs at scale, and cleaner responses that drop into product surfaces with less downstream cleanup. In comparative testing from OpenAI, GPT-chat-latest produced roughly 25–30% fewer words than GPT-5.3-chat across a range of common prompts while preserving response quality, and in many cases improving it. Improving intelligence and tool calling GPT-chat-latest introduces measurable improvements in how the model interacts with tools, including better judgment about when and how to invoke them. The model produces more structured and context-aware tool invocation outputs, which is particularly relevant for workflows that rely on function calling, retrieval-augmented generation, and multi-step reasoning. Equally important, the model is better at deciding whether a tool is needed in the first place, reducing unnecessary tool calls in scenarios where it already has the information to answer directly. Improved search and context handling GPT-chat-latest includes targeted improvements to how the model retrieves, interprets, and synthesizes information when search is involved, with enhancements to query formulation, result ranking, and filtering, plus more grounded synthesis of retrieved content into final responses. These changes improve handling of ambiguous or underspecified queries and reduce noise in answers that depend on retrieved content. The model also makes better use of the context developers pass in, including system prompts, conversation history, retrieved documents, and structured data. Applications that maintain long-running state or stitch together multiple retrieval steps produce more coherent, context-aware outputs without developers having to over-engineer prompt scaffolding. Use Cases: When to choose the chat model Developers typically choose a chat-optimized model like GPT-5.5-chat when the application needs to sustain multi-turn conversations while reliably following instructions and coordinating external tools. This is a fit for assistants and agentic workflows where the model must interpret user intent over time, decide when to retrieve additional context, and produce structured outputs for downstream systems rather than just generate free-form text. Customer support and contact centers: virtual agents that maintain conversational context across a case, retrieve policy or product documentation via search, and hand off to a ticketing or CRM system through tool calls when escalation is needed. Retail and e-commerce: shopping and service assistants that clarify preferences over multiple turns, reference catalogs and policies via retrieval, and generate structured actions such as returns, exchanges, and order lookups through integrated tools. Manufacturing and field service: technician-facing assistants that combine conversational guidance with retrieval of manuals and work instructions, plus structured task creation in maintenance systems. Use GPT-chat-latest Use GPT-5.5 Reasoning Multi-turn assistants and customer-facing chat experiences Harder problems that benefit from more deliberate, step-by-step thinking Agentic workflows that coordinate tools (search, retrieval, ticketing, CRM) and benefit from structured tool outputs Complex analysis, planning, or decision support where correctness matters more than conversational flow Interactive experiences where you want quick back-and-forth clarification and task completion Tasks involving multi-constraint reasoning (policy interpretation, detailed requirements, long-horizon plans) RAG-based apps where the model must decide when to retrieve and then synthesize grounded answers Offline or low-tool scenarios where the main value is deeper reasoning over provided context Pricing Model Input ($/1M tokens) Cached input ($/1M tokens) Output ($/1M tokens) GPT-chat-latest $5 $0.50 $30 Responsible AI in Microsoft Foundry At Microsoft, our mission to empower people and organizations remains constant. In the age of AI, trust is foundational to adoption, and earning that trust requires a commitment to transparency, safety, and accountability. Microsoft Foundry provides governance controls, monitoring, and evaluation capabilities to help organizations deploy models responsibly in production environments, aligned with Microsoft's Responsible AI principles. Getting started GPT-chat-latest is rolling out in Microsoft Foundry today.
