Getting Started with Foundry Local: A Student Guide to the Microsoft Foundry Local Lab
If you want to start building AI applications on your own machine, the Microsoft Foundry Local Lab is one of the most useful places to begin. It is a practical workshop that takes you from first-time setup through to agents, retrieval, evaluation, speech transcription, tool calling, and a browser-based interface. The material is hands-on, cross-language, and designed to show how modern AI apps can run locally rather than depending on a cloud service for every step. This blog post is aimed at students, self-taught developers, and anyone learning how AI applications are put together in practice. Instead of treating large language models as a black box, the lab shows you how to install and manage local models, connect to them with code, structure tasks into workflows, and test whether the results are actually good enough. If you have been looking for a learning path that feels more like building real software and less like copying isolated snippets, this workshop is a strong starting point. What Is Foundry Local? Foundry Local is a local runtime for downloading, managing, and serving AI models on your own hardware. It exposes an OpenAI-compatible interface, which means you can work with familiar SDK patterns while keeping execution on your device. For learners, that matters for three reasons. First, it lowers the barrier to experimentation because you can run projects without setting up a cloud account for every test. Second, it helps you understand the moving parts behind AI applications, including model lifecycle, local inference, and application architecture. Third, it encourages privacy-aware development because the examples are designed to keep data on the machine wherever possible. The Foundry Local Lab uses that local-first approach to teach the full journey from simple prompts to multi-agent systems. It includes examples in Python, JavaScript, and C#, so you can follow the language that fits your course, your existing skills, or the platform you want to build on. Why This Lab Works Well for Learners A lot of AI tutorials stop at the moment a model replies to a prompt. That is useful for a first demo, but it does not teach you how to build a proper application. The Foundry Local Lab goes further. It is organised as a sequence of parts, each one adding a new idea and giving you working code to explore. You do not just ask a model to respond. You learn how to manage the service, choose a language SDK, construct retrieval pipelines, build agents, evaluate outputs, and expose the result through a usable interface. That sequence is especially helpful for students because the parts build on each other. Early labs focus on confidence and setup. Middle labs focus on architecture and patterns. Later labs move into more advanced ideas that are common in real projects, such as tool calling, evaluation, and custom model packaging. By the end, you have seen not just what a local AI app looks like, but how its different layers fit together. Before You Start The workshop expects a reasonably modern machine and at least one programming language environment. The core prerequisites are straightforward: install Foundry Local, clone the repository, and choose whether you want to work in Python, JavaScript, or C#. You do not need to master all three. In fact, most learners will get more value by picking one language first, completing the full path in that language, and only then comparing how the same patterns look elsewhere. If you are new to AI development, do not be put off by the number of parts. The early sections are accessible, and the later ones become much easier once you have completed the foundations. Think of the lab as a structured course rather than a single tutorial. What You Learn in Each Lab https://github.com/microsoft-foundry/foundry-local-lab Part 1: Getting Started with Foundry Local The first part introduces the basics of Foundry Local and gets you up and running. You learn how to install the CLI, inspect the model catalogue, download a model, and run it locally. This part also introduces practical details such as model aliases and dynamic service ports, which are small but important pieces of real development work. For students, the value of this part is confidence. You prove that local inference works on your machine, you see how the service behaves, and you learn the operational basics before writing any application code. By the end of Part 1, you should understand what Foundry Local does, how to start it, and how local model serving fits into an application workflow. Part 2: Foundry Local SDK Deep Dive Once the CLI makes sense, the workshop moves into the SDK. This part explains why application developers often use the SDK instead of relying only on terminal commands. You learn how to manage the service programmatically, browse available models, control model download and loading, and understand model metadata such as aliases and hardware-aware selection. This is where learners start to move from using a tool to building with a platform. You begin to see the difference between running a model manually and integrating it into software. By the end of this section, you should understand the API surface you will use in your own projects and know how to bootstrap the SDK in Python, JavaScript, or C#. Part 3: SDKs and APIs Part 3 turns the SDK concepts into a working chat application. You connect code to the local inference server and use the OpenAI-compatible API for streaming chat completions. The lab includes examples in all three supported languages, which makes it especially useful if you are comparing ecosystems or learning how the same idea is expressed through different syntax and libraries. The key learning outcome here is not just that you can get a response from a model. It is that you understand the boundary between your application and the local model service. You learn how messages are structured, how streaming works, and how to write the sort of integration code that becomes the foundation for every later lab. Part 4: Retrieval-Augmented Generation This is where the workshop starts to feel like modern AI engineering rather than basic prompting. In the retrieval-augmented generation lab, you build a simple RAG pipeline that grounds answers in supplied data. You work with an in-memory knowledge base, apply retrieval logic, score matches, and compose prompts that include grounded context. For learners, this part is important because it demonstrates a core truth of AI app development: a model on its own is often not enough. Useful applications usually need access to documents, notes, or structured information. By the end of Part 4, you understand why retrieval matters, how to pass retrieved context into a prompt, and how a pipeline can make answers more relevant and reliable. Part 5: Building AI Agents Part 5 introduces the concept of an agent. Instead of a one-off prompt and response, you begin to define behaviour through system instructions, roles, and conversation state. The lab uses the ChatAgent pattern and the Microsoft Agent Framework to show how an agent can maintain a purpose, respond with a persona, and return structured output such as JSON. This part helps learners understand the difference between a raw model call and a reusable application component. You learn how to design instructions that shape behaviour, how multi-turn interaction differs from single prompts, and why structured output matters when an AI component has to work inside a broader system. Part 6: Multi-Agent Workflows Once a single agent makes sense, the workshop expands the idea into a multi-agent workflow. The example pipeline uses roles such as researcher, writer, and editor, with outputs passed from one stage to the next. You explore sequential orchestration, shared configuration, and feedback loops between specialised components. For students, this lab is a very clear introduction to decomposition. Instead of asking one model to do everything at once, you break a task into smaller responsibilities. That pattern is useful well beyond AI. By the end of Part 6, you should understand why teams build multi-agent systems, how hand-offs are structured, and what trade-offs appear when more components are added to a workflow. Part 7: Zava Creative Writer Capstone Application The Zava Creative Writer is the capstone project that brings the earlier ideas together into a more production-style application. It uses multiple specialised agents, structured JSON hand-offs, product catalogue search, streaming output, and evaluation-style feedback loops. Rather than showing an isolated feature, this part shows how separate patterns combine into a complete system. This is one of the most valuable parts of the workshop for learner developers because it narrows the gap between tutorial code and real application design. You can see how orchestration, agent roles, and practical interfaces fit together. By the end of Part 7, you should be able to recognise the architecture of a serious local AI app and understand how the earlier labs support it. Part 8: Evaluation-Led Development Many beginner AI projects stop once the output looks good once or twice. This lab teaches a much stronger habit: evaluation-led development. You work with golden datasets, rule-based checks, and LLM-as-judge scoring to compare prompt or agent variants systematically. The goal is to move from anecdotal testing to repeatable assessment. This matters enormously for students because evaluation is one of the clearest differences between a classroom demo and dependable software. By the end of Part 8, you should understand how to define success criteria, compare outputs at scale, and use evidence rather than intuition when improving an AI component. Part 9: Voice Transcription with Whisper Part 9 broadens the workshop beyond text generation by introducing speech-to-text with Whisper running locally. You use the Foundry Local SDK to download and load the model, then transcribe local audio files through the compatible API surface. The emphasis is on privacy-first processing, with audio kept on-device. This section is a useful reminder that local AI development is not limited to chatbots. Learners see how a different modality fits into the same ecosystem and how local execution supports sensitive workloads. By the end of this lab, you should understand the transcription flow, the relevant client methods, and how speech features can be integrated into broader applications. Part 10: Using Custom or Hugging Face Models After learning the standard path, the workshop shows how to work with custom or Hugging Face models. This includes compiling models into optimised ONNX format with ONNX Runtime GenAI, choosing hardware-specific options, applying quantisation strategies, creating configuration files, and adding compiled models to the Foundry Local cache. For learner developers, this part opens the door to model engineering rather than simple model consumption. You begin to understand that model choice, optimisation, and packaging affect performance and usability. By the end of Part 10, you should have a clearer picture of how models move from an external source into a runnable local setup and why deployment format matters. Part 11: Tool Calling with Local Models Tool calling is one of the most practical patterns in current AI development, and this lab covers it directly. You define tool schemas, allow the model to request function calls, handle the multi-turn interaction loop, execute the tools locally, and return results back to the model. The examples include practical scenarios such as weather and population tools. This lab teaches learners how to move beyond generation into action. A model is no longer limited to producing text. It can decide when external data or a function is needed and incorporate that result into a useful answer. By the end of Part 11, you should understand the tool-calling flow and how AI systems connect reasoning with deterministic software behaviour. Part 12: Building a Web UI for the Zava Creative Writer Part 12 adds a browser-based front end to the capstone application. You learn how to serve a shared interface from Python, JavaScript, or C#, stream updates to the browser, consume NDJSON with the Fetch API and ReadableStream, and show live agent status as content is produced in real time. This part is especially good for students who want to build portfolio projects. It turns backend orchestration into something visible and interactive. By the end of Part 12, you should understand how to connect a local AI backend to a web interface and how streaming changes the user experience compared with waiting for one final response. Part 13: Workshop Complete The final part is a summary and extension point. It reviews what you have built across the previous sections and suggests ways to continue. Although it is not a new technical lab in the same way as the earlier parts, it plays an important role in learning. It helps you consolidate the architecture, the terminology, and the development patterns you have encountered. For learners, reflection matters. By the end of Part 13, you should be able to describe the full stack of a local AI application, from model management to user interface, and identify which area you want to deepen next. What Students Gain from the Full Workshop Taken together, these labs do more than teach Foundry Local itself. They teach how AI applications are built. You learn operational basics such as model setup and service management. You learn application integration through SDKs and APIs. You learn system design through RAG, agents, multi-agent orchestration, and web interfaces. You learn engineering discipline through evaluation. You also see how text, speech, custom models, and tool calling all fit into one local-first development workflow. That breadth makes the workshop useful in several settings. A student can use it as a self-study path. A lecturer can use it as source material for practical sessions. A learner developer can use it to build portfolio pieces and to understand which AI patterns are worth learning next. Because the repository includes Python, JavaScript, and C#, it also works well for comparing how architectural ideas transfer across languages. How to Approach the Lab as a Beginner If you are starting from scratch, the best route is simple. Complete Parts 1 to 3 in your preferred language first. That gives you the essential setup and integration skills. Then move into Parts 4 to 6 to understand how AI application patterns are composed. After that, use Parts 7 and 8 to learn how larger systems and evaluation fit together. Finally, explore Parts 9 to 12 based on your interests, whether that is speech, tooling, model customisation, or front-end work. It is also worth keeping notes as you go. Record what each part adds to your understanding, what code files matter, and what assumptions each example makes. That habit will help you move from following the labs to adapting the patterns in your own projects. Final Thoughts The Microsoft Foundry Local Lab is a strong introduction to local AI development because it treats learners like developers rather than spectators. You install, run, connect, orchestrate, evaluate, and present working systems. That makes it far more valuable than a short demo that only proves a model can answer a question. If you are a student or learner developer who wants to understand how AI applications are really built, this lab gives you a clear path. Start with the basics, pick one language, and work through the parts in order. By the time you finish, you will not just have used Foundry Local. You will have a practical foundation for building local AI applications with far more confidence and much better judgement.Build an Offline Hybrid RAG Stack with ONNX and Foundry Local
If you are building local AI applications, basic retrieval augmented generation is often only the starting point. This sample shows a more practical pattern: combine lexical retrieval, ONNX based semantic embeddings, and a Foundry Local chat model so the assistant stays grounded, remains offline, and degrades cleanly when the semantic path is unavailable. Why this sample is worth studying Many local RAG samples rely on a single retrieval strategy. That is usually enough for a proof of concept, but it breaks down quickly in production. Exact keywords, acronyms, and document codes behave differently from natural language questions and paraphrased requests. This repository keeps the original lexical retrieval path, adds local ONNX embeddings for semantic search, and fuses both signals in a hybrid ranking mode. The generation step runs through Foundry Local, so the entire assistant can remain on device. Lexical mode handles exact terms and structured vocabulary. Semantic mode handles paraphrases and more natural language phrasing. Hybrid mode combines both and is usually the best default. Lexical fallback protects the user experience if the embedding pipeline cannot start. Architectural overview The sample has two main flows: an offline ingestion pipeline and a local query pipeline. The architecture splits cleanly into offline ingestion at the top and runtime query handling at the bottom. Offline ingestion pipeline Read Markdown files from docs/ . Parse front matter and split each document into overlapping chunks. Generate dense embeddings when the ONNX model is available. Store chunks in SQLite with both sparse lexical features and optional dense vectors. Local query pipeline The browser posts a question to the Express API. ChatEngine resolves the requested retrieval mode. VectorStore retrieves lexical, semantic, or hybrid results. The prompt is assembled with the retrieved context and sent to a Foundry Local chat model. The answer is returned with source references and retrieval metadata. The sequence diagram shows the difference between lexical retrieval and hybrid retrieval. In hybrid mode, the query is embedded first, then lexical and semantic scores are fused before prompt assembly. Repository structure and core components The implementation is compact and readable. The main files to understand are listed below. src/config.js : retrieval defaults, paths, and model settings. src/embeddingEngine.js : local ONNX embedding generation through Transformers.js. src/vectorStore.js : SQLite storage plus lexical, semantic, and hybrid ranking. src/chatEngine.js : retrieval mode resolution, prompt assembly, and Foundry Local model execution. src/ingest.js : document ingestion and embedding generation during indexing. src/server.js : REST endpoints, streaming endpoints, upload support, and health reporting. Getting started To run the sample, you need Node.js 20 or newer, Foundry Local, and a local ONNX embedding model. The default model path is models/embeddings/bge-small-en-v1.5 . cd c:\Users\leestott\local-hybrid-retrival-onnx npm install huggingface-cli download BAAI/bge-small-en-v1.5 --local-dir models/embeddings/bge-small-en-v1.5 npm run ingest npm start Ingestion writes the local SQLite database to data/rag.db . If the embedding model is available, each chunk gets a dense vector as well as lexical features. If the embedding model is missing, ingestion still succeeds and the application remains usable in lexical mode. Best practice: local AI applications should treat model files, SQLite data, and native runtime compatibility as part of the deployable system, not as optional developer conveniences. Code walkthrough 1. Retrieval configuration The sample makes its retrieval behaviour explicit in configuration. That is useful for testing and for operator visibility. export const config = { model: "phi-3.5-mini", docsDir: path.join(ROOT, "docs"), dbPath: path.join(ROOT, "data", "rag.db"), chunkSize: 200, chunkOverlap: 25, topK: 3, retrievalMode: process.env.RETRIEVAL_MODE || "hybrid", retrievalModes: ["lexical", "semantic", "hybrid"], fallbackRetrievalMode: "lexical", retrievalWeights: { lexical: 0.45, semantic: 0.55, }, }; Those defaults tell you a lot about the intended operating profile. Chunks are small, the number of returned chunks is low, and the fallback path is explicit. 2. Local ONNX embeddings The embedding engine disables remote model loading and only uses local files. That matters for privacy, repeatability, and air gapped operation. env.allowLocalModels = true; env.allowRemoteModels = false; this.extractor = await pipeline("feature-extraction", resolvedPath, { local_files_only: true, }); const output = await this.extractor(text, { pooling: "mean", normalize: true, }); The mean pooling and normalisation step make the vectors suitable for cosine similarity based ranking. 3. Hybrid storage and ranking in SQLite Instead of adding a separate vector database, the sample stores lexical and semantic representations in the same SQLite table. That keeps the local footprint low and the implementation easy to debug. searchHybrid(query, queryEmbedding, topK = 5, weights = { lexical: 0.45, semantic: 0.55 }) { const lexicalResults = this.searchLexical(query, topK * 3); const semanticResults = this.searchSemantic(queryEmbedding, topK * 3); if (semanticResults.length === 0) { return lexicalResults.slice(0, topK).map((row) => ({ ...row, retrievalMode: "lexical", })); } const fused = [...combined.values()].map((row) => ({ ...row, score: (row.lexicalScore * lexicalWeight) + (row.semanticScore * semanticWeight), })); fused.sort((a, b) => b.score - a.score); return fused.slice(0, topK); } The important point is not just the weighted fusion. It is the fallback behaviour. If semantic retrieval cannot provide results, the user still gets lexical grounding instead of an empty context window. 4. Retrieval mode resolution in ChatEngine ChatEngine keeps the runtime behaviour predictable. It validates the requested mode and falls back to lexical search when semantic retrieval is unavailable. resolveRetrievalMode(requestedMode) { const desiredMode = config.retrievalModes.includes(requestedMode) ? requestedMode : config.retrievalMode; if ((desiredMode === "semantic" || desiredMode === "hybrid") && !this.semanticAvailable) { return config.fallbackRetrievalMode; } return desiredMode; } This is a sensible production design because local runtime failures are common. Missing model files or native dependency mismatches should reduce quality, not crash the entire assistant. 5. Foundry Local model management The sample uses FoundryLocalManager to discover, download, cache, and load the configured chat model. const manager = FoundryLocalManager.create({ appName: "gas-field-local-rag" }); const catalog = manager.catalog; this.model = await catalog.getModel(config.model); if (!this.model.isCached) { await this.model.download((progress) => { const pct = Math.round(progress * 100); this._emitStatus("download", `Downloading ${this.modelAlias}... ${pct}%`, progress); }); } await this.model.load(); this.chatClient = this.model.createChatClient(); this.chatClient.settings.temperature = 0.1; This gives the app a better local startup experience. The server can expose a status stream while the model initialises in the background. User experience and screenshots The client is intentionally simple, which makes it useful during evaluation. You can switch retrieval mode, test questions quickly, and inspect the retrieved sources. The landing page exposes retrieval mode directly in the UI. That makes it easy to compare lexical, semantic, and hybrid behaviour during testing. The sources panel shows grounding evidence and retrieval scores, which is useful when validating whether better answers are coming from better retrieval or just model phrasing. Best practices for ONNX RAG and Foundry Local Keep lexical fallback alive. Exact identifiers and runtime failures both make this necessary. Persist sparse and dense features together where possible. It simplifies debugging and operational reasoning. Use small chunks and conservative topK values for local context budgets. Expose health and status endpoints so users can see when the model is still loading or embeddings are unavailable. Test retrieval quality separately from generation quality. Pin and validate native runtime dependencies, especially ONNX Runtime, before tuning prompts. Practical warning: this repository already shows why runtime validation matters. A local app can ingest documents successfully and still fail at model initialisation if the native runtime stack is misaligned. How this compares with RAG and CAG The strongest value in this sample comes from where it sits between a basic local RAG baseline and a curated CAG design. Dimension Classic local RAG This hybrid ONNX RAG sample CAG Context assembly Retrieve chunks at query time, often lexically, then inject them into the prompt. Retrieve chunks at query time with lexical, semantic, or fused scoring, then inject the strongest results into the prompt. Use a prepared or cached context pack instead of fresh retrieval for every request. Main strength Easy to implement and easy to explain. Better recall for paraphrases without giving up exact match behaviour or offline execution. Predictable prompts and low query time overhead. Main weakness Misses synonyms and natural language reformulations. More moving parts, larger local asset footprint, and native runtime compatibility to manage. Coverage depends on curation quality and goes stale more easily. Failure behaviour Weak retrieval leads to weak grounding. Semantic failure can degrade to lexical retrieval if designed properly, which this sample does. Prepared context can be too narrow for new or unexpected questions. Best fit Simple local assistants and proof of concept systems. Offline copilots and technical assistants that need stronger recall across varied phrasing. Stable workflows with tightly bounded, curated knowledge. Samples Related samples: - Foundry Local RAG - https://github.com/leestott/local-rag - Foundry Local CAG - https://github.com/leestott/local-cag - Foundry Local hybrid-retrival-onnx https://github.com/leestott/local-hybrid-retrival-onnx Specific benefits of this hybrid approach over classic RAG It captures paraphrased questions that lexical search would often miss. It still preserves exact match performance for codes, terms, and product names. It gives operators a controlled degradation path when the semantic stack is unavailable. It stays local and inspectable without introducing a separate hosted vector service. Specific differences from CAG CAG shifts effort into context curation before the request. This sample retrieves evidence dynamically at runtime. CAG can be faster for fixed workflows, but it is usually less flexible when the document set changes. This hybrid RAG design is better suited to open ended knowledge search and growing document collections. What to validate before shipping Measure retrieval quality in each mode using exact term, acronym, and paraphrase queries. Check that sources shown in the UI reflect genuinely distinct evidence, not repeated chunks. Confirm the application remains usable when semantic retrieval is unavailable. Verify ONNX Runtime compatibility on the real target machines, not only on the development laptop. Test model download, cache, and startup behaviour with a clean environment. Final take For developers getting started with ONNX RAG and Foundry Local, this sample is a good technical reference because it demonstrates a realistic local architecture rather than a minimal demo. It shows how to build a grounded assistant that remains offline, supports multiple retrieval modes, and fails gracefully. Compared with classic local RAG, the hybrid design provides better recall and better resilience. Compared with CAG, it remains more flexible for changing document sets and less dependent on pre curated context packs. If you want a practical starting point for offline grounded AI on developer workstations or edge devices, this is the most balanced pattern in the repository set.Microsoft Olive & Olive Recipes: A Practical Guide to Model Optimization for Real-World Deployment
Why your model runs great on your laptop but fails in the real world You have trained a model. It scores well on your test set. It runs fine on your development machine with a beefy GPU. Then someone asks you to deploy it to a customer's edge device, a cloud endpoint with a latency budget, or a laptop with no discrete GPU at all. Suddenly the model is too large, too slow, or simply incompatible with the target runtime. You start searching for quantisation scripts, conversion tools, and hardware-specific compiler flags. Each target needs a different recipe, and the optimisation steps interact in ways that are hard to predict. This is the deployment gap. It is not a knowledge gap; it is a tooling gap. And it is exactly the problem that Microsoft Olive is designed to close. What is Olive? Olive is an easy-to-use, hardware-aware model optimisation toolchain that composes techniques across model compression, optimisation, and compilation. Rather than asking you to string together separate conversion scripts, quantisation utilities, and compiler passes by hand, Olive lets you describe what you have and what you need, then handles the pipeline. In practical terms, Olive takes a model source, such as a PyTorch model or an ONNX model (and other supported formats), plus a configuration that describes your production requirements and target hardware accelerator. It then runs the appropriate optimisation passes and produces a deployment-ready artefact. You can think of it as a build system for model optimisation: you declare the intent, and Olive figures out the steps. Official repo: github.com/microsoft/olive Documentation: microsoft.github.io/Olive Key advantages: why Olive matters for your workflow A. Optimise once, deploy across many targets One of the hardest parts of deploying models in production is that "production" is not one thing. Your model might need to run on a cloud GPU, an edge CPU, or a Windows device with an NPU. Each target has different memory constraints, instruction sets, and runtime expectations. Olive supports targeting CPU, GPU, and NPU through its optimisation workflow. This means a single toolchain can produce optimised artefacts for multiple deployment targets, expanding the number of platforms you can serve without maintaining separate optimisation scripts for each one. The conceptual workflow is straightforward: Olive can download, convert, quantise, and optimise a model using an auto-optimisation style approach where you specify the target device (cpu, gpu, or npu). This keeps the developer experience consistent even as the underlying optimisation strategy changes per target. B. ONNX as the portability layer If you have heard of ONNX but have not used it in anger, here is why it matters: ONNX gives your model a common representation that multiple runtimes understand. Instead of being locked to one framework's inference path, an ONNX model can run through ONNX Runtime and take advantage of whatever hardware is available. Olive supports ONNX conversion and optimisation, and can generate a deployment-ready model package along with sample inference code in languages like C#, C++, or Python. That package is not just the model weights; it includes the configuration and code needed to load and run the model on the target platform. For students and early-career engineers, this is a meaningful capability: you can train in PyTorch (the ecosystem you already know) and deploy through ONNX Runtime (the ecosystem your production environment needs). C. Hardware-specific acceleration and execution providers When Olive targets a specific device, it does not just convert the model format. It optimises for the execution provider (EP) that will actually run the model on that hardware. Execution providers are the bridge between the ONNX Runtime and the underlying accelerator. Olive can optimise for a range of execution providers, including: Vitis AI EP (AMD) – for AMD accelerator hardware OpenVINO EP (Intel) – for Intel CPUs, integrated GPUs, and VPUs QNN EP (Qualcomm) – for Qualcomm NPUs and SoCs DirectML EP (Windows) – for broad GPU support on Windows devices Why does EP targeting matter? Because the difference between a generic model and one optimised for a specific execution provider can be significant in terms of latency, throughput, and power efficiency. On battery-powered devices especially, the right EP optimisation can be the difference between a model that is practical and one that drains the battery in minutes. D. Quantisation and precision options Quantisation is one of the most powerful levers you have for making models smaller and faster. The core idea is reducing the numerical precision of model weights and activations: FP32 (32-bit floating point) – full precision, largest model size, highest fidelity FP16 (16-bit floating point) – roughly half the memory, usually minimal quality loss for most tasks INT8 (8-bit integer) – significant size and speed gains, moderate risk of quality degradation depending on the model INT4 (4-bit integer) – aggressive compression for the most constrained deployment scenarios Think of these as a spectrum. As you move from FP32 towards INT4, models get smaller and faster, but you trade away some numerical fidelity. The practical question is always: how much quality can I afford to lose for this use case? Practical heuristics for choosing precision: FP16 is often a safe default for GPU deployment. In practice, you might start here and only go lower if you need to. INT8 is a strong choice for CPU-based inference where memory and compute are constrained but accuracy requirements are still high (e.g., classification, embeddings, many NLP tasks). INT4 is worth exploring when you are deploying large language models to edge or consumer devices and need aggressive size reduction. Expect to validate quality carefully, as some tasks and model architectures tolerate INT4 better than others. Olive handles the mechanics of applying these quantisation passes as part of the optimisation pipeline, so you do not need to write custom quantisation scripts from scratch. Showcase: model conversion stories To make this concrete, here are three plausible optimisation scenarios that illustrate how Olive fits into real workflows. Story 1: PyTorch classification model → ONNX → quantised for cloud CPU inference Starting point: A PyTorch image classification model fine-tuned on a domain-specific dataset. Target hardware: Cloud CPU instances (no GPU budget for inference). Optimisation intent: Reduce latency and cost by quantising to INT8 whilst keeping accuracy within acceptable bounds. Output: An ONNX model optimised for CPU execution, packaged with configuration and sample inference code ready for deployment behind an API endpoint. Story 2: Hugging Face language model → optimised for edge NPU Starting point: A Hugging Face transformer model used for text summarisation. Target hardware: A laptop with an integrated NPU (e.g., a Qualcomm-based device). Optimisation intent: Shrink the model to INT4 to fit within NPU memory limits, and optimise for the QNN execution provider to leverage the neural processing unit. Output: A quantised ONNX model configured for QNN EP, with packaging that includes the model, runtime configuration, and sample code for local inference. Story 3: Same model, two targets – GPU vs. NPU Starting point: A single PyTorch generative model used for content drafting. Target hardware: (A) Cloud GPU for batch processing, (B) On-device NPU for interactive use. Optimisation intent: For GPU, optimise at FP16 for throughput. For NPU, quantise to INT4 for size and power efficiency. Output: Two separate optimised packages from the same source model, one targeting DirectML EP for GPU, one targeting QNN EP for NPU, each with appropriate precision, runtime configuration, and sample inference code. In each case, Olive handles the multi-step pipeline: conversion, optimisation passes, quantisation, and packaging. The developer's job is to define the target and validate the output quality. Introducing Olive Recipes If you are new to model optimisation, staring at a blank configuration file can be intimidating. That is where Olive Recipes comes in. The Olive Recipes repository complements Olive by providing recipes that demonstrate features and use cases. You can use them as a reference for optimising publicly available models or adapt them for your own proprietary models. The repository also includes a selection of ONNX-optimised models that you can study or use as starting points. Think of recipes as worked examples: each one shows a complete optimisation pipeline for a specific scenario, including the configuration, the target hardware, and the expected output. Instead of reinventing the pipeline from scratch, you can find a recipe close to your use case and modify it. For students especially, recipes are a fast way to learn what good optimisation configurations look like in practice. Taking it further: adding custom models to Foundry Local Once you have optimised a model with Olive, you may want to serve it locally for development, testing, or fully offline use. Foundry Local is a lightweight runtime that downloads, manages, and serves language models entirely on-device via an OpenAI-compatible API, with no cloud dependency and no API keys required. Important: Foundry Local only supports specific model templates. At present, these are the chat template (for conversational and text-generation models) and the whisper template (for speech-to-text models based on the Whisper architecture). If your model does not fit one of these two templates, it cannot currently be loaded into Foundry Local. Compiling a Hugging Face model for Foundry Local If your optimised model uses a supported architecture, you can compile it from Hugging Face for use with Foundry Local. The high-level process is: Choose a compatible Hugging Face model. The model must match one of Foundry Local's supported templates (chat or whisper). For chat models, this typically means decoder-only transformer architectures that support the standard chat format. Use Olive to convert and optimise. Olive handles the conversion from the Hugging Face source format into an ONNX-based, quantised artefact that Foundry Local can serve. This is where your Olive skills directly apply. Register the model with Foundry Local. Once compiled, you register the model so that Foundry Local's catalogue recognises it and can serve it through the local API. For the full step-by-step guide, including exact commands and configuration details, refer to the official documentation: How to compile Hugging Face models for Foundry Local. For a hands-on lab that walks through the complete workflow, see Foundry Local Lab, specifically Lab 10 which covers bringing custom models into Foundry Local. Why does this matter? The combination of Olive and Foundry Local gives you a complete local workflow: optimise your model with Olive, then serve it with Foundry Local for rapid iteration, privacy-sensitive workloads, or environments without internet connectivity. Because Foundry Local exposes an OpenAI-compatible API, your application code can switch between local and cloud inference with minimal changes. Keep in mind the template constraint. If you are planning to bring a custom model into Foundry Local, verify early that it fits the chat or whisper template. Attempting to load an unsupported architecture will not work, regardless of how well the model has been optimised. Contributing: how to get involved The Olive ecosystem is open source, and contributions are welcome. There are two main ways to contribute: A. Contributing recipes If you have built an optimisation pipeline that works well for a specific model, hardware target, or use case, consider contributing it as a recipe. Recipes are repeatable pipeline configurations that others can learn from and adapt. B. Sharing optimised model outputs and configurations If you have produced an optimised model that might be useful to others, sharing the optimisation configuration and methodology (and, where licensing permits, the model itself) helps the community build on proven approaches rather than starting from zero. Contribution checklist Reproducibility: Can someone else run your recipe or configuration and get comparable results? Licensing: Are the base model weights, datasets, and any dependencies properly licensed for sharing? Hardware target documented: Have you specified which device and execution provider the optimisation targets? Runtime documented: Have you noted the ONNX Runtime version and any EP-specific requirements? Quality validation: Have you included at least a basic accuracy or quality check for the optimised output? If you are a student or early-career developer, contributing a recipe is a great way to build portfolio evidence that you understand real deployment concerns, not just training. Try it yourself: a minimal workflow Here is a conceptual walkthrough of the optimisation workflow using Olive. The idea is to make the mental model concrete. For exact CLI flags and options, refer to the official Olive documentation. Choose a model source. Start with a PyTorch or Hugging Face model you want to optimise. This is your input. Choose a target device. Decide where the model will run: cpu , gpu , or npu . Choose an execution provider. Pick the EP that matches your hardware, for example DirectML for Windows GPU, QNN for Qualcomm NPU, or OpenVINO for Intel. Choose a precision. Select the quantisation level: fp16 , int8 , or int4 , based on your size, speed, and quality requirements. Run the optimisation. Olive will convert, quantise, optimise, and package the model for your target. The output is a deployment-ready artefact with model files, configuration, and sample inference code. A conceptual command might look like this: # Conceptual example – refer to official docs for exact syntax olive auto-opt --model-id my-model --device cpu --provider onnxruntime --precision int8 After optimisation, validate the output. Run your evaluation benchmark on the optimised model and compare quality, latency, and model size against the original. If INT8 drops quality below your threshold, try FP16. If the model is still too large for your device, explore INT4. Iteration is expected. Key takeaways Olive bridges training and deployment by providing a single, hardware-aware optimisation toolchain that handles conversion, quantisation, optimisation, and packaging. One source model, many targets: Olive lets you optimise the same model for CPU, GPU, and NPU, expanding your deployment reach without maintaining separate pipelines. ONNX is the portability layer that decouples your training framework from your inference runtime, and Olive leverages it to generate deployment-ready packages. Precision is a design choice: FP16, INT8, and INT4 each serve different deployment constraints. Start conservative, measure quality, and compress further only when needed. Olive Recipes are your starting point: Do not build optimisation pipelines from scratch when worked examples exist. Learn from recipes, adapt them, and contribute your own. Foundry Local extends the workflow: Once your model is optimised, Foundry Local can serve it on-device via a standard API, but only if it fits a supported template (chat or whisper). Resources Microsoft Olive – GitHub repository Olive documentation Olive Recipes – GitHub repository How to compile Hugging Face models for Foundry Local Foundry Local Lab – hands-on labs (see Lab 10 for custom models) Foundry Local documentationBuild a Fully Offline RAG App with Foundry Local: No Cloud Required
A practical guide to building an on-device AI support agent using Retrieval-Augmented Generation, JavaScript, and Microsoft Foundry Local. The Problem: AI That Can't Go Offline Most AI-powered applications today are firmly tethered to the cloud. They assume stable internet, low-latency API calls, and the comfort of a managed endpoint. But what happens when your users are in an environment with zero connectivity a gas pipeline in a remote field, a factory floor, an underground facility? That's exactly the scenario that motivated this project: a fully offline RAG-powered support agent that runs entirely on a laptop. No cloud. No API keys. No outbound network calls. Just a local model, a local vector store, and domain-specific documents all accessible from a browser on any device. The Gas Field Support Agent - running entirely on-device What is RAG and Why Should You Care? Retrieval-Augmented Generation (RAG) is a pattern that makes language models genuinely useful for domain-specific tasks. Instead of hoping the model "knows" the answer from pre-training, you: Retrieve relevant chunks from your own documents Augment the model's prompt with those chunks as context Generate a response grounded in your actual data The result: fewer hallucinations, traceable answers, and an AI that works with your content. If you're building internal tools, customer support bots, field manuals, or knowledge bases, RAG is the pattern you want. Why fully offline? Data sovereignty, air-gapped environments, field operations, latency-sensitive workflows, and regulatory constraints all demand AI that doesn't phone home. Running everything locally gives you complete control over your data and eliminates any external dependency. The Tech Stack This project is deliberately simple — no frameworks, no build steps, no Docker: Layer Technology Why AI Model Foundry Local + Phi-3.5 Mini Runs locally, OpenAI-compatible API, no GPU needed Backend Node.js + Express Lightweight, fast, universally known Vector Store SQLite via better-sqlite3 Zero infrastructure, single file on disk Retrieval TF-IDF + cosine similarity No embedding model required, fully offline Frontend Single HTML file with inline CSS No build step, mobile-responsive, field-ready The total dependency footprint is just four npm packages: express , openai , foundry-local-sdk , and better-sqlite3 . Architecture Overview The system has five layers — all running on a single machine: Five-layer architecture: Client → Server → RAG Pipeline → Data → AI Model Client Layer — A single HTML file served by Express, with quick-action buttons and responsive chat Server Layer — Express.js handles API routes for chat (streaming + non-streaming), document upload, and health checks RAG Pipeline — The chat engine orchestrates retrieval and generation; the chunker handles TF-IDF vectorization Data Layer — SQLite stores document chunks and their TF-IDF vectors; source docs live as .md files AI Layer — Foundry Local runs Phi-3.5 Mini Instruct on CPU/NPU, exposing an OpenAI-compatible API Getting Started in 5 Minutes You need two prerequisites: Node.js 20+ — nodejs.org Foundry Local — Microsoft's on-device AI runtime: Terminal winget install Microsoft.FoundryLocal Then clone, install, ingest, and run: git clone https://github.com/leestott/local-rag.git cd local-rag npm install npm run ingest # Index the 20 gas engineering documents npm start # Start the server + Foundry Local Open http://127.0.0.1:3000 and start chatting. Foundry Local auto-downloads Phi-3.5 Mini (~2 GB) on first run. How the RAG Pipeline Works Let's trace what happens when a user asks: "How do I detect a gas leak?" RAG query flow: Browser → Server → Vector Store → Model → Streaming response Step 1: Document Ingestion Before any queries happen, npm run ingest reads every .md file from the docs/ folder, splits each into overlapping chunks (~200 tokens, 25-token overlap), computes a TF-IDF vector for each chunk, and stores everything in SQLite. Chunking example docs/01-gas-leak-detection.md → Chunk 1: "Gas Leak Detection – Safety Warnings: Ensure all ignition..." → Chunk 2: "...sources are eliminated. Step-by-step: 1. Perform visual..." → Chunk 3: "...inspection of all joints. 2. Check calibration date..." The overlap ensures no information falls between chunk boundaries — a critical detail in any RAG system. Step 2: Query → Retrieval When the user sends a question, the server converts it into a TF-IDF vector, compares it against every stored chunk using cosine similarity, and returns the top-K most relevant results. For 20 documents (~200 chunks), this executes in under 10ms. src/vectorStore.js /** Retrieve top-K most relevant chunks for a query. */ search(query, topK = 5) { const queryTf = termFrequency(query); const rows = this.db.prepare("SELECT * FROM chunks").all(); const scored = rows.map((row) => { const chunkTf = new Map(JSON.parse(row.tf_json)); const score = cosineSimilarity(queryTf, chunkTf); return { ...row, score }; }); scored.sort((a, b) => b.score - a.score); return scored.slice(0, topK).filter((r) => r.score > 0); } Step 3: Prompt Construction The retrieved chunks are injected into the prompt alongside system instructions: Prompt structure System: You are an offline gas field support agent. Safety-first... Context: [Chunk 1: Gas Leak Detection – Safety Warnings...] [Chunk 2: Gas Leak Detection – Step-by-step...] [Chunk 3: Purging Procedures – Related safety...] User: How do I detect a gas leak? Step 4: Generation + Streaming The prompt is sent to Foundry Local via the OpenAI-compatible API. The response streams back token-by-token through Server-Sent Events (SSE) to the browser: Safety-first response with structured guidance Expandable sources with relevance scores Foundry Local: Your Local AI Runtime Foundry Local is what makes the "offline" part possible. It's a runtime from Microsoft that runs small language models (SLMs) on CPU or NPU — no GPU required. It exposes an OpenAI-compatible API and manages model downloads, caching, and lifecycle automatically. The integration code is minimal if you've used the OpenAI SDK before, this will feel instantly familiar: src/chatEngine.js import { FoundryLocalManager } from "foundry-local-sdk"; import { OpenAI } from "openai"; // Start Foundry Local and load the model const manager = new FoundryLocalManager(); const modelInfo = await manager.init("phi-3.5-mini"); // Use the standard OpenAI client — pointed at the local endpoint const client = new OpenAI({ baseURL: manager.endpoint, apiKey: manager.apiKey, }); // Chat completions work exactly like the cloud API const stream = await client.chat.completions.create({ model: modelInfo.id, messages: [ { role: "system", content: "You are a helpful assistant." }, { role: "user", content: "How do I detect a gas leak?" } ], stream: true, }); Portability matters Because Foundry Local uses the OpenAI API format, any code you write here can be ported to Azure OpenAI or OpenAI's cloud API with a single config change. You're not locked in. Why TF-IDF Instead of Embeddings? Most RAG tutorials use embedding models for retrieval. We chose TF-IDF for this project because: Fully offline — no embedding model to download or run Zero latency — vectorization is instantaneous (just math on word frequencies) Good enough — for a curated collection of 20 domain-specific documents, TF-IDF retrieves the right chunks reliably Transparent — you can inspect the vocabulary and weights, unlike neural embeddings For larger collections (thousands of documents) or when semantic similarity matters more than keyword overlap, you'd swap in an embedding model. But for this use case, TF-IDF keeps the stack simple and dependency-free. Mobile-Responsive Field UI Field engineers use this app on phones and tablets often wearing gloves. The UI is designed for harsh conditions with a dark, high-contrast theme, large touch targets (minimum 48px), and horizontally scrollable quick-action buttons. Desktop view Mobile view The entire frontend is a single index.html file — no React, no build step, no bundler. This keeps the project accessible and easy to deploy anywhere. Runtime Document Upload Users can upload new documents without restarting the server. The upload endpoint receives markdown content, chunks it, computes TF-IDF vectors, and inserts the chunks into SQLite — all in memory, immediately available for retrieval. Drag-and-drop document upload with instant indexing Adapt This for Your Own Domain This project is a scenario sample designed to be forked and customized. Here's the three-step process: 1. Replace the Documents Delete the gas engineering docs in docs/ and add your own .md files with optional YAML front-matter: docs/my-procedure.md --- title: Troubleshooting Widget Errors category: Support id: KB-001 --- # Troubleshooting Widget Errors ...your content here... 2. Edit the System Prompt Open src/prompts.js and rewrite the instructions for your domain: src/prompts.js export const SYSTEM_PROMPT = `You are an offline support agent for [YOUR DOMAIN]. Rules: - Only answer using the retrieved context - If the answer isn't in the context, say so - Use structured responses: Summary → Details → Reference `; 3. Tune the Retrieval Adjust chunking and retrieval parameters in src/config.js : src/config.js export const config = { model: "phi-3.5-mini", chunkSize: 200, // smaller = more precise, less context per chunk chunkOverlap: 25, // prevents info from falling between chunks topK: 3, // chunks per query (more = richer context, slower) }; Extending to Multi-Agent Architectures Once you have a working RAG agent, the natural next step is multi-agent orchestration where specialized agents collaborate to handle complex workflows. With Foundry Local's OpenAI-compatible API, you can compose multiple agent roles on the same machine: Multi-agent concept // Each agent is just a different system prompt + RAG scope const agents = { safety: { prompt: safetyPrompt, docs: "safety/*.md" }, diagnosis: { prompt: diagnosisPrompt, docs: "faults/*.md" }, procedure: { prompt: procedurePrompt, docs: "procedures/*.md" }, }; // Router determines which agent handles the query function route(query) { if (query.match(/safety|warning|hazard/i)) return agents.safety; if (query.match(/fault|error|code/i)) return agents.diagnosis; return agents.procedure; } // Each agent uses the same Foundry Local model endpoint const response = await client.chat.completions.create({ model: modelInfo.id, messages: [ { role: "system", content: selectedAgent.prompt }, { role: "system", content: `Context:\n${retrievedChunks}` }, { role: "user", content: userQuery } ], stream: true, }); This pattern lets you build specialized agent pipelines a triage agent routes to the right specialist, each with its own document scope and system prompt, all running on the same local Foundry instance. For production multi-agent systems, explore Microsoft Foundry for cloud-scale orchestration when connectivity is available. Local-first, cloud-ready Start with Foundry Local for development and offline scenarios. When your agents need cloud scale, swap to Azure AI Foundry with the same OpenAI-compatible API your agent code stays the same. Key Takeaways 1 RAG = Retrieve + Augment + Generate Ground your AI in real documents — dramatically reducing hallucination and making answers traceable. 2 Foundry Local makes local AI accessible OpenAI-compatible API running on CPU/NPU. No GPU required. No cloud dependency. 3 TF-IDF + SQLite is viable For small-to-medium document collections, you don't need a dedicated vector database. 4 Same API, local or cloud Build locally with Foundry Local, deploy with Azure OpenAI — zero code changes. What's Next? Embedding-based retrieval — swap TF-IDF for a local embedding model for better semantic matching Conversation memory — persist chat history across sessions Multi-agent routing — specialized agents for safety, diagnostics, and procedures PWA packaging — make it installable as a standalone app on mobile devices Hybrid retrieval — combine keyword search with semantic embeddings for best results Get the code Clone the repo, swap in your own documents, and start building: git clone https://github.com/leestott/local-rag.git github.com/leestott/local-rag — MIT licensed, contributions welcome. Open source under the MIT License. Built with Foundry Local and Node.js.Agentic Code Fixing with GitHub Copilot SDK and Foundry Local
Introduction AI-powered coding assistants have transformed how developers write and review code. But most of these tools require sending your source code to cloud services, a non-starter for teams working with proprietary codebases, air-gapped environments, or strict compliance requirements. What if you could have an intelligent coding agent that finds bugs, fixes them, runs your tests, and produces PR-ready summaries, all without a single byte leaving your machine? The Local Repo Patch Agent demonstrates exactly this. By combining the GitHub Copilot SDK for agent orchestration with Foundry Local for on-device inference, this project creates a fully autonomous coding workflow that operates entirely on your hardware. The agent scans your repository, identifies bugs and code smells, applies fixes, verifies them through your test suite, and generates a comprehensive summary of all changes, completely offline and secure. This article explores the architecture behind this integration, walks through the key implementation patterns, and shows you how to run the agent yourself. Whether you're building internal developer tools, exploring agentic workflows, or simply curious about what's possible when you combine GitHub's SDK with local AI, this project provides a production-ready foundation to build upon. Why Local AI Matters for Code Analysis Cloud-based AI coding tools have proven their value—GitHub Copilot has fundamentally changed how millions of developers work. But certain scenarios demand local-first approaches where code never leaves the organisation's network. Consider these real-world constraints that teams face daily: Regulatory compliance: Financial services, healthcare, and government projects often prohibit sending source code to external services, even for analysis Intellectual property protection: Proprietary algorithms and trade secrets can't risk exposure through cloud API calls Air-gapped environments: Secure facilities and classified projects have no internet connectivity whatsoever Latency requirements: Real-time code analysis in IDEs benefits from zero network roundtrip Cost control: High-volume code analysis without per-token API charges The Local Repo Patch Agent addresses all these scenarios. By running the AI model on-device through Foundry Local and using the GitHub Copilot SDK for orchestration, you get the intelligence of agentic coding workflows with complete data sovereignty. The architecture proves that "local-first" doesn't mean "capability-limited." The Technology Stack Two core technologies make this architecture possible, working together through a clever integration called BYOK (Bring Your Own Key). Understanding how they complement each other reveals the elegance of the design. GitHub Copilot SDK The GitHub Copilot SDK provides the agent runtime, the scaffolding that handles planning, tool invocation, streaming responses, and the orchestration loop that makes agentic behaviour possible. Rather than managing raw LLM API calls, developers define tools (functions the agent can call) and system prompts, and the SDK handles everything else. Key capabilities the SDK brings to this project: Session management: Maintains conversation context across multiple agent interactions Tool orchestration: Automatically invokes defined tools when the model requests them Streaming support: Real-time response streaming for responsive user interfaces Provider abstraction: Works with any OpenAI-compatible API through the BYOK configuration Foundry Local Foundry Local brings Azure AI Foundry's model catalog to your local machine. It automatically selects the best available hardware acceleration—GPU, NPU, or CP, and exposes models through an OpenAI-compatible API on localhost. Models run entirely on-device with no telemetry or data transmission. For this project, Foundry Local provides: On-device inference: All AI processing happens locally, ensuring complete data privacy Dynamic port allocation: The SDK auto-detects the Foundry Local endpoint, eliminating configuration hassle Model flexibility: Swap between models like qwen2.5-coder-1.5b , phi-3-mini , or larger variants based on your hardware OpenAI API compatibility: Standard API format means the GitHub Copilot SDK works without modification The BYOK Integration The entire connection between the GitHub Copilot SDK and Foundry Local happens through a single configuration object. This BYOK (Bring Your Own Key) pattern tells the SDK to route all inference requests to your local model instead of cloud services: const session = await client.createSession({ model: modelId, provider: { type: "openai", // Foundry Local speaks OpenAI's API format baseUrl: proxyBaseUrl, // Streaming proxy → Foundry Local apiKey: manager.apiKey, wireApi: "completions", // Chat Completions API }, streaming: true, tools: [ /* your defined tools */ ], }); This configuration is the key insight: with one config object, you've redirected an entire agent framework to run on local hardware. No code changes to the SDK, no special adapters—just standard OpenAI-compatible API communication. Architecture Overview The Local Repo Patch Agent implements a layered architecture where each component has a clear responsibility. Understanding this flow helps when extending or debugging the system. ┌─────────────────────────────────────────────────────────┐ │ Your Terminal / Web UI │ │ npm run demo / npm run ui │ └──────────────┬──────────────────────────────────────────┘ │ ┌──────────────▼──────────────────────────────────────────┐ │ src/agent.ts (this project) │ │ │ │ ┌────────────────────────────┐ ┌──────────────────┐ │ │ │ GitHub Copilot SDK │ │ Agent Tools │ │ │ │ (CopilotClient) │ │ list_files │ │ │ │ BYOK → Foundry │ │ read_file │ │ │ └────────┬───────────────────┘ │ write_file │ │ │ │ │ run_command │ │ └────────────┼───────────────────────┴──────────────────┘ │ │ │ │ JSON-RPC │ ┌────────────▼─────────────────────────────────────────────┐ │ GitHub Copilot CLI (server mode) │ │ Agent orchestration layer │ └────────────┬─────────────────────────────────────────────┘ │ POST /v1/chat/completions (BYOK) ┌────────────▼─────────────────────────────────────────────┐ │ Foundry Local (on-device inference) │ │ Model: qwen2.5-coder-1.5b via ONNX Runtime │ │ Endpoint: auto-detected (dynamic port) │ └───────────────────────────────────────────────────────────┘ The data flow works as follows: your terminal or web browser sends a request to the agent application. The agent uses the GitHub Copilot SDK to manage the conversation, which communicates with the Copilot CLI running in server mode. The CLI, configured with BYOK, sends inference requests to Foundry Local running on localhost. Responses flow back up the same path, with tool invocations happening in the agent.ts layer. The Four-Phase Workflow The agent operates through a structured four-phase loop, each phase building on the previous one's output. This decomposition transforms what would be an overwhelming single prompt into manageable, verifiable steps. Phase 1: PLAN The planning phase scans the repository and produces a numbered fix plan. The agent reads every source and test file, identifies potential issues, and outputs specific tasks to address: // Phase 1 system prompt excerpt const planPrompt = ` You are a code analysis agent. Scan the repository and identify: 1. Bugs that cause test failures 2. Code smells and duplication 3. Style inconsistencies Output a numbered list of fixes, ordered by priority. Each item should specify: file path, line numbers, issue type, and proposed fix. `; The tools available during this phase are list_files and read_file —the agent explores the codebase without modifying anything. This read-only constraint prevents accidental changes before the plan is established. Phase 2: EDIT With a plan in hand, the edit phase applies each fix by rewriting affected files. The agent receives the plan from Phase 1 and systematically addresses each item: // Phase 2 adds the write_file tool const editTools = [ { name: "write_file", description: "Write content to a file, creating or overwriting it", parameters: { type: "object", properties: { path: { type: "string", description: "File path relative to repo root" }, content: { type: "string", description: "Complete file contents" } }, required: ["path", "content"] } } ]; The write_file tool is sandboxed to the demo-repo directory, path traversal attempts are blocked, preventing the agent from modifying files outside the designated workspace. Phase 3: VERIFY After making changes, the verification phase runs the project's test suite to confirm fixes work correctly. If tests fail, the agent attempts to diagnose and repair the issue: // Phase 3 adds run_command with an allowlist const allowedCommands = ["npm test", "npm run lint", "npm run build"]; const runCommandTool = { name: "run_command", description: "Execute a shell command (npm test, npm run lint, npm run build only)", execute: async (command: string) => { if (!allowedCommands.includes(command)) { throw new Error(`Command not allowed: ${command}`); } // Execute and return stdout/stderr } }; The command allowlist is a critical security measure. The agent can only run explicitly permitted commands—no arbitrary shell execution, no data exfiltration, no system modification. Phase 4: SUMMARY The final phase produces a PR-style Markdown report documenting all changes. This summary includes what was changed, why each change was necessary, test results, and recommended follow-up actions: ## Summary of Changes ### Bug Fix: calculateInterest() in account.js - **Issue**: Division instead of multiplication caused incorrect interest calculations - **Fix**: Changed `principal / annualRate` to `principal * (annualRate / 100)` - **Tests**: 3 previously failing tests now pass ### Refactor: Duplicate formatCurrency() removed - **Issue**: Identical function existed in account.js and transaction.js - **Fix**: Both files now import from utils.js - **Impact**: Reduced code duplication, single source of truth ### Test Results - **Before**: 6/9 passing - **After**: 9/9 passing This structured output makes code review straightforward, reviewers can quickly understand what changed and why without digging through diffs. The Demo Repository: Intentional Bugs The project includes a demo-repo directory containing a small banking utility library with intentional problems for the agent to find and fix. This provides a controlled environment to demonstrate the agent's capabilities. Bug 1: Calculation Error in calculateInterest() The account.js file contains a calculation bug that causes test failures: // BUG: should be principal * (annualRate / 100) function calculateInterest(principal, annualRate) { return principal / annualRate; // Division instead of multiplication! } This bug causes 3 of 9 tests to fail. The agent identifies it during the PLAN phase by correlating test failures with the implementation, then fixes it during EDIT. Bug 2: Code Duplication The formatCurrency() function is copy-pasted in both account.js and transaction.js, even though a canonical version exists in utils.js. This duplication creates maintenance burden and potential inconsistency: // In account.js (duplicated) function formatCurrency(amount) { return '$' + amount.toFixed(2); } // In transaction.js (also duplicated) function formatCurrency(amount) { return '$' + amount.toFixed(2); } // In utils.js (canonical, but unused) export function formatCurrency(amount) { return '$' + amount.toFixed(2); } The agent identifies this duplication during planning and refactors both files to import from utils.js, eliminating redundancy. Handling Foundry Local Streaming Quirks One technical challenge the project solves is Foundry Local's behaviour with streaming requests. As of version 0.5, Foundry Local can hang on stream: true requests. The project includes a streaming proxy that works around this limitation transparently. The Streaming Proxy The streaming-proxy.ts file implements a lightweight HTTP proxy that converts streaming requests to non-streaming, then re-encodes the single response as SSE (Server-Sent Events) chunks—the format the OpenAI SDK expects: // streaming-proxy.ts simplified logic async function handleRequest(req: Request): Promise { const body = await req.json(); // If it's a streaming chat completion, convert to non-streaming if (body.stream === true && req.url.includes('/chat/completions')) { body.stream = false; const response = await fetch(foundryEndpoint, { method: 'POST', body: JSON.stringify(body), headers: { 'Content-Type': 'application/json' } }); const data = await response.json(); // Re-encode as SSE stream for the SDK return createSSEResponse(data); } // Non-streaming and non-chat requests pass through unchanged return fetch(foundryEndpoint, req); } This proxy runs on port 8765 by default and sits between the GitHub Copilot SDK and Foundry Local. The SDK thinks it's talking to a streaming-capable endpoint, while the actual inference happens non-streaming. The conversion is transparent, no changes needed to SDK configuration. Text-Based Tool Call Detection Small on-device models like qwen2.5-coder-1.5b sometimes output tool calls as JSON text rather than using OpenAI-style function calling. The SDK won't fire tool.execution_start events for these text-based calls, so the agent includes a regex-based detector: // Pattern to detect tool calls in model output const toolCallPattern = /\{[\s\S]*"name":\s*"(list_files|read_file|write_file|run_command)"[\s\S]*\}/; function detectToolCall(text: string): ToolCall | null { const match = text.match(toolCallPattern); if (match) { try { return JSON.parse(match[0]); } catch { return null; } } return null; } This fallback ensures tool calls are captured regardless of whether the model uses native function calling or text output, keeping the dashboard's tool call counter and CLI log accurate. Security Considerations Running an AI agent that can read and write files and execute commands requires careful security design. The Local Repo Patch Agent implements multiple layers of protection: 100% local execution: No code, prompts, or responses leave your machine—complete data sovereignty Command allowlist: The agent can only run npm test , npm run lint , and npm run build —no arbitrary shell commands Path sandboxing: File tools are locked to the demo-repo/ directory; path traversal attempts like ../../../etc/passwd are rejected File size limits: The read_file tool rejects files over 256 KB, preventing memory exhaustion attacks Recursion limits: Directory listing caps at 20 levels deep, preventing infinite traversal These constraints demonstrate responsible AI agent design. The agent has enough capability to do useful work but not enough to cause harm. When extending this project for your own use cases, maintain similar principles, grant minimum necessary permissions, validate all inputs, and fail closed on unexpected conditions. Running the Agent Getting the Local Repo Patch Agent running on your machine takes about five minutes. The project includes setup scripts that handle prerequisites automatically. Prerequisites Before running the setup, ensure you have: Node.js 18 or higher: Download from nodejs.org (LTS version recommended) Foundry Local: Install via winget install Microsoft.FoundryLocal (Windows) or brew install foundrylocal (macOS) GitHub Copilot CLI: Follow the GitHub Copilot CLI install guide Verify your installations: node --version # Should print v18.x.x or higher foundry --version copilot --version One-Command Setup The easiest path uses the provided setup scripts that install dependencies, start Foundry Local, and download the AI model: # Clone the repository git clone https://github.com/leestott/copilotsdk_foundrylocal.git cd copilotsdk_foundrylocal # Windows (PowerShell) .\setup.ps1 # macOS / Linux chmod +x setup.sh ./setup.sh When setup completes, you'll see: ━━━ Setup complete! ━━━ You're ready to go. Run one of these commands: npm run demo CLI agent (terminal output) npm run ui Web dashboard (http://localhost:3000) Manual Setup If you prefer step-by-step control: # Install npm packages npm install cd demo-repo && npm install --ignore-scripts && cd .. # Start Foundry Local and download the model foundry service start foundry model run qwen2.5-coder-1.5b # Copy environment configuration cp .env.example .env # Run the agent npm run demo The first model download takes a few minutes depending on your connection. After that, the model runs from cache with no internet required. Using the Web Dashboard For a visual experience with real-time streaming, launch the web UI: npm run ui Open http://localhost:3000 in your browser. The dashboard provides: Phase progress sidebar: Visual indication of which phase is running, completed, or errored Live streaming output: Model responses appear in real-time via WebSocket Tool call log: Every tool invocation logged with phase context Phase timing table: Performance metrics showing how long each phase took Environment info: Current model, endpoint, and repository path at a glance Configuration Options The agent supports several environment variables for customisation. Edit the .env file or set them directly: Variable Default Description FOUNDRY_LOCAL_ENDPOINT auto-detected Override the Foundry Local API endpoint FOUNDRY_LOCAL_API_KEY auto-detected Override the API key FOUNDRY_MODEL qwen2.5-coder-1.5b Which model to use from the Foundry Local catalog FOUNDRY_TIMEOUT_MS 180000 (3 min) How long each agent phase can run before timing out FOUNDRY_NO_PROXY — Set to 1 to disable the streaming proxy PORT 3000 Port for the web dashboard Using Different Models To try a different model from the Foundry Local catalog: # Use phi-3-mini instead FOUNDRY_MODEL=phi-3-mini npm run demo # Use a larger model for higher quality (requires more RAM/VRAM) FOUNDRY_MODEL=qwen2.5-7b npm run demo Adjusting for Slower Hardware If you're running on CPU-only or limited hardware, increase the timeout to give the model more time per phase: # 5 minutes per phase instead of 3 FOUNDRY_TIMEOUT_MS=300000 npm run demo Troubleshooting Common Issues When things don't work as expected, these solutions address the most common problems: Problem Solution foundry: command not found Install Foundry Local—see Prerequisites section copilot: command not found Install GitHub Copilot CLI—see Prerequisites section Agent times out on every phase Increase FOUNDRY_TIMEOUT_MS (e.g., 300000 for 5 min). CPU-only machines are slower. Port 3000 already in use Set PORT=3001 npm run ui Model download is slow First download can take 5-10 min. Subsequent runs use the cache. Cannot find module errors Run npm install again, then cd demo-repo && npm install --ignore-scripts Tests still fail after agent runs The agent edits files in demo-repo/. Reset with git checkout demo-repo/ and run again. PowerShell blocks setup.ps1 Run Set-ExecutionPolicy -Scope Process Bypass first, then .\setup.ps1 Diagnostic Test Scripts The src/tests/ folder contains standalone scripts for debugging SDK and Foundry Local integration issues. These are invaluable when things go wrong: # Debug-level SDK event logging npx tsx src/tests/test-debug.ts # Test non-streaming inference (bypasses streaming proxy) npx tsx src/tests/test-nostream.ts # Raw fetch to Foundry Local (bypasses SDK entirely) npx tsx src/tests/test-stream-direct.ts # Start the traffic-inspection proxy npx tsx src/tests/test-proxy.ts These scripts isolate different layers of the stack, helping identify whether issues lie in Foundry Local, the streaming proxy, the SDK, or your application code. Key Takeaways BYOK enables local-first AI: A single configuration object redirects the entire GitHub Copilot SDK to use on-device inference through Foundry Local Phased workflows improve reliability: Breaking complex tasks into PLAN → EDIT → VERIFY → SUMMARY phases makes agent behaviour predictable and debuggable Security requires intentional design: Allowlists, sandboxing, and size limits constrain agent capabilities to safe operations Local models have quirks: The streaming proxy and text-based tool detection demonstrate how to work around on-device model limitations Real-time feedback matters: The web dashboard with WebSocket streaming makes agent progress visible and builds trust in the system The architecture is extensible: Add new tools, change models, or modify phases to adapt the agent to your specific needs Conclusion and Next Steps The Local Repo Patch Agent proves that sophisticated agentic coding workflows don't require cloud infrastructure. By combining the GitHub Copilot SDK's orchestration capabilities with Foundry Local's on-device inference, you get intelligent code analysis that respects data sovereignty completely. The patterns demonstrated here, BYOK integration, phased execution, security sandboxing, and streaming workarounds, transfer directly to production systems. Consider extending this foundation with: Custom tool sets: Add database queries, API calls to internal services, or integration with your CI/CD pipeline Multiple repository support: Scan and fix issues across an entire codebase or monorepo Different model sizes: Use smaller models for quick scans, larger ones for complex refactoring Human-in-the-loop approval: Add review steps before applying fixes to production code Integration with Git workflows: Automatically create branches and PRs from agent-generated fixes Clone the repository, run through the demo, and start building your own local-first AI coding tools. The future of developer AI isn't just cloud—it's intelligent systems that run wherever your code lives. Resources Local Repo Patch Agent Repository – Full source code with setup scripts and documentation Foundry Local – Official site for on-device AI inference Foundry Local GitHub Repository – Installation instructions and CLI reference Foundry Local Get Started Guide – Official Microsoft Learn documentation Foundry Local SDK Reference – Python and JavaScript SDK documentation GitHub Copilot SDK – Official SDK repository GitHub Copilot SDK BYOK Documentation – Bring Your Own Key integration guide GitHub Copilot SDK Getting Started – SDK setup and first agent tutorial Microsoft Sample: Copilot SDK + Foundry Local – Official integration sample from MicrosoftBuilding a Local Research Desk: Multi-Agent Orchestration
Introduction Multi-agent systems represent the next evolution of AI applications. Instead of a single model handling everything, specialised agents collaborate—each with defined responsibilities, passing context to one another, and producing results that no single agent could achieve alone. But building these systems typically requires cloud infrastructure, API keys, usage tracking, and the constant concern about what data leaves your machine. What if you could build sophisticated multi-agent workflows entirely on your local machine, with no cloud dependencies? The Local Research & Synthesis Desk demonstrates exactly this. Using Microsoft Agent Framework (MAF) for orchestration and Foundry Local for on-device inference, this demo shows how to create a four-agent research pipeline that runs entirely on your hardware—no API keys, no data leaving your network, and complete control over every step. This article walks through the architecture, implementation patterns, and practical code that makes multi-agent local AI possible. You'll learn how to bootstrap Foundry Local from Python, create specialised agents with distinct roles, wire them into sequential, concurrent, and feedback loop orchestration patterns, and implement tool calling for extended functionality. Whether you're building research tools, internal analysis systems, or simply exploring what's possible with local AI, this architecture provides a production-ready foundation. Why Multi-Agent Architecture Matters Single-agent AI systems hit limitations quickly. Ask one model to research a topic, analyse findings, identify gaps, and write a comprehensive report—and you'll get mediocre results. The model tries to do everything at once, with no opportunity for specialisation, review, or iterative refinement. Multi-agent systems solve this by decomposing complex tasks into specialised roles. Each agent focuses on what it does best: Planners break ambiguous questions into concrete sub-tasks Retrievers focus exclusively on finding and extracting relevant information Critics review work for gaps, contradictions, and quality issues Writers synthesise everything into coherent, well-structured output This separation of concerns mirrors how human teams work effectively. A research team doesn't have one person doing everything—they have researchers, fact-checkers, editors, and writers. Multi-agent AI systems apply the same principle to AI workflows, with each agent receiving the output of previous agents as context for their own specialised task. The Local Research & Synthesis Desk implements this pattern with four primary agents, plus an optional ToolAgent for utility functions. Here's how user questions flow through the system: This architecture demonstrates three essential orchestration patterns: sequential pipelines where each agent builds on the previous output, concurrent fan-out where independent tasks run in parallel to save time, and feedback loops where the Critic can send work back to the Retriever for iterative refinement. The Technology Stack: MAF + Foundry Local Before diving into implementation, let's understand the two core technologies that make this architecture possible and why they work so well together. Microsoft Agent Framework (MAF) The Microsoft Agent Framework provides building blocks for creating AI agents in Python and .NET. Unlike frameworks that require specific cloud providers, MAF works with any OpenAI-compatible API—which is exactly what Foundry Local provides. The key abstraction in MAF is the ChatAgent . Each agent has: Instructions: A system prompt that defines the agent's role and behaviour Chat client: An OpenAI-compatible client for making inference calls Tools: Optional functions the agent can invoke during execution Name: An identifier for logging and observability MAF handles message threading, tool execution, and response parsing automatically. You focus on designing agent behaviour rather than managing low-level API interactions. Foundry Local Foundry Local brings Azure AI Foundry's model catalog to your local machine. It automatically selects the best hardware acceleration available (GPU, NPU, or CPU) and exposes models through an OpenAI-compatible API. Models run entirely on-device with no data leaving your machine. The foundry-local-sdk Python package provides programmatic control over the Foundry Local service. You can start the service, download models, and retrieve connection information—all from your Python code. This is the "control plane" that manages the local AI infrastructure. The combination is powerful: MAF handles agent logic and orchestration, while Foundry Local provides the underlying inference. No cloud dependencies, no API keys, complete data privacy: Bootstrapping Foundry Local from Python The first practical challenge is starting Foundry Local programmatically. The FoundryLocalBootstrapper class handles this, encapsulating all the setup logic so the rest of the application can focus on agent behaviour. The bootstrap process follows three steps: start the Foundry Local service if it's not running, download the requested model if it's not cached, and return connection information that MAF agents can use. Here's the core implementation: from dataclasses import dataclass from foundry_local import FoundryLocalManager @dataclass class FoundryConnection: """Holds endpoint, API key, and model ID after bootstrap.""" endpoint: str api_key: str model_id: str model_alias: str This dataclass carries everything needed to connect MAF agents to Foundry Local. The endpoint is typically http://localhost:<port>/v1 (the port is assigned dynamically), and the API key is managed internally by Foundry Local. class FoundryLocalBootstrapper: def __init__(self, alias: str | None = None) -> None: self.alias = alias or os.getenv("MODEL_ALIAS", "qwen2.5-0.5b") def bootstrap(self) -> FoundryConnection: """Start service, download & load model, return connection info.""" from foundry_local import FoundryLocalManager manager = FoundryLocalManager() model_info = manager.download_and_load_model(self.alias) return FoundryConnection( endpoint=manager.endpoint, api_key=manager.api_key, model_id=model_info.id, model_alias=self.alias, ) Key design decisions in this implementation: Lazy import: The foundry_local import happens inside bootstrap() so the application can provide helpful error messages if the SDK isn't installed Environment configuration: Model alias comes from MODEL_ALIAS environment variable or defaults to qwen2.5-0.5b Automatic hardware selection: Foundry Local picks GPU, NPU, or CPU automatically—no configuration needed The qwen2.5 model family is recommended because it supports function/tool calling, which the ToolAgent requires. For higher quality outputs, larger variants like qwen2.5-7b or qwen2.5-14b are available via the --model flag. Creating Specialised Agents With Foundry Local bootstrapped, the next step is creating agents with distinct roles. Each agent is a ChatAgent instance with carefully crafted instructions that focus it on a specific task. The Planner Agent The Planner receives a user question and available documents, then breaks the research task into concrete sub-tasks. Its instructions emphasise structured output—a numbered list of specific tasks rather than prose: from agent_framework import ChatAgent from agent_framework.openai import OpenAIChatClient def _make_client(conn: FoundryConnection) -> OpenAIChatClient: """Create an MAF OpenAIChatClient pointing at Foundry Local.""" return OpenAIChatClient( api_key=conn.api_key, base_url=conn.endpoint, model_id=conn.model_id, ) def create_planner(conn: FoundryConnection) -> ChatAgent: return ChatAgent( chat_client=_make_client(conn), name="Planner", instructions=( "You are a planning agent. Given a user's research question and a list " "of document snippets (if any), break the question into 2-4 concrete " "sub-tasks. Output ONLY a numbered list of tasks. Each task should state:\n" " • What information is needed\n" " • Which source documents might help (if known)\n" "Keep it concise — no more than 6 lines total." ), ) Notice how the instructions are explicit about output format. Multi-agent systems work best when each agent produces structured, predictable output that downstream agents can parse reliably. The Retriever Agent The Retriever receives the Planner's task list plus raw document content, then extracts and cites relevant passages. Its instructions emphasise citation format—a specific pattern that the Writer can reference later: def create_retriever(conn: FoundryConnection) -> ChatAgent: return ChatAgent( chat_client=_make_client(conn), name="Retriever", instructions=( "You are a retrieval agent. You receive a research plan AND raw document " "text from local files. Your job:\n" " 1. Identify the most relevant passages for each task in the plan.\n" " 2. Output extracted snippets with citations in the format:\n" " [filename.ext, lines X-Y]: \"quoted text…\"\n" " 3. If no relevant content exists, say so explicitly.\n" "Be precise — quote only what is relevant, keep each snippet under 100 words." ), ) The citation format [filename.ext, lines X-Y] creates a consistent contract. The Writer knows exactly how to reference source material, and human reviewers can verify claims against original documents. The Critic Agent The Critic reviews the Retriever's work, identifying gaps and contradictions. This agent serves as a quality gate before the final report and can trigger feedback loops for iterative improvement: def create_critic(conn: FoundryConnection) -> ChatAgent: return ChatAgent( chat_client=_make_client(conn), name="Critic", instructions=( "You are a critical review agent. You receive a plan and extracted snippets. " "Your job:\n" " 1. Check for gaps — are any plan tasks unanswered?\n" " 2. Check for contradictions between snippets.\n" " 3. Suggest 1-2 specific improvements or missing details.\n" "Start your response with 'GAPS FOUND' if issues exist, or 'NO GAPS' if satisfied.\n" "Then output a short numbered list of issues (or say 'No issues found')." ), ) The Critic is instructed to output GAPS FOUND or NO GAPS at the start of its response. This structured output enables the orchestrator to detect when gaps exist and trigger the feedback loop—sending the gaps back to the Retriever for additional retrieval before re-running the Critic. This iterates up to 2 times before the Writer takes over, ensuring higher quality reports. Critics are essential for production systems. Without this review step, the Writer might produce confident-sounding reports with missing information or internal contradictions. The Writer Agent The Writer receives everything—original question, plan, extracted snippets, and critic review—then produces the final report: def create_writer(conn: FoundryConnection) -> ChatAgent: return ChatAgent( chat_client=_make_client(conn), name="Writer", instructions=( "You are the final report writer. You receive:\n" " • The original question\n" " • A plan, extracted snippets with citations, and a critic review\n\n" "Produce a clear, well-structured answer (3-5 paragraphs). " "Requirements:\n" " • Cite sources using [filename.ext, lines X-Y] notation\n" " • Address any gaps the critic raised (note if unresolvable)\n" " • End with a one-sentence summary\n" "Do NOT fabricate citations — only use citations provided by the Retriever." ), ) The final instruction—"Do NOT fabricate citations"—is crucial for responsible AI. The Writer has access only to citations the Retriever provided, preventing hallucinated references that plague single-agent research systems. Implementing Sequential Orchestration With agents defined, the orchestrator connects them into a workflow. Sequential orchestration is the simpler pattern: each agent runs after the previous one completes, passing its output as input to the next agent. The implementation uses Python's async/await for clean asynchronous execution: import asyncio import time from dataclasses import dataclass, field @dataclass class StepResult: """Captures one agent step for observability.""" agent_name: str input_text: str output_text: str elapsed_sec: float @dataclass class WorkflowResult: """Final result of the entire orchestration run.""" question: str steps: list[StepResult] = field(default_factory=list) final_report: str = "" async def _run_agent(agent: ChatAgent, prompt: str) -> tuple[str, float]: """Execute a single agent and measure elapsed time.""" start = time.perf_counter() response = await agent.run(prompt) elapsed = time.perf_counter() - start return response.content, elapsed The StepResult dataclass captures everything needed for observability: what went in, what came out, and how long it took. This information is invaluable for debugging and optimisation. The sequential pipeline chains agents together, building context progressively: async def run_sequential_workflow( question: str, docs: LoadedDocuments, conn: FoundryConnection, ) -> WorkflowResult: wf = WorkflowResult(question=question) doc_block = docs.combined_text if docs.chunks else "(no documents provided)" # Step 1 — Plan planner = create_planner(conn) planner_prompt = f"User question: {question}\n\nAvailable documents:\n{doc_block}" plan_text, elapsed = await _run_agent(planner, planner_prompt) wf.steps.append(StepResult("Planner", planner_prompt, plan_text, elapsed)) # Step 2 — Retrieve retriever = create_retriever(conn) retriever_prompt = f"Plan:\n{plan_text}\n\nDocuments:\n{doc_block}" snippets_text, elapsed = await _run_agent(retriever, retriever_prompt) wf.steps.append(StepResult("Retriever", retriever_prompt, snippets_text, elapsed)) # Step 3 — Critique critic = create_critic(conn) critic_prompt = f"Plan:\n{plan_text}\n\nExtracted snippets:\n{snippets_text}" critique_text, elapsed = await _run_agent(critic, critic_prompt) wf.steps.append(StepResult("Critic", critic_prompt, critique_text, elapsed)) # Step 4 — Write writer = create_writer(conn) writer_prompt = ( f"Original question: {question}\n\n" f"Plan:\n{plan_text}\n\n" f"Extracted snippets:\n{snippets_text}\n\n" f"Critic review:\n{critique_text}" ) report_text, elapsed = await _run_agent(writer, writer_prompt) wf.steps.append(StepResult("Writer", writer_prompt, report_text, elapsed)) wf.final_report = report_text return wf Each step receives all relevant context from previous steps. The Writer gets the most comprehensive prompt—original question, plan, snippets, and critique—enabling it to produce a well-informed final report. Adding Concurrent Fan-Out and Feedback Loops Sequential orchestration works well but can be slow. When tasks are independent—neither needs the other's output—running them in parallel saves time. The demo implements this with asyncio.gather . Consider the Retriever and ToolAgent: both need the Planner's output, but neither depends on the other. Running them concurrently cuts the wait time roughly in half: async def run_concurrent_retrieval( plan_text: str, docs: LoadedDocuments, conn: FoundryConnection, ) -> tuple[str, str]: """Run Retriever and ToolAgent in parallel.""" retriever = create_retriever(conn) tool_agent = create_tool_agent(conn) doc_block = docs.combined_text if docs.chunks else "(no documents)" retriever_prompt = f"Plan:\n{plan_text}\n\nDocuments:\n{doc_block}" tool_prompt = f"Analyse the following documents for word count and keywords:\n{doc_block}" # Execute both agents concurrently (snippets_text, r_elapsed), (tool_text, t_elapsed) = await asyncio.gather( _run_agent(retriever, retriever_prompt), _run_agent(tool_agent, tool_prompt), ) return snippets_text, tool_text The asyncio.gather function runs both coroutines concurrently and returns when both complete. If the Retriever takes 3 seconds and the ToolAgent takes 1.5 seconds, the total wait is approximately 3 seconds rather than 4.5 seconds. Implementing the Feedback Loop The most sophisticated orchestration pattern is the Critic–Retriever feedback loop. When the Critic identifies gaps in the retrieved information, the orchestrator sends them back to the Retriever for additional retrieval, then re-evaluates: async def run_critic_with_feedback( plan_text: str, snippets_text: str, docs: LoadedDocuments, conn: FoundryConnection, max_iterations: int = 2, ) -> tuple[str, str]: """ Run Critic with feedback loop to Retriever. Returns (final_snippets, final_critique). """ critic = create_critic(conn) retriever = create_retriever(conn) current_snippets = snippets_text for iteration in range(max_iterations): # Run Critic critic_prompt = f"Plan:\n{plan_text}\n\nExtracted snippets:\n{current_snippets}" critique_text, _ = await _run_agent(critic, critic_prompt) # Check if gaps were found if not critique_text.upper().startswith("GAPS FOUND"): return current_snippets, critique_text # Gaps found — send back to Retriever for more extraction gap_fill_prompt = ( f"Previous snippets:\n{current_snippets}\n\n" f"Gaps identified:\n{critique_text}\n\n" f"Documents:\n{docs.combined_text}\n\n" "Extract additional relevant passages to fill these gaps." ) additional_snippets, _ = await _run_agent(retriever, gap_fill_prompt) current_snippets = f"{current_snippets}\n\n--- Gap-fill iteration {iteration + 1} ---\n{additional_snippets}" # Max iterations reached — run final critique final_critique, _ = await _run_agent(critic, f"Plan:\n{plan_text}\n\nExtracted snippets:\n{current_snippets}") return current_snippets, final_critique This feedback loop pattern significantly improves output quality. The Critic acts as a quality gate, and when standards aren't met, the system iteratively improves rather than producing incomplete results. The full workflow combines all three patterns—sequential where dependencies require it, concurrent where independence allows it, and feedback loops for quality assurance: async def run_full_workflow( question: str, docs: LoadedDocuments, conn: FoundryConnection, ) -> WorkflowResult: """ End-to-end workflow showcasing THREE orchestration patterns: 1. Planner runs first (sequential — must happen before anything else). 2. Retriever + ToolAgent run concurrently (fan-out on independent tasks). 3. Critic reviews with feedback loop (iterates with Retriever if gaps found). 4. Writer produces final report (sequential — needs everything above). """ wf = WorkflowResult(question=question) # Step 1: Planner (sequential) plan_text, elapsed = await _run_agent(create_planner(conn), planner_prompt) wf.steps.append(StepResult("Planner", planner_prompt, plan_text, elapsed)) # Step 2: Concurrent fan-out (Retriever + ToolAgent) snippets_text, tool_text = await run_concurrent_retrieval(plan_text, docs, conn) # Step 3: Critic with feedback loop final_snippets, critique_text = await run_critic_with_feedback( plan_text, snippets_text, docs, conn ) # Step 4: Writer (sequential — needs everything) writer_prompt = ( f"Original question: {question}\n\n" f"Plan:\n{plan_text}\n\n" f"Snippets:\n{final_snippets}\n\n" f"Stats:\n{tool_text}\n\n" f"Critique:\n{critique_text}" ) report_text, elapsed = await _run_agent(create_writer(conn), writer_prompt) wf.final_report = report_text return wf This hybrid approach maximises both correctness and performance. Dependencies are respected, independent work happens in parallel, and quality is ensured through iterative feedback. Implementing Tool Calling Some agents benefit from deterministic tools rather than relying entirely on LLM generation. The ToolAgent demonstrates this pattern with two utility functions: word counting and keyword extraction. MAF supports tool calling through function declarations with Pydantic type annotations: from typing import Annotated from pydantic import Field def word_count( text: Annotated[str, Field(description="The text to count words in")] ) -> int: """Count words in a text string.""" return len(text.split()) def extract_keywords( text: Annotated[str, Field(description="The text to extract keywords from")], top_n: Annotated[int, Field(description="Number of keywords to return", default=5)] ) -> list[str]: """Extract most frequent words (simple implementation).""" words = text.lower().split() # Filter common words, count frequencies, return top N word_counts = {} for word in words: if len(word) > 3: # Skip short words word_counts[word] = word_counts.get(word, 0) + 1 sorted_words = sorted(word_counts.items(), key=lambda x: x[1], reverse=True) return [word for word, count in sorted_words[:top_n]] The Annotated type with Field descriptions provides metadata that MAF uses to generate function schemas for the LLM. When the model needs to count words, it invokes the word_count tool rather than attempting to count in its response (which LLMs notoriously struggle with). The ToolAgent receives these functions in its constructor: def create_tool_agent(conn: FoundryConnection) -> ChatAgent: return ChatAgent( chat_client=_make_client(conn), name="ToolHelper", instructions=( "You are a utility agent. Use the provided tools to compute " "word counts or extract keywords when asked. Return the tool " "output directly — do not embellish." ), tools=[word_count, extract_keywords], ) This pattern—combining LLM reasoning with deterministic tools—produces more reliable results. The LLM decides when to use tools and how to interpret results, but the actual computation happens in Python where precision is guaranteed. Running the Demo With the architecture explained, here's how to run the demo yourself. Setup takes about five minutes. Prerequisites You'll need Python 3.10 or higher and Foundry Local installed on your machine. Install Foundry Local by following the instructions at github.com/microsoft/Foundry-Local, then verify it works: foundry --help Installation Clone the repository and set up a virtual environment: git clone https://github.com/leestott/agentframework--foundrylocal.git cd agentframework--foundrylocal python -m venv .venv # Windows .venv\Scripts\activate # macOS / Linux source .venv/bin/activate pip install -r requirements.txt copy .env.example .env CLI Usage Run the research workflow from the command line: python -m src.app "What are the key features of Foundry Local and how does it compare to cloud inference?" --docs ./data You'll see agent-by-agent progress with timing information: Web Interface For a visual experience, launch the Flask-based web UI: python -m src.app.web Open http://localhost:5000 in your browser. The web UI provides real-time streaming of agent progress, a visual pipeline showing both orchestration patterns, and an interactive demos tab showcasing tool calling capabilities. CLI Options The CLI supports several options for customisation: --docs: Folder of local documents to search (default: ./data) --model: Foundry Local model alias (default: qwen2.5-0.5b) --mode: full for sequential + concurrent, or sequential for simpler pipeline --log-level: DEBUG, INFO, WARNING, or ERROR For higher quality output, try larger models: python -m src.app "Explain multi-agent benefits" --docs ./data --model qwen2.5-7b Validate Tool/Function Calling Run the dedicated tool calling demo to verify function calling works: python -m src.app.tool_demo This tests direct tool function calls ( word_count , extract_keywords ), LLM-driven tool calling via the ToolAgent, and multi-tool requests in a single prompt. Run Tests Run the smoke tests to verify your setup: pip install pytest pytest-asyncio pytest tests/ -v The smoke tests check document loading, tool functions, and configuration—they do not require a running Foundry Local service. Interactive Demos: Exploring MAF Capabilities Beyond the research workflow, the web UI includes five interactive demos showcasing different MAF capabilities. Each demonstrates a specific pattern with suggested prompts and real-time results. Weather Tools demonstrates multi-tool calling with an agent that provides weather information, forecasts, city comparisons, and activity recommendations. The agent uses four different tools to construct comprehensive responses. Math Calculator shows precise calculation through tool calling. The agent uses arithmetic, percentage, unit conversion, compound interest, and statistics tools instead of attempting mental math—eliminating the calculation errors that plague LLM-only approaches. Sentiment Analyser performs structured text analysis, detecting sentiment, emotions, key phrases, and word frequency through lexicon-based tools. The results are deterministic and verifiable. Code Reviewer analyses code for style issues, complexity problems, potential bugs, and improvement opportunities. This demonstrates how tool calling can extend AI capabilities into domain-specific analysis. Multi-Agent Debate showcases sequential orchestration with interdependent outputs. Three agents—one arguing for a position, one against, and a moderator—debate a topic. Each agent receives the previous agent's output, demonstrating how multi-agent systems can explore topics from multiple perspectives. Troubleshooting Common issues and their solutions: foundry: command not found : Install Foundry Local from github.com/microsoft/Foundry-Local foundry-local-sdk is not installed : Run pip install foundry-local-sdk Model download is slow: First download can be large. It's cached for future runs. No documents found warning: Add .txt or .md files to the --docs folder Agent output is low quality: Try a larger model alias, e.g. --model phi-3.5-mini Web UI won't start: Ensure Flask is installed: pip install flask Port 5000 in use: The web UI uses port 5000. Stop other services or set PORT=8080 environment variable Key Takeaways Multi-agent systems decompose complex tasks: Specialised agents (Planner, Retriever, Critic, Writer) produce better results than single-agent approaches by focusing each agent on what it does best Local AI eliminates cloud dependencies: Foundry Local provides on-device inference with automatic hardware acceleration, keeping all data on your machine MAF simplifies agent development: The ChatAgent abstraction handles message threading, tool execution, and response parsing, letting you focus on agent behaviour Three orchestration patterns serve different needs: Sequential pipelines maintain dependencies; concurrent fan-out parallelises independent work; feedback loops enable iterative quality improvement Feedback loops improve quality: The Critic–Retriever feedback loop catches gaps and contradictions, iterating until quality standards are met rather than producing incomplete results Tool calling adds precision: Deterministic functions for counting, calculation, and analysis complement LLM reasoning for more reliable results The same patterns scale to production: This demo architecture—bootstrapping, agent creation, orchestration—applies directly to real-world research and analysis systems Conclusion and Next Steps The Local Research & Synthesis Desk demonstrates that sophisticated multi-agent AI systems don't require cloud infrastructure. With Microsoft Agent Framework for orchestration and Foundry Local for inference, you can build production-quality workflows that run entirely on your hardware. The architecture patterns shown here—specialised agents with clear roles, sequential pipelines for dependent tasks, concurrent fan-out for independent work, feedback loops for quality assurance, and tool calling for precision—form a foundation for building more sophisticated systems. Consider extending this demo with: Additional agents for fact-checking, summarisation, or domain-specific analysis Richer tool integrations connecting to databases, APIs, or local services Human-in-the-loop approval gates before producing final reports Different model sizes for different agents based on task complexity Start with the demo, understand the patterns, then apply them to your own research and analysis challenges. The future of AI isn't just cloud models—it's intelligent systems that run wherever your data lives. Resources Local Research & Synthesis Desk Repository – Full source code with documentation and examples Foundry Local – Official site for on-device AI inference Foundry Local GitHub Repository – Installation instructions and CLI reference Foundry Local SDK Documentation – Python SDK reference on Microsoft Learn Microsoft Agent Framework Documentation – Official MAF tutorials and user guides MAF Orchestrations Overview – Deep dive into workflow patterns agent-framework-core on PyPI – Python package for MAF Agent Framework Samples – Additional MAF examples and patternsDeploying Custom Models with Microsoft Olive and Foundry Local
Over the past few weeks, we've been on quite a journey together. We started by exploring what makes Phi-4 and small language models so compelling, then got our hands dirty running models locally with Foundry Local. We leveled up with function calling, and most recently built a complete multi-agent quiz application with an orchestrator coordinating specialist agents. Our quiz app works great locally, but it relies on Foundry Local's catalog models — pre-optimized and ready to go. What happens when you want to deploy a model that isn't in the catalog? Maybe you've fine-tuned a model on domain-specific quiz data, or a new model just dropped on Hugging Face that you want to use. Today we'll take a model from Hugging Face, optimize it with Microsoft Olive, register it with Foundry Local, and run our quiz app against it. The same workflow applies to any model you might fine-tune for your specific use case. Understanding Deployment Options Before we dive in, let's understand the landscape of deployment options for SLM applications. There are several routes to deploying SLM applications depending on your target environment. The Three Main Paths vLLM is the industry standard for cloud deployments — containerized, scalable, handles many concurrent users. Great for Azure VMs or Kubernetes. Ollama offers a middle ground — simpler than vLLM but still provides Docker support for easy sharing and deployment. Foundry Local + Olive is Microsoft's edge-first approach. Optimize your model with Olive, serve with Foundry Local or a custom server. Perfect for on-premise, offline, or privacy-focused deployments. In keeping with the edge-first theme that's run through this series, we'll focus on the Foundry Local path. We'll use Qwen 2.5-0.5B-Instruct — small enough to optimize quickly and demonstrate the full workflow. Think of it as a stand-in for a model you've fine-tuned on your own quiz data. Prerequisites You'll need: Foundry Local version 0.8.117 or later Python 3.10+ for the quiz app (the foundry-local-sdk requires it) A separate Python 3.9 environment for Olive (Olive 0.9.x has this requirement) The quiz app from the previous article Having two Python versions might seem odd, but it mirrors a common real-world setup: you optimize models in one environment and serve them in another. The optimization is a one-time step. Installing Olive Dependencies In your Python 3.9 environment: pip install olive-ai onnxruntime onnxruntime-genai pip install transformers>=4.45.0,<5.0.0 Important: Olive is not compatible with Transformers 5.x. You must use version 4.x. Model Optimization with Olive Microsoft Olive is the bridge between a Hugging Face model and something Foundry Local can serve. It handles ONNX conversion, graph optimization, and quantization in a single command. Understanding Quantization Quantization reduces model size by converting weights from high-precision floating point to lower-precision integers: Precision Size Reduction Quality Best For FP32 Baseline Best Development, debugging FP16 50% smaller Excellent GPU inference with plenty of VRAM INT8 75% smaller Very Good Balanced production INT4 87.5% smaller Good Edge devices, resource-constrained We'll use INT4 to demonstrate the maximum compression. For production with better quality, consider INT8 — simply change --precision int4 to --precision int8 in the commands below. Running the Optimization The optimization script at scripts/optimize_model.py handles two things: downloading the model locally (to avoid authentication issues), then running Olive. The download step is important. The ONNX Runtime GenAI model builder internally requests HuggingFace authentication even for public models. Rather than configuring tokens, we download the model first with token=False, then point Olive at the local path: from huggingface_hub import snapshot_download local_path = snapshot_download("Qwen/Qwen2.5-0.5B-Instruct", token=False) Then the Olive command runs against the local copy: cmd = [ sys.executable, "-m", "olive", "auto-opt", "--model_name_or_path", local_path, "--trust_remote_code", "--output_path", "models/qwen2.5-0.5b-int4", "--device", "cpu", "--provider", "CPUExecutionProvider", "--precision", "int4", "--use_model_builder", "--use_ort_genai", "--log_level", "1", ] Key flags: --precision int4 quantizes weights to 4-bit integers, --use_model_builder reads each transformer layer and exports it to ONNX, and --use_ort_genai outputs in the format Foundry Local consumes. Run it: python scripts/optimize_model.py This process takes about a minute. When complete, you'll see the output directory structure. models/qwen2.5-0.5b-int4/model/ ├── model.onnx # ONNX graph (162 KB) ├── model.onnx.data # Quantized INT4 weights (823 MB) ├── genai_config.json # ONNX Runtime GenAI config ├── tokenizer.json # Tokenizer vocabulary (11 MB) ├── vocab.json # Token-to-ID map (2.7 MB) ├── merges.txt # BPE merges (1.6 MB) ├── tokenizer_config.json ├── config.json ├── generation_config.json ├── special_tokens_map.json └── added_tokens.json Total size: approximately 838MB — a significant reduction from the original, while maintaining usable quality for structured tasks like quiz generation. Registering with Foundry Local With the model optimized, we need to register it with Foundry Local. Unlike cloud model registries, there's no CLI command — you place files in the right directory and Foundry discovers them automatically. Foundry's Model Registry foundry cache cd # Windows: C:\Users\<username>\.foundry\cache\ # macOS/Linux: ~/.foundry/cache/ Foundry organizes models by publisher: .foundry/cache/models/ ├── foundry.modelinfo.json ← catalog of official models ├── Microsoft/ ← pre-optimized Microsoft models │ ├── qwen2.5-7b-instruct-cuda-gpu-4/ │ ├── Phi-4-cuda-gpu-1/ │ └── ... └── Custom/ ← your models go here The Registration Script The script at scripts/register_model.sh does two things: copies all model files into the Foundry cache, and creates the inference_model.json configuration file. The critical file is inference_model.json — without it, Foundry won't recognize your model: { "Name": "qwen-quiz-int4", "PromptTemplate": { "system": "<|im_start|>system\n{Content}<|im_end|>", "user": "<|im_start|>user\n{Content}<|im_end|>", "assistant": "<|im_start|>assistant\n{Content}<|im_end|>", "prompt": "<|im_start|>user\n{Content}<|im_end|>\n<|im_start|>assistant" } } The PromptTemplate defines the ChatML format that Qwen 2.5 expects. The {Content} placeholder is where Foundry injects the actual message content at runtime. If you were deploying a Llama or Phi model, you'd use their respective prompt templates. Run the registration: scripts/register_model.sh Verify Registration foundry cache ls Test the Model foundry model run qwen-quiz-int4 The model loads via ONNX Runtime on CPU. Try a simple prompt to verify it responds. Integrating with the Quiz App Here's where things get interesting. The application-level change is one line in utils/foundry_client.py: # Before: DEFAULT_MODEL_ALIAS = "qwen2.5-7b-instruct-cuda-gpu" # After: DEFAULT_MODEL_ALIAS = "qwen-quiz-int4" But that one line raised some issues worth understanding. Issue 1: The SDK Can't See Custom Models The Foundry Local Python SDK resolves models by looking them up in the official catalog — a JSON file of Microsoft-published models. Custom models in the Custom/ directory aren't in that catalog. So FoundryLocalManager("qwen-quiz-int4") throws a "model not found" error, despite foundry cache ls and foundry model run both working perfectly. The fix in foundry_client.py is a dual code path. It tries the SDK first (works for catalog models), and when that fails with a "not found in catalog" error, it falls back to discovering the running service endpoint directly: def _discover_endpoint(): """Discover running Foundry service endpoint via CLI.""" result = subprocess.run( ["foundry", "service", "status"], capture_output=True, text=True, timeout=10 ) match = re.search(r"(http://\S+?)(?:/openai)?/status", result.stdout) if not match: raise ConnectionError( "Foundry service is not running.\n" f"Start it with: foundry model run {DEFAULT_MODEL_ALIAS}" ) return match.group(1) The workflow becomes two terminals: Terminal 1: foundry model run qwen-quiz-int4 Terminal 2: python main.py The client auto-discovers the endpoint and connects. For catalog models, the existing FoundryLocalManager path works unchanged. Issue 2: Tool Calling Format For catalog models, Foundry's server-side middleware intercepts <tool_call> tags in the model's output and converts them into structured tool_calls objects in the API response. This is configured via metadata in foundry.modelinfo.json. For custom models, those metadata fields aren't recognized — Foundry ignores them in inference_model.json. The <tool_call> tags pass through as raw text in response.choices[0].message.content. Since our custom model outputs the exact same <tool_call> format, we added a small fallback parser in agents/base_agent.py — the same pattern we explored in our function calling article. After each model response, if tool_calls is None, we scan the content for tags: def _parse_text_tool_calls(content: str) -> list: """Parse <tool_call>...</tool_call> tags from model output.""" blocks = re.findall(r"<tool_call>\s*(\{.*?\})\s*</tool_call>", content, re.DOTALL) calls = [] for block in blocks: try: data = json.loads(block) calls.append(_TextToolCall(data["name"], json.dumps(data.get("arguments", {})))) except (json.JSONDecodeError, KeyError): continue return calls The model's behavior is identical; only the parsing location changes — from server-side (Foundry middleware) to client-side (our code). Part 7: Testing the Deployment With the model running in one terminal, start the quiz app in another: Terminal 1: foundry model run qwen-quiz-int4 Terminal 2: cd multi_agents_slm && python main.py Now test the full flow. Generate a quiz: Test the Full Flow Generate a quiz: Example output: The orchestrator successfully calls the generate_new_quiz tool, and the QuizGeneratorAgent produces well-structured quiz JSON. Model Limitations The 0.5B INT4 model occasionally struggles with complex reasoning or basic arithmetic. This is expected from such a small, heavily quantized model. For production use cases requiring higher accuracy, use Qwen 2.5-1.5B or Qwen 2.5-7B for better quality, or use INT8 quantization instead of INT4. The deployment workflow remains identical — just change the model name and precision in the optimization script. What You've Accomplished Take a moment to appreciate the complete journey across this series: Article What You Learned 1. Phi-4 Introduction Why SLMs matter, performance vs size tradeoffs 2. Running Locally Foundry Local setup, basic inference 3. Function Calling Tool use, external API integration 4. Multi-Agent Systems Orchestration, specialist agents 5. Deployment Olive optimization, Foundry Local registration, custom model deployment You now have end-to-end skills for building production SLM applications: understanding the landscape, local development with Foundry Local, agentic applications with function calling, multi-agent architectures, model optimization with Olive, and deploying custom models to the edge. Where to Go From Here The logical next step is fine-tuning for your domain. Medical quiz tutors trained on USMLE questions, legal assistants trained on case law, company onboarding bots trained on internal documentation — use the same Olive workflow to optimize and deploy your fine-tuned model. The same ONNX model we registered with Foundry Local could also run on mobile devices via ONNX Runtime Mobile, or be containerized for server-side edge deployment. The full source code, including the optimization and registration scripts, is available in the GitHub repository. Resources: Microsoft Olive — Model optimization toolkit Foundry Local Documentation — Setup and CLI reference Compiling Hugging Face models for Foundry Local — Official guide ONNX Runtime GenAI — Powers Foundry Local's inference Edge AI for Beginners — Microsoft's 8-module Edge AI curriculum Quiz App Source Code — Full repository with deployment scripts This series has been a joy to write. I'd love to see what you build — share your projects in the comments, and don't hesitate to open issues on the GitHub repo if you encounter challenges. Until next time — keep building, keep optimizing, and keep pushing what's possible with local AI.Advanced Function Calling and Multi-Agent Systems with Small Language Models in Foundry Local
Advanced Function Calling and Multi-Agent Systems with Small Language Models in Foundry Local In our previous exploration of function calling with Small Language Models, we demonstrated how to enable local SLMs to interact with external tools using a text-parsing approach with regex patterns. While that method worked, it required manual extraction of function calls from the model's output; functional but fragile. Today, I'm excited to show you something far more powerful: Foundry Local now supports native OpenAI-compatible function calling with select models. This update transforms how we build agentic AI systems locally, making it remarkably straightforward to create sophisticated multi-agent architectures that rival cloud-based solutions. What once required careful prompt engineering and brittle parsing now works seamlessly through standardized API calls. We'll build a complete multi-agent quiz application that demonstrates both the elegance of modern function calling and the power of coordinated agent systems. The full source code is available in this GitHub repository, but rather than walking through every line of code, we'll focus on how the pieces work together and what you'll see when you run it. What's New: Native Function Calling in Foundry Local As we explored in our guide to running Phi-4 locally with Foundry Local, we ran powerful language models on our local machine. The latest version now support native function calling for models specifically trained with this capability. The key difference is architectural. In our weather assistant example, we manually parsed JSON strings from the model's text output using regex patterns and frankly speaking, meticulously testing and tweaking the system prompt for the umpteenth time 🙄. Now, when you provide tool definitions to supported models, they return structured tool_calls objects that you can directly execute. Currently, this native function calling capability is available for the Qwen 2.5 family of models in Foundry Local. For this tutorial, we're using the 7B variant, which strikes a great balance between capability and resource requirements. Quick Setup Getting started requires just a few steps. First, ensure you have Foundry Local installed. On Windows, use winget install Microsoft.FoundryLocal , and on macOS, use bash brew install microsoft/foundrylocal/foundrylocal You'll need version 0.8.117 or later. Install the Python dependencies in the requirements file, then start your model. The first run will download approximately 4GB: foundry model run qwen2.5-7b-instruct-cuda-gpu If you don't have a compatible GPU, use the CPU version instead, or you can specify any other Qwen 2.5 variant that suits your hardware. I have set a DEFAULT_MODEL_ALIAS variable you can modify to use different models in utils/foundry_client.py file. Keep this terminal window open. The model needs to stay running while you develop and test your application. Understanding the Architecture Before we dive into running the application, let's understand what we're building. Our quiz system follows a multi-agent architecture where specialized agents handle distinct responsibilities, coordinated by a central orchestrator. The flow works like this: when you ask the system to generate a quiz about photosynthesis, the orchestrator agent receives your message, understands your intent, and decides which tool to invoke. It doesn't try to generate the quiz itself, instead, it calls a tool that creates a specialist QuizGeneratorAgent focused solely on producing well-structured quiz questions. Then there's another agent, reviewAgent, that reviews the quiz with you. The project structure reflects this architecture: quiz_app/ ├── agents/ # Base agent + specialist agents ├── tools/ # Tool functions the orchestrator can call ├── utils/ # Foundry client connection ├── data/ ├── quizzes/ # Generated quiz JSON files │── responses/ # User response JSON files └── main.py # Application entry point The orchestrator coordinates three main tools: generate_new_quiz, launch_quiz_interface, and review_quiz_interface. Each tool either creates a specialist agent or launches an interactive interface (Gradio), handling the complexity so the orchestrator can focus on routing and coordination. How Native Function Calling Works When you initialize the orchestrator agent in main.py, you provide two things: tool schemas that describe your functions to the model, and a mapping of function names to actual Python functions. The schemas follow the OpenAI function calling specification, describing each tool's purpose, parameters, and when it should be used. Here's what happens when you send a message to the orchestrator: The agent calls the model with your message and the tool schemas. If the model determines a tool is needed, it returns a structured tool_calls attribute containing the function name and arguments as a proper object—not as text to be parsed. Your code executes the tool, creates a message with "role": "tool" containing the result, and sends everything back to the model. The model can then either call another tool or provide its final response. The critical insight is that the model itself controls this flow through a while loop in the base agent. Each iteration represents the model examining the current state, deciding whether it needs more information, and either proceeding with another tool call or providing its final answer. You're not manually orchestrating when tools get called; the model makes those decisions based on the conversation context. Seeing It In Action Let's walk through a complete session to see how these pieces work together. When you run python main.py, you'll see the application connect to Foundry Local and display a welcome banner: Now type a request like "Generate a 5 question quiz about photosynthesis." Watch what happens in your console: The orchestrator recognized your intent, selected the generate_new_quiz tool, and extracted the topic and number of questions from your natural language request. Behind the scenes, this tool instantiated a QuizGeneratorAgent with a focused system prompt designed specifically for creating quiz JSON. The agent used a low temperature setting to ensure consistent formatting and generated questions that were saved to the data/quizzes folder. This demonstrates the first layer of the multi-agent architecture: the orchestrator doesn't generate quizzes itself. It recognizes that this task requires specialized knowledge about quiz structure and delegates to an agent built specifically for that purpose. Now request to take the quiz by typing "Take the quiz." The orchestrator calls a different tool and Gradio server is launched. Click the link to open in a browser window displaying your quiz questions. This tool demonstrates how function calling can trigger complex interactions—it reads the quiz JSON, dynamically builds a user interface with radio buttons for each question, and handles the submission flow. After you answer the questions and click submit, the interface saves your responses to the data/responses folder and closes the Gradio server. The orchestrator reports completion: The system now has two JSON files: one containing the quiz questions with correct answers, and another containing your responses. This separation of concerns is important—the quiz generation phase doesn't need to know about response collection, and the response collection doesn't need to know how quizzes are created. Each component has a single, well-defined responsibility. Now request a review. The orchestrator calls the third tool: A new chat interface opens, and here's where the multi-agent architecture really shines. The ReviewAgent is instantiated with full context about both the quiz questions and your answers. Its system prompt includes a formatted view of each question, the correct answer, your answer, and whether you got it right. This means when the interface opens, you immediately see personalized feedback: The Multi-Agent Pattern Multi-agent architectures solve complex problems by coordinating specialized agents rather than building monolithic systems. This pattern is particularly powerful for local SLMs. A coordinator agent routes tasks to specialists, each optimized for narrow domains with focused system prompts and specific temperature settings. You can use a 1.7B model for structured data generation, a 7B model for conversations, and a 4B model for reasoning, all orchestrated by a lightweight coordinator. This is more efficient than requiring one massive model for everything. Foundry Local's native function calling makes this straightforward. The coordinator reliably invokes tools that instantiate specialists, with structured responses flowing back through proper tool messages. The model manages the coordination loop—deciding when it needs another specialist, when it has enough information, and when to provide a final answer. In our quiz application, the orchestrator routes user requests but never tries to be an expert in quiz generation, interface design, or tutoring. The QuizGeneratorAgent focuses solely on creating well-structured quiz JSON using constrained prompts and low temperature. The ReviewAgent handles open-ended educational dialogue with embedded quiz context and higher temperature for natural conversation. The tools abstract away file management, interface launching, and agent instantiation, the orchestrator just knows "this tool launches quizzes" without needing implementation details. This pattern scales effortlessly. If you wanted to add a new capability like study guides or flashcards, you could just easily create a new tool or specialists. The orchestrator gains these capabilities automatically by having the tool schemas you have defined without modifying core logic. This same pattern powers production systems with dozens of specialists handling retrieval, reasoning, execution, and monitoring, each excelling in its domain while the coordinator ensures seamless collaboration. Why This Matters The transition from text-parsing to native function calling enables a fundamentally different approach to building AI applications. With text parsing, you're constantly fighting against the unpredictability of natural language output. A model might decide to explain why it's calling a function before outputting the JSON, or it might format the JSON slightly differently than your regex expects, or it might wrap it in markdown code fences. Native function calling eliminates this entire class of problems. The model is trained to output tool calls as structured data, separate from its conversational responses. The multi-agent aspect builds on this foundation. Because function calling is reliable, you can confidently delegate to specialist agents knowing they'll integrate smoothly with the orchestrator. You can chain tool calls—the orchestrator might generate a quiz, then immediately launch the interface to take it, based on a single user request like "Create and give me a quiz about machine learning." The model handles this orchestration intelligently because the tool results flow back as structured data it can reason about. Running everything locally through Foundry Local adds another dimension of value and I am genuinely excited about this (hopefully, the phi models get this functionality soon). You can experiment freely, iterate quickly, and deploy solutions that run entirely on your infrastructure. For educational applications like our quiz system, this means students can interact with the AI tutor as much as they need without cost concerns. Getting Started With Your Own Multi-Agent System The complete code for this quiz application is available in the GitHub repository, and I encourage you to clone it and experiment. Try modifying the tool schemas to see how the orchestrator's behavior changes. Add a new specialist agent for a different task. Adjust the system prompts to see how agent personalities and capabilities shift. Think about the problems you're trying to solve. Could they benefit from having different specialists handling different aspects? A customer service system might have agents for order lookup, refund processing, and product recommendations. A research assistant might have agents for web search, document summarization, and citation formatting. A coding assistant might have agents for code generation, testing, and documentation. Start small, perhaps with two or three specialist agents for a specific domain. Watch how the orchestrator learns to route between them based on the tool descriptions you provide. You'll quickly see opportunities to add more specialists, refine the existing ones, and build increasingly sophisticated systems that leverage the unique strengths of each agent while presenting a unified, intelligent interface to your users. In the next entry, we will be deploying our quizz app which will mark the end of our journey in Foundry and SLMs these past few weeks. I hope you are as excited as I am! Thanks for reading.Function Calling with Small Language Models
In our previous article on running Phi-4 locally, we built a web-enhanced assistant that could search the internet and provide informed answers. Here's what that implementation looked like: def web_enhanced_query(question): # 1. ALWAYS search (hardcoded decision) search_results = search_web(question) # 2. Inject results into prompt prompt = f"""Here are recent search results: {search_results} Question: {question} Using only the information above, give a clear answer.""" # 3. Model just summarizes what it reads return ask_phi4(endpoint, model_id, prompt) Today, we're upgrading to true function calling. With this, we have ability to transform small language models from passive text generators into intelligent agents that can: Decide when to use external tools Reason which tool bests fit each task Execute real-world actions thrugh apis Function calling represents a significant evolution in AI capabilities. Let's understand where this positions our small language models: Agent Classification Framework Simple Reflex Agents (Basic) React to immediate input with predefined rules Example: Thermostat, basic chatbot Without function calling, models operate here Model-Based Agents (Intermediate) Maintain internal state and context Example: Robot vacuum with room mapping Function calling enables this level Goal-Based Agents (Advanced) Plan multi-step sequences to achieve objectives Example: Route planner, task scheduler Function calling + reasoning enables this Learning Agents (Expert) Adapt and improve over time Example: Recommendation systems Future: Function calling + fine-tuning As usual with these articles, let's get ready to get our hands dirty! Project Setup Let's set up our environment for building function-calling assistants. Prerequisites First, ensure you have Foundry Local installed and a model running. We'll use Qwen 2.5-7B for this tutorial as it has excellent function calling support. Important: Not all small language models support function calling equally. Qwen 2.5 was specifically trained for this capability and provides a reliable experience through Foundry Local. # 1. Check Foundry Local is installed foundry --version # 2. Start the Foundry Local service foundry service start # 3. Download and run Qwen 2.5-7B foundry model run qwen2.5-7b Python Environment Setup # 1. Create Python virtual environment python -m venv venv source venv/bin/activate # Windows: venv\Scripts\activate # 2. Install dependencies pip install openai requests python-dotenv # 3. Get a free OpenWeatherMap API key # Sign up at: https://openweathermap.org/api ``` Create `.env` file: ``` OPENWEATHER_API_KEY=your_api_key_here ``` Building a Weather-Aware Assistant So in this scenario, a user wants to plan outdoor activities but needs weather context. Without function calling, You will get something like this: User: "Should I schedule my team lunch outside at 2pm in Birmingham?" Model: "That depends on weather conditions. Please check the forecast for rain and temperature." However, with fucntion-calling you get an answer that is able to look up the weather and reply with the needed context. We will do that now. Understanding Foundry Local's Function Calling Implementation Before we start coding, there's an important implementation detail to understand. Foundry Local uses a non-standard function calling format. Instead of returning function calls in the standard OpenAI tool_calls field, Qwen models return the function call as JSON text in the response content. For example, when you ask about weather, instead of: # Standard OpenAI format message.tool_calls = [ {"name": "get_weather", "arguments": {"location": "Birmingham"}} ] You get: # Foundry Local format message.content = '{"name": "get_weather", "arguments": {"location": "Birmingham"}}' This means we need to parse the JSON from the content ourselves. Don't worry—this is straightforward, and I'll show you exactly how to handle it! Step 1: Define the Weather Tool Create weather_assistant.py: import os from openai import OpenAI import requests import json import re from dotenv import load_dotenv load_dotenv() # Initialize Foundry Local client client = OpenAI( base_url="http://127.0.0.1:59752/v1/", api_key="not-needed" ) # Define weather tool tools = [ { "type": "function", "function": { "name": "get_weather", "description": "Get current weather information for a location", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "The city or location name" }, "units": { "type": "string", "description": "Temperature units", "enum": ["celsius", "fahrenheit"], "default": "celsius" } }, "required": ["location"] } } } ] A tool is necessary because it provides the model with a structured specification of what external functions are available and how to use them. The tool definition contains the function name, description, parameters schema, and information returned. Step 2: Implement the Weather Function def get_weather(location: str, units: str = "celsius") -> dict: """Fetch weather data from OpenWeatherMap API""" api_key = os.getenv("OPENWEATHER_API_KEY") url = "http://api.openweathermap.org/data/2.5/weather" params = { "q": location, "appid": api_key, "units": "metric" if units == "celsius" else "imperial" } response = requests.get(url, params=params, timeout=5) response.raise_for_status() data = response.json() temp_unit = "°C" if units == "celsius" else "°F" return { "location": data["name"], "temperature": f"{round(data['main']['temp'])}{temp_unit}", "feels_like": f"{round(data['main']['feels_like'])}{temp_unit}", "conditions": data["weather"][0]["description"], "humidity": f"{data['main']['humidity']}%", "wind_speed": f"{round(data['wind']['speed'] * 3.6)} km/h" } The model calls this function to get the weather data. it contacts OpenWeatherMap API, gets real weather data and returns it as a python dictionary Step 3: Parse Function Calls from Content This is the crucial step where we handle Foundry Local's non-standard format: def parse_function_call(content: str): """Extract function call JSON from model response""" if not content: return None json_pattern = r'\{"name":\s*"get_weather",\s*"arguments":\s*\{[^}]+\}\}' match = re.search(json_pattern, content) if match: try: return json.loads(match.group()) except json.JSONDecodeError: pass try: parsed = json.loads(content.strip()) if isinstance(parsed, dict) and "name" in parsed: return parsed except json.JSONDecodeError: pass return None Step 4: Main Chat Function with Function Calling and lastly, calling the model. Notice the tools and tool_choice parameter. Tools tells the model it is allowed to output a tool_call requesting that the function be executed. While tool_choice instructs the model how to decide whether to call a tool. def chat(user_message: str) -> str: """Process user message with function calling support""" messages = [ {"role": "user", "content": user_message} ] response = client.chat.completions.create( model="qwen2.5-7b-instruct-generic-cpu:4", messages=messages, tools=tools, tool_choice="auto", temperature=0.3, max_tokens=500 ) message = response.choices[0].message if message.content: function_call = parse_function_call(message.content) if function_call and function_call.get("name") == "get_weather": print(f"\n[Function Call] {function_call.get('name')}({function_call.get('arguments')})") args = function_call.get("arguments", {}) weather_data = get_weather(**args) print(f"[Result] {weather_data}\n") final_prompt = f"""User asked: "{user_message}" Weather data: {json.dumps(weather_data, indent=2)} Provide a natural response based on this weather information.""" final_response = client.chat.completions.create( model="qwen2.5-7b-instruct-generic-cpu:4", messages=[{"role": "user", "content": final_prompt}], max_tokens=200, temperature=0.7 ) return final_response.choices[0].message.content return message.content Step 5: Run the script Now put all the above together and run the script def main(): """Interactive weather assistant""" print("\nWeather Assistant") print("=" * 50) print("Ask about weather or general questions.") print("Type 'exit' to quit\n") while True: user_input = input("You: ").strip() if user_input.lower() in ['exit', 'quit']: print("\nGoodbye!") break if user_input: response = chat(user_input) print(f"Assistant: {response}\n") if __name__ == "__main__": if not os.getenv("OPENWEATHER_API_KEY"): print("Error: OPENWEATHER_API_KEY not set") print("Set it with: export OPENWEATHER_API_KEY='your_key_here'") exit(1) main() Note: Make sure Qwen 2.5 is running in Foundry Local in a new terminal Now let's talk about Model Context Protocol! Our weather assistant works beautifully with a single function, but what happens when you need dozens of tools? Database queries, file operations, calendar integration, email—each would require similar setup code. This is where Model Context Protocol (MCP) comes in. MCP is an open standard that provides pre-built, standardized servers for common tools. Instead of writing custom integration code for every capability, you can connect to MCP servers that handle the complexity for you. With MCP, You only need one command to enable weather, database, and file access npx @modelcontextprotocol/server-weather npx @modelcontextprotocol/server-sqlite npx @modelcontextprotocol/server-filesystem Your model automatically discovers and uses these tools without custom integration code. Learn more: Model Context Protocol Documentation EdgeAI Course - Module 03: MCP Integration Key Takeaways Function calling transforms models into agents - From passive text generators to active problem-solvers Qwen 2.5 has excellent function calling support - Specifically trained for reliable tool use Foundry Local uses non-standard format - Parse JSON from content instead of tool_calls field Start simple, then scale with MCP - Build one tool to understand the pattern, then leverage standards Documentation Running Phi-4 Locally with Foundry Local Phi-4: Small Language Models That Pack a Punch Microsoft Foundry Local GitHub EdgeAI for Beginners Course OpenWeatherMap API Documentation Model Context Protocol Qwen 2.5 Documentation Thank you for reading! I hope this article helps you build more capable AI agents with small language models. Function calling opens up incredible possibilities—from simple weather assistants to complex multi-tool workflows. 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