Mind the Specs: Grading formal specifications and KPIs as artefacts for LLM-driven code generation
Large language models now write code straight from a prompt, but the specification in between is never checked, and a model asked to judge its own work brings the same blind spots to the review. We built a pipeline that lifts a plain-language requirements bundle into two graded specifications (a formal Alloy model and a set of numerical KPI targets), scores both before a single line of code is written, and hands the graded result to the code generator. It starts from GitHub Spec Kit and the Azure Well-Architected Framework. Here is what we built, and what we learned from running it at scale. The problem Writing software used to be four separate activities: gathering requirements, writing a specification, verifying it, and implementing it. A language model collapses all four into a single step. Two of those activities used to give us a quality signal before any code existed: a formal specification you could inspect, and measurable targets an implementation had to hit. The prompt-to-code loop inherits neither. There is no externally observable signal, before a line of code is written, that the requirements a model received are even well-formed enough to drive a correct implementation. You might think the model could just check its own work. It cannot do so reliably. Ask a language model to check the logic it just wrote: not only will it bring the same blind spot to the review, but its stochastic nature will make it produce different answers on each run. A SAT solver does not behave this way. Its verdict is deterministic: the same specification produces the same verdict every time. The thing that historically kept formal specification out of everyday development was never its rigour, it was the cost of writing the specification by hand. And that is exactly the step a language model can now do. What we built We built an agentic pipeline that sits between the requirements and the generated code. In plain terms it takes the requirements once, turns them into two things that can be checked by a machine: a precise description of rules that the system must obey, and a set of measurable targets that the system must hit. These artefacts are both graded, and are handed to the code generator. We split the work in two and gave each half to the tool that is good at it. The language model does the creative part, turning messy prose into formal structure. Deterministic checks, not the model's own opinion, grade what it produces. From a single Spec Kit artefacts bundle the pipeline builds two graded specifications before any code exists, and then carries both into code generation. Since these grades are computed deterministically rather than just generated, you can actually trust them. The input is a GitHub Spec Kit bundle. Spec Kit is an open-source, specification-first toolkit: instead of prompting for code directly, you describe what you want to build, and it produces a set of structured artefacts, a feature specification, a data model, and a set of API contracts. Our pipeline reads that bundle and turns it into the two graded specifications in parallel. overview. Spec Kit artefacts on the left. The Alloy lifter (with SAT solver and the attack step) and the KPI agent run in parallel. Their graded outputs are merged into a verification report that feeds the guided code generator. A dashed baseline path feeds the goal alone to the generator for comparison. Lift the requirements into a formal model The first half is structural. An Alloy lifter translates the requirements into a formal model written in Alloy, a specification language whose rules a SAT solver can check exhaustively, and whose verdict is deterministic, so the grade never depends on asking an LLM what it thinks. A banking requirement like "zero balance discrepancies" becomes a precise, checkable rule: the money leaving one account and the money arriving in another must always add up to the balances you started with, so a transfer can never quietly create or destroy money. The solver searches for any scenario that would break the rule. We modified Spec Kit's templates to force the model to output functional requirements and their corresponding Alloy code blocks in a structured format. Against the stock templates, that change alone nearly doubled the Alloy code compilation rate, jumping from 40 to 74 percent. A machine-written specification cannot be trusted, though, so the lifter does more than write it: it attacks it. Each load-bearing rule is deliberately broken by clearing its body and injecting a clause that forces a violation and the solver is re-run on the broken model. If the solver fails after this mutation, the original rule genuinely caught the violation it was meant to catch. If it still passes, the rule never really constrained anything on its own. Mutation testing usually grades a test suite against a specification that is assumed correct; here the roles are reversed, and the specification itself is on trial. Turn the requirements into measurable targets The second half is measurable. A KPI agent takes the same Spec Kit bundle, retrieves the most relevant principles from the Azure Well-Architected Framework, and derives numerical targets in the Goal-Question-Metric style. Each target carries an explicit threshold, a direction, and a measurement method, the kind of target a monitoring tool could actually track. Where earlier automated approaches stopped at describing quality in words, this half emits the actual numbers an implementation has to satisfy. And the knowledge base is a setting, not a fixture: swapping the Well-Architected Framework for ISO 25010, the NIST Cybersecurity Framework, or Google's SRE workbook requires zero changes to the underlying code. Review the report before any code Both graded halves merge into one human-readable verification report: the patterns the model applied, which rules passed, the counterexamples the solver found, the attack results, and the KPI threshold table. A developer reads it first and can see exactly where the specification is weak: a rule that passed for the wrong reason, or a requirement that nothing covers. After revising the specification, they re-run the lifting phase. Because the process is cached, re-runs are cheap, allowing the developer to loop until the report looks perfect, all before any code exists. The work shifts from reviewing generated code after the fact to curating a specification and reading a report before anything is built. Carry the graded context into code generation Only then does the report do its real job. In the guided pipeline, the merged report becomes the context handed to a code generator, which is asked to implement each rule, requirement, and KPI threshold and to leave markers tracing the code back to them. A baseline generator gets only the plain-language goal. Same generator, same settings; the only difference is whether it can see the graded specification. Feeding graded artefacts, rather than raw prose, into code generation is the piece that ties the whole pipeline together. So three choices separate this from simply asking a model for a spec: the specification is attacked rather than trusted, the targets are numbers rather than prose, and what reaches the code generator is graded evidence rather than raw text. How we tested it We ran the pipeline at scale: 270 Alloy lifts and 1,930 KPI records, across three application domains chosen to differ sharply (banking, software-as-a-service, and healthcare), three levels of requirement detail, four knowledge bases, and three model tiers, with ten runs of each combination so a real effect could be told apart from noise. For the code-generation half, we generated two codes for each case, once with the graded report as context and once from the plain-language goal alone, and compared the two. What we found First, the foundation: the specifications proved gradeable. The rubric cleanly separated sound specifications from degenerate ones. Because it returned the same verdict run after run, the grades are reliable enough to act on. The three key observations are as follows: The model matters more than the prompt Of the two knobs a practitioner controls, the model you choose and the amount of detail you write, the model dominated by roughly nine to one. A weak model could not be rescued by richer requirements. But you do not need the most expensive one: a mid-tier model delivered about 98 percent of the best model's quality at under a third of the cost and about half the time. The cheapest tier was a false economy, producing a model the analyser could even load only 23 percent of the time. More detail can backfire More requirements are not always better. Sparse and standard requirements scored the same, but over-specified requirements collapsed: KPI quality fell from about 0.89 to about 0.73, and the effect held across all four knowledge bases. Pile in too much numerical detail and the pipeline starts echoing the numbers it was handed instead of deriving sound ones, which is the opposite of what more detail is supposed to buy. Graded context produces far better code This is the payoff, and it is the point of the whole pipeline. Across all nine combinations of domain and detail, code generated with the graded verification context scored about 8 out of 10, against about 1 out of 10 for the same generator given only the plain-language goal. The guided code carried the traceability back to each requirement, the named rules, and the structural patterns that a bare prompt gives us no way to know about. This part of the study is a single run per combination, so we report the size and the consistency of the gap rather than a precise average, but the gap was large and it held in every case. What this means for you Four things to take from our study into your own work: Write requirements at a standard, middle level of detail. Not sparse, and not exhaustively numerical. The middle is the sweet spot on both halves of the specification. Reach for a capable mid-tier model before you invest in heavy prompt engineering. Model choice moves quality more than requirement detail does, and the mid tier is the value leader. Give the code generator externally graded context instead of letting it specify for itself. That is where most of the quality gain came from. Treat the knowledge base as a setting worth tuning, not a fixed ingredient. Each is a recommendation that data supports under the conditions we tested, not a universal law. The limit Every grade measures structure, not meaning. A high score says the specification is well-formed, discriminating, and stable. It does not say whether the invariants are the right ones, or the thresholds are the right ones for your deployment. A specification can be perfectly well-formed and still describe the wrong system. That judgement stays with a human, which is where we think it belongs. The pipeline is built to make that judgement efficient by moving it earlier, to curating the specification and reading the report, rather than to remove it. Generated code should not be shipped end to end without human validation. Try it The full pipeline, every input, and the artefacts behind every figure are in the project repository. If you want the Microsoft tools it builds on, start here: Project repository: https://github.com/RadaanMadhan/Specification-Led-Development GitHub Spec Kit: https://github.com/github/spec-kit Azure Well-Architected Framework: https://learn.microsoft.com/en-us/azure/well-architected/ If you'd like to explore the work in more detail, we've included the full technical report in the project repository, covering the related work, methodology, pipeline design, experimental setup, and extended results. About the team This project was carried out by six students at Imperial College London: Leon Hausmann, Charlotte Maxwell, Radaan Madhan, Keshav Das, Anson Huang, and Ander Cobo, in collaboration with Microsoft and supervised by Lee Stott (Microsoft) and Max Cattafi (Imperial College London)Empowering the AI Generation: Microsoft's Open-Source Initiative
In a world increasingly driven by open collaboration and community-driven innovation, Microsoft has undergone a remarkable transformation. The tech giant is on a mission to provide students, startups, AI developers, and entrepreneurs with the tools and resources they need to build groundbreaking solutions. Embracing open source is at the heart of this journey.Unlock Your Future with Microsoft Student Opportunities
Ready to take your first steps toward a career in tech? As someone who transitioned from student life to a full-time job in tech, I am here to share how you can unlock incredible opportunities at Microsoft like internships, competitions, and more to kickstart your career in tech!Jupyter Notebooks in Visual Studio Code
Visual Studio Code offers many great features for Data Scientists and Python developers alike, allowing you to explore and experiment on your data using the flexibility of Jupyter Notebooks combined with the power and productivity of VS Code. Tune in to learn how to supercharge your Jupyter Notebooks with VS Code.Make Your Copilot Credits Count: A Student's Guide to Smarter AI Usage
If you're a student enrolled in GitHub Education, you already have something most developers pay for: free access to GitHub Copilot and its premium features. That's incredible. But here's the thing, free access doesn't mean unlimited usage, and not all AI interactions cost the same. Every chat message, every agent task, every model call consumes something called AI Credits, and knowing how they work will help you use Copilot smarter, produce better code, and build the kind of disciplined AI habits that professional developers are only just starting to learn. This post is inspired by a fantastic deep-dive from my collegaue developer advocate Bruno: "GitHub Copilot and Tokens: How to Keep Using AI Without Burning Your Budget" . We've taken those professional lessons and tailored them specifically for students because your learning environment, your assignments, and your goals are different from a seasoned engineer at a tech company. TL;DR: Use autocomplete before chat. Choose the right model. Keep context small. Start fresh chats often. Plan before you build. These habits will make you a better developer and stretch your credits further. What Are AI Credits and Why Do They Matter? When you interact with GitHub Copilot through chat, agent mode, or inline edits the model processes tokens. Tokens are small chunks of text (roughly 3–4 characters each). Every interaction consumes: Input tokens — everything sent to the model (your message, attached files, chat history, instructions) Output tokens — everything the model generates back to you Cached tokens — context the model reuses from previous turns (cheaper) These tokens are converted to AI Credits, where 1 AI Credit = $0.01 USD. Different models have very different token costs a lightweight model like GPT-5 mini charges $0.25 per million input tokens, while a powerful model like GPT-5.5 charges $5.00 per million input tokens (20x more expensive). Using the wrong model for a simple task is like taking a taxi to a destination that's a 5-minute walk. See the official pricing table: GitHub Copilot Models and Pricing . Figure 1: The four cost tiers of Copilot interactions. Autocomplete and Next Edit Suggestions are free — they do not consume AI Credits on paid plans Strategy 1: Tab Before Chat The Free Tier is Powerful Here is the single most impactful habit you can build: always try autocomplete before opening chat. According to GitHub's official billing documentation, code completions and Next Edit Suggestions are not billed as AI Credits on paid plans. That means every time you press Tab to accept an inline suggestion, you are getting AI assistance for free. Use autocomplete (Tab) for: Completing a line or a simple function Generating repetitive boilerplate (constructors, properties, getters/setters) Completing a repeated pattern you've started Writing obvious next lines like console.log , imports, or variable declarations Adjusting variable names inline Only move to Inline Edit (Ctrl+I / Cmd+I) when autocomplete isn't enough for a local change. Only open a Chat window when you need genuine reasoning an explanation, a plan, or a multi-step solution. As Bruno puts it: "The most expensive model in the world should not be helping you write public string Name { get; set; } . That's what Tab is for. And coffee." Strategy 2: Choose the Right Model for the Job GitHub Copilot gives you access to models from OpenAI, Anthropic, and Google each at different price points and capability levels. The key insight from VS Code's official Copilot usage guide is: reserve powerful reasoning models for tasks that genuinely need them. Your Task Recommended Model Tier Example Models Simple question or boilerplate Lightweight GPT-5 mini, Gemini 3 Flash Code explanation or basic docs Lightweight GPT-5 mini, GPT-5.4 nano Writing tests or debugging a single function Medium / Versatile Claude Haiku 4.5, GPT-5.4 Multi-file refactor or code review Medium / Versatile Claude Sonnet 4.6, GPT-5.4 Complex system design or architecture Powerful Claude Opus 4.7, GPT-5.5 Long agentic workflows Powerful (scoped!) Claude Opus 4.8, GPT-5.5 Not sure what you need Auto (recommended default) Copilot selects for you GitHub Copilot's Auto Model Selection feature automatically chooses a model based on task complexity, availability, and policies. For most students, Auto should be your default only switch manually when you have a specific reason. And when the complex task is done, switch back to Auto or a lighter model. Strategy 3: Context is Currency Smaller is Smarter Here's the counterintuitive truth that surprises most developers: the expensive part of a prompt is usually not the question you type it's everything surrounding it. Every token consumed by Copilot includes: All your previous chat messages in the session Every file you have open or attached Workspace search results Copilot pulled in Build output, terminal logs, or diff content Responses from any MCP (Model Context Protocol) servers you have enabled Your custom instructions file ( .github/copilot-instructions.md ) A single question inside a conversation with 80 messages, 12 open files, and 3 tool call results can cost significantly more than the same question asked fresh in a new chat with one relevant file attached. Figure 2: The same task asked two ways. Scope your prompts to save credits and often get better answers. Practical rules for context management: Attach only 2–3 relevant files — not your entire project Don't ask Copilot to analyse the whole repo when you only need changes in one module Paste only the first relevant error from a log, not 2,000 lines of output Remove timestamps and duplicate stack traces from pasted logs State the expected output format explicitly so the model stops early Use /compact in VS Code Chat to summarise a long conversation without losing key context Use /fork to explore an alternative direction without polluting the main conversation Strategy 4: Start Fresh Chats When You Change Tasks This is one of the simplest optimisations and one of the most ignored. The VS Code Copilot usage guide is explicit about it: when a conversation grows, it carries context from all previous messages. If you switch to an unrelated task in the same session, the model still processes that irrelevant history and you pay for it in credits. Bad pattern: Chat session: - "Help me fix the JWT bug in auth.ts" [10 messages] - "Now write unit tests for my sorting algorithm" [still in same chat!] - "Can you generate the README for my project?" [still in same chat!] - "Now debug this CSS layout issue..." [still in same chat!] Smart pattern: Chat 1: "Fix JWT bug in auth.ts" - DONE, close chat. Chat 2: "Write unit tests for sorting algorithm" - DONE, close chat. Chat 3: "Generate README for project" - fresh context, fresh cost. New task = new chat. Your human brain benefits too — focused sessions produce better outcomes than sprawling multi-topic conversations. Strategy 5: Plan Before You Build Use Agent Mode Wisely Agent mode is one of the most powerful Copilot features for students working on larger assignments — it can create files, run terminal commands, edit across multiple files, and execute tests. But agent mode also carries the highest token cost, because it loops: it plans, acts, observes tool output, then plans again. The VS Code documentation recommends separating planning from implementation to reduce rework and back-and-forth. Here's a phased approach that saves credits and produces better results: Figure 3: The credit-smart workflow. Always try the cheaper option first, escalate only when needed. Phase 1: Plan (lightweight model, low cost) I need to add user authentication to my Express app. Before writing any code, give me a step-by-step plan covering which files to create, which packages to install, and what tests to write. Do not write code yet. Phase 2: Scoped Implementation (one feature at a time) Using the plan we agreed, implement only Step 1: create src/middleware/auth.ts with JWT validation. Do not modify any other files yet. Phase 3: Validate Run the existing tests in tests/auth.test.ts and report the results. Fix only test failures related to the new auth middleware. Phase 4: Cleanup The implementation is complete. Update README.md with setup instructions for the auth module. Keep it under 200 words. Each phase is small, scoped, and verifiable. You can stop at any phase, check the result, and only continue when you're satisfied. This dramatically reduces expensive re-runs where the agent reverses its own changes. Strategy 6: Review Your MCP Servers and Custom Instructions MCP Servers MCP (Model Context Protocol) servers let Copilot connect to external tools databases, GitHub issues, Jira, Slack, browser automation, and more. Each enabled server expands what the agent can do, but also adds to the context the model must consider, which increases token usage. For students, a practical rule: only enable MCP servers relevant to your current project. If you're working on a simple Python web app, you probably don't need browser automation, a Kubernetes connector, and a Slack integration all active at the same time. See the VS Code MCP servers documentation for how to enable, disable, and configure them. Custom Instructions A .github/copilot-instructions.md file in your repository lets you give Copilot standing instructions — coding standards, testing commands, architecture conventions. This is a fantastic feature. But that file is included in every prompt's context, so a bloated instructions file costs credits on every single interaction. A good custom instructions file is: Short — under 200 words for a student project Specific to this repository's real conventions Clear about test commands (e.g., npm test , pytest ) Free of generic advice that applies to every codebase on earth Example of a good student instructions file: # Copilot Instructions for MyWebApp Language: TypeScript (strict mode) Framework: Express.js with Prisma ORM Tests: Run with `npm test` (Jest) Lint: Run with `npm run lint` (ESLint + Prettier) Conventions: - Use async/await, not callbacks - Validate all request inputs with Zod - Keep controllers thin; put logic in service files - Write a test for every new public function That's it. Short, actionable, and genuinely useful — not a 500-line manifesto. Strategy 7: Use Traditional Tools First AI is excellent for reasoning, explaining, planning, and connecting ideas. It is not the right tool for every job. Before reaching for Copilot chat, ask yourself whether a traditional tool can answer your question faster, cheaper, and more reliably: Compiler / type-checker — to find type errors (TypeScript, mypy) Linter — to find style and logic issues (ESLint, Pylint, Checkstyle) Formatter — to fix formatting (Prettier, Black, gofmt) Test runner — to confirm whether your code works (Jest, pytest, JUnit) Debugger — to step through execution and inspect state Docs / Stack Overflow — for well-documented APIs and common patterns If your linter tells you there's a missing import, fix it directly — don't ask Copilot to analyse your code to find it. Let deterministic tools do deterministic work, and let AI do the reasoning where it genuinely adds value. Your GitHub Education Benefits: What You Get If you haven't already, apply for GitHub Education with your school email address. Once verified, you receive: Free GitHub Copilot including premium features — see how to enable Copilot as a student Free GitHub Codespaces — 180 core hours per month, equivalent to GitHub Pro (great for browser-based coding with Copilot built in) GitHub Student Developer Pack — free access to dozens of professional tools from GitHub's partners, including cloud credits, domains, and IDEs GitHub Classroom — your instructors can manage assignments and provide feedback GitHub Community Exchange — discover and contribute to student-built projects Campus Experts program — become a student leader in your tech community These benefits are designed to give you real-world tools in an educational setting. Copilot is the standout feature — it's the same tool professional developers use every day. Using it wisely during your studies means you'll arrive in the workforce already ahead of the curve. Pre-Prompt Checklist for Students Before you fire off your next Copilot prompt, run through this checklist. It takes 10 seconds and can save significant credits — and more importantly, it builds the mental habits of a professional AI user. Figure 4: Two-column checklist covering what to check before opening chat and when writing your prompt. Before you open chat: ☐ Can Tab / autocomplete solve this? ☐ Is inline edit (Ctrl+I) enough for this local change? ☐ Can a linter, compiler, or test runner answer this? ☐ Is this a different task from my last message? If so, start a new chat. ☐ Am I on Auto model selection (or the right tier for this task)? ☐ Should I ask for a plan before asking for code? ☐ Do I have MCP servers enabled that I don't need right now? ☐ Is my copilot-instructions.md file concise and current? When writing your prompt: ☐ Attach only 2–3 relevant files, not the whole project ☐ Paste only the first relevant error from any logs ☐ Define the files to change, the goal, and any files not to touch ☐ Ask for a plan before implementation on complex tasks ☐ Remove timestamps and duplicate stack traces from pasted logs ☐ State the expected output format and length ☐ Use /compact if the session is getting long ☐ Use /fork to explore alternatives without polluting the main thread A Note on Responsible AI Use in Education Using Copilot smartly is not just about saving credits it's about developing genuine skills. When you ask Copilot to write all your code without understanding it, you lose the learning opportunity the assignment was designed to create. When you review and understand every suggestion Copilot makes, you learn faster, build better instincts, and can confidently explain your own work. Best practices for academic integrity with AI tools: Understand before you accept — never paste code you can't explain Use Copilot to learn, not to skip learning — ask it to explain the code it generates Follow your institution's AI policy — many universities have specific guidance on AI use in assessments Treat Copilot as a senior pair-programmer, not an answer machine — question its suggestions, push back, iterate Verify facts and documentation links — AI can hallucinate; always check official sources GitHub Education exists to give you real professional tools while you learn. The goal is for you to graduate with genuine skills, a real portfolio, and the confidence that comes from building things yourself — with AI as your collaborator, not your ghostwriter. Key Takeaways Tab first — autocomplete and Next Edit Suggestions are free; use them for everything small Auto model by default — only switch to a powerful model when you have a clear reason Context is cost — fewer files, fewer messages, fewer tools = fewer tokens New task = new chat — don't carry stale context into unrelated work Plan before you build — a 10-message plan session is cheaper than 50 messages of rework Keep instructions short — your copilot-instructions.md runs on every prompt Use traditional tools first — linters and compilers are free, fast, and deterministic Understand your code — Copilot is a collaborator, not a replacement for learning Resources and Next Steps GitHub Education — apply for your free student benefits GitHub Student Developer Pack — explore free tools for students Enable GitHub Copilot as a student GitHub Copilot: Models and Pricing — understand exactly what each model costs Auto Model Selection in GitHub Copilot VS Code: Optimising GitHub Copilot Usage — the official guide that inspired many of these tips Managing MCP Servers in VS Code El Bruno: GitHub Copilot and Tokens (the original professional perspective) GitHub Education Community Discussions — connect with students and educators worldwide This post draws on insights from El Bruno's developer blog and best practices from GitHub Education. All pricing figures are sourced from the official GitHub Copilot billing documentation and are correct as of June 2026.Build an AI-Powered Space Invaders Game
Build an AI-Powered Space Invaders Game: Integrating LLMs into HTML5 Games with Microsoft Foundry Local Introduction What if your game could talk back to you? Imagine playing Space Invaders while an AI commander taunts you during battle, delivers personalized mission briefings, and provides real-time feedback based on your performance. This isn't science fiction it's something you can build today using HTML, JavaScript, and a locally-running AI model. In this tutorial, we'll explore how to create an HTML5 game with integrated Large Language Model (LLM) features using Microsoft Foundry Local. You'll learn how to combine classic game development with modern AI capabilities, all running entirely on your own machine—no cloud services, no API costs, no internet connection required during gameplay. We'll be working with the Space Invaders - AI Commander Edition project, which demonstrates exactly how to architect games that leverage local AI. Whether you're a student learning game development, exploring AI integration patterns, or building your portfolio, this guide provides practical, hands-on experience with technologies that are reshaping how we build interactive applications. What You'll Learn By the end of this tutorial, you'll understand how to combine traditional web development with local AI inference. These skills transfer directly to building chatbots, interactive tutorials, AI-enhanced productivity tools, and any application where you want intelligent, context-aware responses. Set up Microsoft Foundry Local for running AI models on your machine Understand the architecture of games that integrate LLM features Use GitHub Copilot CLI to accelerate your development workflow Implement AI-powered game features like dynamic commentary and adaptive feedback Extend the project with your own creative AI features Why Local AI for Games? Before diving into the code, let's understand why running AI locally matters for game development. Traditional cloud-based AI services have limitations that make them impractical for real-time gaming experiences. Latency is the first challenge. Cloud API calls typically take 500ms to several seconds, an eternity in a game running at 60 frames per second. Local inference can respond in tens of milliseconds, enabling AI responses that feel instantaneous and natural. When an enemy ship appears, your AI commander can taunt you immediately, not three seconds later. Cost is another consideration. Cloud AI services charge per token, which adds up quickly when generating dynamic content during gameplay. Local models have zero per-use cost, once installed, they run entirely on your hardware. This frees you to experiment without worrying about API bills. Privacy and offline capability complete the picture. Local AI keeps all data on your machine, perfect for games that might handle player information. And since nothing requires internet connectivity, your game works anywhere, on planes, in areas with poor connectivity, or simply when you want to play without network access. Understanding Microsoft Foundry Local Microsoft Foundry Local is a runtime that enables you to run small language models (SLMs) directly on your computer. It's designed for developers who want to integrate AI capabilities into applications without requiring cloud infrastructure. Think of it as having a miniature AI assistant living on your laptop. Foundry Local handles the complex work of loading AI models, managing memory, and processing inference requests through a simple API. You send text prompts, and it returns AI-generated responses, all happening locally on your CPU or GPU. The models are optimized to run efficiently on consumer hardware, so you don't need a supercomputer. For our Space Invaders game, Foundry Local powers the "AI Commander" feature. During gameplay, the game sends context about what's happening, your score, accuracy, current level, enemies remaining and receives back contextual commentary, taunts, and encouragement. The result feels like playing alongside an AI companion who actually understands the game. Setting Up Your Development Environment Let's get your machine ready for AI-powered game development. We'll install Foundry Local, clone the project, and verify everything works. The entire setup takes about 10-15 minutes. Step 1: Install Microsoft Foundry Local Foundry Local installation varies by operating system. Open your terminal and run the appropriate command: # Windows (using winget) winget install Microsoft.FoundryLocal # macOS (using Homebrew) brew install microsoft/foundrylocal/foundrylocal These commands download and install the Foundry Local runtime along with a default small language model. The installation includes everything needed to run AI inference locally. Verify the installation by running: foundry --version If you see a version number, Foundry Local is ready. If you encounter errors, ensure you have administrator/sudo privileges and that your package manager is up to date. Step 2: Install Node.js (If Not Already Installed) Our game's AI features require a small Node.js server to communicate between the browser and Foundry Local. Check if Node.js is installed: node --version If you see a version number (v16 or higher recommended), you're set. Otherwise, install Node.js: # Windows winget install OpenJS.NodeJS.LTS # macOS brew install node # Linux sudo apt install nodejs npm Node.js provides the JavaScript runtime that powers our proxy server, bridging browser code with the local AI model. Step 3: Clone the Project Get the Space Invaders project onto your machine: git clone https://github.com/leestott/Spaceinvaders-FoundryLocal.git cd Spaceinvaders-FoundryLocal This downloads all game files, including the HTML interface, game logic, AI integration module, and server code. Step 4: Install Dependencies and Start the Server Install the Node.js packages and launch the AI-enabled server: npm install npm start The first command downloads required packages (primarily for the proxy server). The second starts the server, which listens for AI requests from the game. You should see output indicating the server is running on port 3001. Step 5: Play the Game Open your browser and navigate to: http://localhost:3001 You should see Space Invaders with "AI: ONLINE" displayed in the game HUD, indicating that AI features are active. Use arrow keys or A/D to move, SPACE to fire, and P to pause. The AI Commander will start providing commentary as you play! Understanding the Project Architecture Now that the game is running, let's explore how the different pieces fit together. Understanding this architecture will help you modify the game and apply these patterns to your own projects. The project follows a clean separation of concerns, with each file handling a specific responsibility: Spaceinvaders-FoundryLocal/ ├── index.html # Main game page and UI structure ├── styles.css # Retro arcade visual styling ├── game.js # Core game logic and rendering ├── llm.js # AI integration module ├── sound.js # Web Audio API sound effects ├── server.js # Node.js proxy for Foundry Local └── package.json # Project configuration index.html: Defines the game canvas and UI elements. It's the entry point that loads all other modules. game.js: Contains the game loop, physics, collision detection, scoring, and rendering logic. This is the heart of the game. llm.js: Handles all communication with the AI backend. It formats game state into prompts and processes AI responses. server.js: A lightweight Express server that proxies requests between the browser and Foundry Local. sound.js: Synthesizes retro sound effects using the Web Audio API—no audio files needed! How the AI Integration Works The magic of the AI Commander happens through a simple but powerful pattern. Let's trace the flow from gameplay event to AI response. When something interesting happens in the game, you clear a wave, achieve a combo, or lose a life, the game logic in game.js triggers an AI request. This request includes context about the current game state: your score, accuracy percentage, current level, lives remaining, and what just happened. The llm.js module formats this context into a prompt. For example, when you clear a wave with 85% accuracy, it might construct: You are an AI Commander in a Space Invaders game. The player just cleared wave 3 with 85% accuracy. Score: 12,500. Lives: 3. Provide a brief, enthusiastic comment (1-2 sentences). This prompt travels to server.js , which forwards it to Foundry Local. The AI model processes the prompt and generates a response like: "Impressive accuracy, pilot! Wave 3 didn't stand a chance. Keep that trigger finger sharp!" The response flows back through the server to the browser, where llm.js passes it to the game. The game displays the message in the HUD, creating the illusion of playing alongside an AI companion. This entire round trip typically completes in 50-200 milliseconds, fast enough to feel responsive without interrupting gameplay. Using GitHub Copilot CLI to Explore and Modify the Code GitHub Copilot CLI accelerates your development workflow by letting you ask questions and generate code directly in your terminal. Let's use it to understand and extend the Space Invaders project. Installing Copilot CLI If you haven't installed Copilot CLI yet, here's the quick setup: # Install GitHub CLI winget install GitHub.cli # Windows brew install gh # macOS # Authenticate with GitHub gh auth login # Add Copilot extension gh extension install github/gh-copilot # Verify installation gh copilot --help With Copilot CLI ready, you can interact with AI directly from your terminal while working on the project. Exploring Code with Copilot CLI Use Copilot to understand unfamiliar code. Navigate to the project directory and try: gh copilot explain "How does llm.js communicate with the server?" Copilot analyzes the code and explains the communication pattern, helping you understand the architecture without reading every line manually. You can also ask about specific functions: gh copilot explain "What does the generateEnemyTaunt function do?" This accelerates onboarding to unfamiliar codebases, a valuable skill when working with open source projects or joining teams. Generating New Features Want to add a new AI feature? Ask Copilot to help generate the code: gh copilot suggest "Create a function that asks the AI to generate a mission briefing at the start of each level, including the level number and a random mission objective" Copilot generates starter code that you can customize and integrate. This combination of AI-powered development tools and AI-integrated gameplay demonstrates how LLMs are transforming both how we build games and how games behave. Customizing the AI Commander The default AI Commander provides generic gaming commentary, but you can customize its personality and responses. Open llm.js to find the prompt templates that control AI behavior. Changing the AI's Personality The system prompt defines who the AI "is." Find the base prompt and modify it: // Original const systemPrompt = "You are an AI Commander in a Space Invaders game."; // Customized - Drill Sergeant personality const systemPrompt = `You are Sergeant Blaster, a gruff but encouraging drill sergeant commanding space cadets. Use military terminology, call the player "cadet," and be tough but fair.`; // Customized - Supportive Coach personality const systemPrompt = `You are Coach Nova, a supportive and enthusiastic gaming coach. Use encouraging language, celebrate small victories, and provide gentle guidance when players struggle.`; These personality changes dramatically alter the game's feel without changing any gameplay code. It's a powerful example of how AI can add variety to games with minimal development effort. Adding New Commentary Triggers Currently the AI responds to wave completions and game events. You can add new triggers in game.js : // Add AI commentary when player achieves a kill streak if (killStreak >= 5 && !streakCommentPending) { requestAIComment('killStreak', { count: killStreak }); streakCommentPending = true; } // Add AI reaction when player narrowly avoids death if (nearMissOccurred) { requestAIComment('nearMiss', { livesRemaining: lives }); } Each new trigger point adds another opportunity for the AI to engage with the player, making the experience more dynamic and personalized. Understanding the Game Features Beyond AI integration, the Space Invaders project demonstrates solid game development patterns worth studying. Let's explore the key features. Power-Up System The game includes eight different power-ups, each with unique effects: SPREAD (Orange): Fires three projectiles in a spread pattern LASER (Red): Powerful beam with high damage RAPID (Yellow): Dramatically increased fire rate MISSILE (Purple): Homing projectiles that track enemies SHIELD (Blue): Grants an extra life EXTRA LIFE (Green): Grants two extra lives BOMB (Red): Destroys all enemies on screen BONUS (Gold): Random score bonus between 250-750 points Power-ups demonstrate state management, tracking which power-up is active, applying its effects to player actions, and handling timeouts. Study the power-up code in game.js to understand how temporary state modifications work. Leaderboard System The game persists high scores using the browser's localStorage API: // Saving scores localStorage.setItem('spaceInvadersScores', JSON.stringify(scores)); // Loading scores const savedScores = localStorage.getItem('spaceInvadersScores'); const scores = savedScores ? JSON.parse(savedScores) : []; This pattern works for any data you want to persist between sessions—game progress, user preferences, or accumulated statistics. It's a simple but powerful technique for web games. Sound Synthesis Rather than loading audio files, the game synthesizes retro sound effects using the Web Audio API in sound.js . This approach has several benefits: no external assets to load, smaller project size, and complete control over sound parameters. Examine how oscillators and gain nodes combine to create laser sounds, explosions, and victory fanfares. This knowledge transfers directly to any web project requiring audio feedback. Extending the Project: Ideas for Students Ready to make the project your own? Here are ideas ranging from beginner-friendly to challenging, each teaching valuable skills. Beginner: Customize Visual Theme Modify styles.css to create a new visual theme. Try changing the color scheme from green to blue, or create a "sunset" theme with orange and purple gradients. This builds CSS skills while making the game feel fresh. Intermediate: Add New Enemy Types Create a new enemy class in game.js with different movement patterns. Perhaps enemies that move in sine waves, or boss enemies that take multiple hits. This teaches object-oriented programming and game physics. Intermediate: Expand AI Interactions Add new AI features like: Pre-game mission briefings that set up the story Dynamic difficulty hints when players struggle Post-game performance analysis and improvement suggestions AI-generated names for enemy waves Advanced: Multiplayer Commentary Modify the game for two-player support and have the AI provide play-by-play commentary comparing both players' performance. This combines game networking concepts with advanced AI prompting. Advanced: Voice Integration Use the Web Speech API to speak the AI Commander's responses aloud. This creates a more immersive experience and demonstrates browser speech synthesis capabilities. Troubleshooting Common Issues If something isn't working, here are solutions to common problems. "AI: OFFLINE" Displayed in Game This means the game can't connect to the AI server. Check that: The server is running ( npm start shows no errors) You're accessing the game via http://localhost:3001 , not directly opening the HTML file Foundry Local is installed correctly ( foundry --version works) Server Won't Start If npm start fails: Ensure you ran npm install first Check that port 3001 isn't already in use by another application Verify Node.js is installed ( node --version ) AI Responses Are Slow Local AI performance depends on your hardware. If responses feel sluggish: Close other resource-intensive applications Ensure your laptop is plugged in (battery mode may throttle CPU) Consider that first requests may be slower as the model loads Key Takeaways Local AI enables real-time game features: Microsoft Foundry Local provides fast, free, private AI inference perfect for gaming applications Clean architecture matters: Separating game logic, AI integration, and server code makes projects maintainable and extensible AI personality is prompt-driven: Changing a few lines of prompt text completely transforms how the AI interacts with players Copilot CLI accelerates learning: Use it to explore unfamiliar code and generate new features quickly The patterns transfer everywhere: Skills from this project apply to chatbots, assistants, educational tools, and any AI-integrated application Conclusion and Next Steps You've now seen how to integrate AI capabilities into a browser-based game using Microsoft Foundry Local. The Space Invaders project demonstrates that modern AI features don't require cloud services or complex infrastructure, they can run entirely on your laptop, responding in milliseconds. More importantly, you've learned patterns that extend far beyond gaming. The architecture of sending context to an AI, receiving generated responses, and integrating them into user experiences applies to countless applications: customer support bots, educational tutors, creative writing tools, and accessibility features. Your next step is experimentation. Clone the repository, modify the AI's personality, add new commentary triggers, or build an entirely new game using these patterns. The combination of GitHub Copilot CLI for development assistance and Foundry Local for runtime AI gives you powerful tools to bring intelligent applications to life. Start playing, start coding, and discover what you can create when your games can think. Resources Space Invaders - AI Commander Edition Repository - Full source code and documentation Play Space Invaders Online - Try the basic version without AI features Microsoft Foundry Local Documentation - Official installation and API guide GitHub Copilot CLI Documentation - Installation and usage guide GitHub Education - Free developer tools for students Web Audio API Documentation - Learn about browser sound synthesis Canvas API Documentation - Master HTML5 game rendering
