Agents League: Meet the Winners
Agents League brought together developers from around the world to build AI agents using Microsoft's developer tools. With 100+ submissions across three tracks, choosing winners was genuinely difficult. Today, we're proud to announce the category champions. 🎨 Creative Apps Winner: CodeSonify View project CodeSonify turns source code into music. As a genuinely thoughtful system, its functions become ascending melodies, loops create rhythmic patterns, conditionals trigger chord changes, and bugs produce dissonant sounds. It supports 7 programming languages and 5 musical styles, with each language mapped to its own key signature and code complexity directly driving the tempo. What makes CodeSonify stand out is the depth of execution. CodeSonify team delivered three integrated experiences: a web app with real-time visualization and one-click MIDI export, an MCP server exposing 5 tools inside GitHub Copilot in VS Code Agent Mode, and a diff sonification engine that lets you hear a code review. A clean refactor sounds harmonious. A messy one sounds chaotic. The team even built the MIDI generator from scratch in pure TypeScript with zero external dependencies. Built entirely with GitHub Copilot assistance, this is one of those projects that makes you think about code differently. 🧠Reasoning Agents Winner: CertPrep Multi-Agent System View project CertPrep Multi-Agent System team built a production-grade 8-agent system for personalized Microsoft certification exam preparation, supporting 9 exam families including AI-102, AZ-204, AZ-305, and more. Each agent has a distinct responsibility: profiling the learner, generating a week-by-week study schedule, curating learning paths, tracking readiness, running mock assessments, and issuing a GO / CONDITIONAL GO / NOT YET booking recommendation. The engineering behind the scene here is impressive. A 3-tier LLM fallback chain ensures the system runs reliably even without Azure credentials, with the full pipeline completing in under 1 second in mock mode. A 17-rule guardrail pipeline validates every agent boundary. Study time allocation uses the Largest Remainder algorithm to guarantee no domain is silently zeroed out. 342 automated tests back it all up. This is what thoughtful multi-agent architecture looks like in practice. 💼 Enterprise Agents Winner: Whatever AI Assistant (WAIA) View project WAIA is a production-ready multi-agent system for Microsoft 365 Copilot Chat and Microsoft Teams. A workflow agent routes queries to specialized HR, IT, or Fallback agents, transparently to the user, handling both RAG-pattern Q&A and action automation — including IT ticket submission via a SharePoint list. Technically, it's a showcase of what serious enterprise agent development looks like: a custom MCP server secured with OAuth Identity Passthrough, streaming responses via the OpenAI Responses API, Adaptive Cards for human-in-the-loop approval flows, a debug mode accessible directly from Teams or Copilot, and full OpenTelemetry integration visible in the Foundry portal. Franck also shipped end-to-end automated Bicep deployment so the solution can land in any Azure environment. It's polished, thoroughly documented, and built to be replicated. Thank you To every developer who submitted and shipped projects during Agents League: thank you 💜 Your creativity and innovation brought Agents League to life! 👉 Browse all submissions on GitHubBuilding a Smart Building HVAC Digital Twin with AI Copilot Using Foundry Local
Introduction Building operations teams face a constant challenge: optimizing HVAC systems for energy efficiency while maintaining occupant comfort and air quality. Traditional building management systems display raw sensor data, temperatures, pressures, CO₂ levels—but translating this into actionable insights requires deep HVAC expertise. What if operators could simply ask "Why is the third floor so warm?" and get an intelligent answer grounded in real building state? This article demonstrates building a sample smart building digital twin with an AI-powered operations copilot, implemented using DigitalTwin, React, Three.js, and Microsoft Foundry Local. You'll learn how to architect physics-based simulators that model thermal dynamics, implement 3D visualizations of building systems, integrate natural language AI control, and design fault injection systems for testing and training. Whether you're building IoT platforms for commercial real estate, designing energy management systems, or implementing predictive maintenance for building automation, this sample provides proven patterns for intelligent facility operations. Why Digital Twins Matter for Building Operations Physical buildings generate enormous operational data but lack intelligent interpretation layers. A 50,000 square foot office building might have 500+ sensors streaming metrics every minute, zone temperatures, humidity levels, equipment runtimes, energy consumption. Traditional BMS (Building Management Systems) visualize this data as charts and gauges, but operators must manually correlate patterns, diagnose issues, and predict failures. Digital twins solve this through physics-based simulation coupled with AI interpretation. Instead of just displaying current temperature readings, a digital twin models thermal dynamics, heat transfer rates, HVAC response characteristics, occupancy impacts. When conditions deviate from expectations, the twin compares observed versus predicted states, identifying root causes. Layer AI on top, and operators get natural language explanations: "The conference room is 3 degrees too warm because the VAV damper is stuck at 40% open, reducing airflow by 60%." This application focuses on HVAC, the largest building energy consumer, typically 40-50% of total usage. Optimizing HVAC by just 10% through better controls can save thousands of dollars monthly while improving occupant satisfaction. The digital twin enables "what-if" scenarios before making changes: "What happens to energy consumption and comfort if we raise the cooling setpoint by 2 degrees during peak demand response events?" Architecture: Three-Tier Digital Twin System The application implements a clean three-tier architecture separating visualization, simulation, and state management: The frontend uses React with Three.js for 3D visualization. Users see an interactive 3D model of the three-floor building with color-coded zones indicating temperature and CO₂ levels. Click any equipment, AHUs, VAVs, chillers, to see detailed telemetry. The control panel enables adjusting setpoints, running simulation steps, and activating demand response scenarios. Real-time charts display KPIs: energy consumption, comfort compliance, air quality levels. The backend Node.js/Express server orchestrates simulation and state management. It maintains the digital twin state as JSON, the single source of truth for all equipment, zones, and telemetry. REST API endpoints handle control requests, simulation steps, and AI copilot queries. WebSocket connections push real-time updates to the frontend for live monitoring. The HVAC simulator implements physics-based models: 1R1C thermal models for zones, affinity laws for fan power, chiller COP calculations, CO₂ mass balance equations. Foundry Local provides AI copilot capabilities. The backend uses foundry-local-sdk to query locally running models. Natural language queries ("How's the lobby temperature?") get answered with building state context. The copilot can explain anomalies, suggest optimizations, and even execute commands when explicitly requested. Implementing Physics-Based HVAC Simulation Accurate simulation requires modeling actual HVAC physics. The simulator implements several established building energy models: // backend/src/simulator/thermal-model.js class ZoneThermalModel { // 1R1C (one resistance, one capacitance) thermal model static calculateTemperatureChange(zone, delta_t_seconds) { const C_thermal = zone.volume * 1.2 * 1000; // Heat capacity (J/K) const R_thermal = zone.r_value * zone.envelope_area; // Thermal resistance // Internal heat gains (occupancy, equipment, lighting) const Q_internal = zone.occupancy * 100 + // 100W per person zone.equipment_load + zone.lighting_load; // Cooling/heating from HVAC const airflow_kg_s = zone.vav.airflow_cfm * 0.0004719; // CFM to kg/s const c_p_air = 1006; // Specific heat of air (J/kg·K) const Q_hvac = airflow_kg_s * c_p_air * (zone.vav.supply_temp - zone.temperature); // Envelope losses const Q_envelope = (zone.outdoor_temp - zone.temperature) / R_thermal; // Net energy balance const Q_net = Q_internal + Q_hvac + Q_envelope; // Temperature change: Q = C * dT/dt const dT = (Q_net / C_thermal) * delta_t_seconds; return zone.temperature + dT; } } This model captures essential thermal dynamics while remaining computationally fast enough for real-time simulation. It accounts for internal heat generation from occupants and equipment, HVAC cooling/heating contributions, and heat loss through the building envelope. The CO₂ model uses mass balance equations: class AirQualityModel { static calculateCO2Change(zone, delta_t_seconds) { // CO₂ generation from occupants const G_co2 = zone.occupancy * 0.0052; // L/s per person at rest // Outdoor air ventilation rate const V_oa = zone.vav.outdoor_air_cfm * 0.000471947; // CFM to m³/s // CO₂ concentration difference (indoor - outdoor) const delta_CO2 = zone.co2_ppm - 400; // Outdoor ~400ppm // Mass balance: dC/dt = (G - V*ΔC) / Volume const dCO2_dt = (G_co2 - V_oa * delta_CO2) / zone.volume; return zone.co2_ppm + (dCO2_dt * delta_t_seconds); } } These models execute every simulation step, updating the entire building state: async function simulateStep(twin, timestep_minutes) { const delta_t = timestep_minutes * 60; // Convert to seconds // Update each zone for (const zone of twin.zones) { zone.temperature = ZoneThermalModel.calculateTemperatureChange(zone, delta_t); zone.co2_ppm = AirQualityModel.calculateCO2Change(zone, delta_t); } // Update equipment based on zone demands for (const vav of twin.vavs) { updateVAVOperation(vav, twin.zones); } for (const ahu of twin.ahus) { updateAHUOperation(ahu, twin.vavs); } updateChillerOperation(twin.chiller, twin.ahus); updateBoilerOperation(twin.boiler, twin.ahus); // Calculate system KPIs twin.kpis = calculateSystemKPIs(twin); // Detect alerts twin.alerts = detectAnomalies(twin); // Persist updated state await saveTwinState(twin); return twin; } 3D Visualization with React and Three.js The frontend renders an interactive 3D building view that updates in real-time as conditions change. Using React Three Fiber simplifies Three.js integration with React's component model: // frontend/src/components/BuildingView3D.jsx import { Canvas } from '@react-three/fiber'; import { OrbitControls } from '@react-three/drei'; export function BuildingView3D({ twinState }) { return ( {/* Render building floors */} {twinState.zones.map(zone => ( selectZone(zone.id)} /> ))} {/* Render equipment */} {twinState.ahus.map(ahu => ( ))} ); } function ZoneMesh({ zone, onClick }) { const color = getTemperatureColor(zone.temperature, zone.setpoint); return ( ); } function getTemperatureColor(current, setpoint) { const deviation = current - setpoint; if (Math.abs(deviation) < 1) return '#00ff00'; // Green: comfortable if (Math.abs(deviation) < 3) return '#ffff00'; // Yellow: acceptable return '#ff0000'; // Red: uncomfortable } This visualization immediately shows building state at a glance, operators see "hot spots" in red, comfortable zones in green, and can click any area for detailed metrics. Integrating AI Copilot for Natural Language Control The AI copilot transforms building data into conversational insights. Instead of navigating multiple screens, operators simply ask questions: // backend/src/routes/copilot.js import { FoundryLocalClient } from 'foundry-local-sdk'; const foundry = new FoundryLocalClient({ endpoint: process.env.FOUNDRY_LOCAL_ENDPOINT }); router.post('/api/copilot/chat', async (req, res) => { const { message } = req.body; // Load current building state const twin = await loadTwinState(); // Build context for AI const context = buildBuildingContext(twin); const completion = await foundry.chat.completions.create({ model: 'phi-4', messages: [ { role: 'system', content: `You are an HVAC operations assistant for a 3-floor office building. Current Building State: ${context} Answer questions about equipment status, comfort conditions, and energy usage. Provide specific, actionable information based on the current data. Do not speculate beyond provided information.` }, { role: 'user', content: message } ], temperature: 0.3, max_tokens: 300 }); res.json({ response: completion.choices[0].message.content, model: 'phi-4', timestamp: new Date().toISOString() }); }); function buildBuildingContext(twin) { const alerts = twin.alerts.filter(a => a.active); const zoneStatus = twin.zones.map(z => `${z.name}: ${z.temperature.toFixed(1)}°F (setpoint: ${z.setpoint}°F), CO₂: ${z.co2_ppm}ppm, ${z.occupancy} people` ); return ` Zones: ${zoneStatus.join('\n')} Active Alerts: ${alerts.length} ${alerts.map(a => `- ${a.severity}: ${a.message}`).join('\n')} Energy: ${twin.kpis.total_power_kw.toFixed(1)} kW Chiller: ${twin.chiller.percent_load}% load, ${twin.chiller.cop.toFixed(2)} COP `.trim(); } Example interactions: User: "Why is the third floor conference room warm?" AI: "The Executive Suite on Floor 3 is currently 75.2°F, 3 degrees above the 72°F setpoint. This is due to high occupancy (8 people) and VAV-F3-EXEC operating at reduced airflow (285 CFM vs 450 CFM capacity). AHU-2 is supplying adequate cool air at 55°F. Recommend checking VAV damper position—it may be partially stuck." User: "What's our current energy usage?" AI: "Total building power consumption is 47.3 kW. Breakdown: Chiller (24.1 kW, 51%), AHU fans (12.8 kW, 27%), Pumps (7.2 kW, 15%), Other (3.2 kW, 7%). Chiller is operating at 62% load with a COP of 4.8, which is efficient for current conditions." User: "Activate demand response level 2" AI: "I cannot directly control building systems for safety reasons. To activate DR Level 2, use the Control Panel and click 'Demand Response' → 'Level 2'. This will raise cooling setpoints by 3°F and reduce auxiliary loads, targeting 15% energy reduction." The AI provides grounded, specific answers citing actual equipment IDs and metrics. It refuses to directly execute control commands, instead guiding operators to explicit control interfaces, a critical safety pattern for building systems. Fault Injection for Testing and Training Real building operations experience equipment failures, stuck dampers, sensor drift, communication losses. The digital twin includes comprehensive fault injection capabilities to train operators and test control logic: // backend/src/simulator/fault-injector.js const FAULT_CATALOG = { chillerFailure: { description: 'Chiller compressor failure', apply: (twin) => { twin.chiller.status = 'FAULT'; twin.chiller.cooling_output = 0; twin.alerts.push({ id: 'chiller-fault', severity: 'CRITICAL', message: 'Chiller compressor failure - no cooling available', equipment: 'CHILLER-01' }); } }, stuckVAVDamper: { description: 'VAV damper stuck at current position', apply: (twin, vavId) => { const vav = twin.vavs.find(v => v.id === vavId); vav.damper_stuck = true; vav.damper_position_fixed = vav.damper_position; twin.alerts.push({ id: `vav-stuck-${vavId}`, severity: 'HIGH', message: `VAV ${vavId} damper stuck at ${vav.damper_position}%`, equipment: vavId }); } }, sensorDrift: { description: 'Temperature sensor reading 5°F high', apply: (twin, zoneId) => { const zone = twin.zones.find(z => z.id === zoneId); zone.sensor_drift = 5.0; zone.temperature_measured = zone.temperature_actual + 5.0; } }, communicationLoss: { description: 'Equipment communication timeout', apply: (twin, equipmentId) => { const equipment = findEquipmentById(twin, equipmentId); equipment.comm_status = 'OFFLINE'; equipment.stale_data = true; twin.alerts.push({ id: `comm-loss-${equipmentId}`, severity: 'MEDIUM', message: `Lost communication with ${equipmentId}`, equipment: equipmentId }); } } }; router.post('/api/twin/fault', async (req, res) => { const { faultType, targetEquipment } = req.body; const twin = await loadTwinState(); const fault = FAULT_CATALOG[faultType]; if (!fault) { return res.status(400).json({ error: 'Unknown fault type' }); } fault.apply(twin, targetEquipment); await saveTwinState(twin); res.json({ message: `Applied fault: ${fault.description}`, affectedEquipment: targetEquipment, timestamp: new Date().toISOString() }); }); Operators can inject faults to practice diagnosis and response. Training scenarios might include: "The chiller just failed during a heat wave, how do you maintain comfort?" or "Multiple VAV dampers are stuck, which zones need immediate attention?" Key Takeaways and Production Deployment Building a physics-based digital twin with AI capabilities requires balancing simulation accuracy with computational performance, providing intuitive visualization while maintaining technical depth, and enabling AI assistance without compromising safety. Key architectural lessons: Physics models enable prediction: Comparing predicted vs observed behavior identifies anomalies that simple thresholds miss 3D visualization improves spatial understanding: Operators immediately see which floors or zones need attention AI copilots accelerate diagnosis: Natural language queries get answers in seconds vs. minutes of manual data examination Fault injection validates readiness: Testing failure scenarios prepares operators for real incidents JSON state enables integration: Simple file-based state makes connecting to real BMS systems straightforward For production deployment, connect the twin to actual building systems via BACnet, Modbus, or MQTT integrations. Replace simulated telemetry with real sensor streams. Calibrate model parameters against historical building performance. Implement continuous learning where the twin's predictions improve as it observes actual building behavior. The complete implementation with simulation engine, 3D visualization, AI copilot, and fault injection system is available at github.com/leestott/DigitalTwin. Clone the repository and run the startup scripts to explore the digital twin, no building hardware required. Resources and Further Reading Smart Building HVAC Digital Twin Repository - Complete source code and simulation engine Setup and Quick Start Guide - Installation instructions and usage examples Microsoft Foundry Local Documentation - AI integration reference HVAC Simulation Documentation - Physics model details and calibration Three.js Documentation - 3D visualization framework ASHRAE Standards - Building energy modeling standardsLearn how to build MCP servers with Python and Azure
We just concluded Python + MCP, a three-part livestream series where we: Built MCP servers in Python using FastMCP Deployed them into production on Azure (Container Apps and Functions) Added authentication, including Microsoft Entra as the OAuth provider All of the materials from our series are available for you to keep learning from, and linked below: Video recordings of each stream Powerpoint slides Open-source code samples complete with Azure infrastructure and 1-command deployment If you're an instructor, feel free to use the slides and code examples in your own classes. Spanish speaker? We've got you covered- check out the Spanish version of the series. 🙋🏽‍♂️Have follow up questions? Join our weekly office hours on Foundry Discord: Tuesdays @ 11AM PT → Python + AI Thursdays @ 8:30 AM PT → All things MCP Building MCP servers with FastMCP 📺 Watch YouTube recording In the intro session of our Python + MCP series, we dive into the hottest technology of 2025: MCP (Model Context Protocol). This open protocol makes it easy to extend AI agents and chatbots with custom functionality, making them more powerful and flexible. We demonstrate how to use the Python FastMCP SDK to build an MCP server running locally. Then we consume that server from chatbots like GitHub Copilot in VS Code, using it's tools, resources, and prompts. Finally, we discover how easy it is to connect AI agent frameworks like Langchain and Microsoft agent-framework to the MCP server. Slides for this session Code repository with examples: python-mcp-demos Deploying MCP servers to the cloud 📺 Watch YouTube recording In our second session of the Python + MCP series, we deploy MCP servers to the cloud! We walk through the process of containerizing a FastMCP server with Docker and deploying to Azure Container Apps. Then we instrument the MCP server with OpenTelemetry and observe the tool calls using Azure Application Insights and Logfire. Finally, we explore private networking options for MCP servers, using virtual networks that restrict external access to internal MCP tools and agents. Slides for this session Code repository with examples: python-mcp-demos Authentication for MCP servers 📺 Watch YouTube recording In our third session of the Python + MCP series, we explore the best ways to build authentication layers on top of your MCP servers. We start off simple, with an API key to gate access, and demonstrate a key-restricted FastMCP server deployed to Azure Functions. Then we move on to OAuth-based authentication for MCP servers that provide user-specific data. We dive deep into MCP authentication, which is built on top of OAuth2 but with additional requirements like PRM and DCR/CIMD, which can make it difficult to implement fully. We demonstrate the full MCP auth flow in the open-souce identity provider KeyCloak, and show how to use an OAuth proxy pattern to implement MCP auth on top of Microsoft Entra. Slides for this session Code repository with Container Apps examples: python-mcp-demos Code repository with Functions examples: python-mcp-demosIf You're Building AI on Azure, ECS 2026 is Where You Need to Be
Let me be direct: there's a lot of noise in the conference calendar. Generic cloud events. Vendor showcases dressed up as technical content. Sessions that look great on paper but leave you with nothing you can actually ship on Monday. ECS 2026 isn't that. As someone who will be on stage at Cologne this May, I can tell you the European Collaboration Summit combined with the European AI & Cloud Summit and European Biz Apps Summit is one of the few events I've seen where engineers leave with real, production-applicable knowledge. Three days. Three summits. 3,000+ attendees. One of the largest Microsoft-focused events in Europe, and it keeps getting better. If you're building AI systems on Azure, designing cloud-native architectures, or trying to figure out how to take your AI experiments to production — this is where the conversation is happening. What ECS 2026 Actually Is ECS 2026 runs May 5–7 at Confex in Cologne, Germany. It brings together three co-located summits under one roof: European Collaboration Summit — Microsoft 365, Teams, Copilot, and governance European AI & Cloud Summit — Azure architecture, AI agents, cloud security, responsible AI European BizApps Summit — Power Platform, Microsoft Fabric, Dynamics For Azure engineers and AI developers, the European AI & Cloud Summit is your primary destination. But don't ignore the overlap, some of the most interesting AI conversations happen at the intersection of collaboration tooling and cloud infrastructure. The scale matters here: 3,000+ attendees, 100+ sessions, multiple deep-dive tracks, and a speaker lineup that includes Microsoft executives, Regional Directors, and MVPs who have built, broken, and rebuilt production systems. The Azure + AI Track - What's Actually On the Agenda The AI & Cloud Summit agenda is built around real technical depth. Not "intro to AI" content, actual architecture decisions, patterns that work, and lessons from things that didn't. Here's what you can expect: AI Agents and Agentic Systems This is where the energy is right now, and ECS is leaning in. Expect sessions covering how to design agent workflows, chain reasoning steps, handle memory and state, and integrate with Azure AI services. Marco Casalaina, VP of Products for Azure AI at Microsoft, is speaking if you want to understand the direction of the Azure AI platform from the people building it, this is a direct line. Azure Architecture at Scale Cloud-native patterns, microservices, containers, and the architectural decisions that determine whether your system holds up under real load. These sessions go beyond theory you'll hear from engineers who've shipped these designs at enterprise scale. Observability, DevOps, and Production AI Getting AI to production is harder than the demos suggest. Sessions here cover monitoring AI systems, integrating LLMs into CI/CD pipelines, and building the operational practices that keep AI in production reliable and governable. Cloud Security and Compliance Security isn't optional when you're putting AI in front of users or connecting it to enterprise data. Tracks cover identity, access patterns, responsible AI governance, and how to design systems that satisfy compliance requirements without becoming unmaintainable. Pre-Conference Deep Dives One underrated part of ECS: the pre-conference workshops. These are extended, hands-on sessions typically 3–6 hours that let you go deep on a single topic with an expert. Think of them as intensive short courses where you can actually work through the material, not just watch slides. If you're newer to a particular area of Azure AI, or you want to build fluency in a specific pattern before the main conference sessions, these are worth the early travel. The Speaker Quality Is Different Here The ECS speaker roster includes Microsoft executives, Microsoft MVPs, and Regional Directors, people who have real accountability for the products and patterns they're presenting. You'll hear from over 20 Microsoft speakers: Marco Casalaina — VP of Products, Azure AI at Microsoft Adam Harmetz — VP of Product at Microsoft, Enterprise Agent And dozens of MVPs and Regional Directors who are in the field every day, solving the same problems you are. These aren't keynote-only speakers — they're in the session rooms, at the hallway track, available for real conversations. The Hallway Track Is Not a Cliché I know "networking" sounds like a corporate afterthought. At ECS it genuinely isn't. When you put 3,000 practitioners, engineers, architects, DevOps leads, security specialists in one venue for three days, the conversations between sessions are often more valuable than the sessions themselves. You get candid answers to "how are you actually handling X in production?" that you won't find in documentation. The European Microsoft community is tight-knit and collaborative. ECS is where that community concentrates. Why This Matters Right Now We're in a period where AI development is moving fast but the engineering discipline around it is still maturing. Most teams are figuring out: How to move from AI prototype to production system How to instrument and observe AI behaviour reliably How to design agent systems that don't become unmaintainable How to satisfy security and compliance requirements in AI-integrated architectures ECS 2026 is one of the few places where you can get direct answers to these questions from people who've solved them — not theoretically, but in production, on Azure, in the last 12 months. If you go, you'll come back with practical patterns you can apply immediately. That's the bar I hold events to. ECS consistently clears it. Register and Explore the Agenda Register for ECS 2026: ecs.events Explore the AI & Cloud Summit agenda: cloudsummit.eu/en/agenda Dates: May 5–7, 2026 | Location: Confex, Cologne, Germany Early registration is worth it the pre-conference workshops fill up. And if you're coming, find me, I'll be the one talking too much about AI agents and Azure deployments. See you in Cologne.Giving Your AI Agents Reliable Skills with the Agent Skills SDK
AI agents are becoming increasingly capable, but they often do not have the context they need to do real work reliably. Your agent can reason well, but it does not actually know how to do the specific things your team needs it to do. For example, it cannot follow your company's incident response playbook, it does not know your escalation policy, and it has no idea how to page the on-call engineer at 3 AM. There are many ways to close this gap, from RAG to custom tool implementations. Agent Skills is one approach that stands out because it is designed around portability and progressive disclosure, keeping context window usage minimal while giving agents access to deep expertise on demand. What is Agent Skills? Agent Skills is an open format for giving agents new capabilities and expertise. The format was originally developed by Anthropic and released as an open standard. It is now supported by a growing list of agent products including Claude Code, VS Code, GitHub, OpenAI Codex, Cursor, Gemini CLI, and many others. As defined in the spec, a skill is a folder on disk containing a SKILL.md file with metadata and instructions, plus optional scripts, references, and assets: incident-response/ SKILL.md # Required: instructions + metadata references/ # Optional: additional documentation severity-levels.md escalation-policy.md scripts/ # Optional: executable code page-oncall.sh assets/ # Optional: templates, diagrams, data files The SKILL.md file has YAML frontmatter with a name and description (so agents know when the skill is relevant), followed by markdown instructions that tell the agent how to perform the task. The format is intentionally simple: self-documenting, extensible, and portable. What makes this design practical is progressive disclosure. The spec is built around the idea that agents should not load everything at once. It works in three stages: Discovery: At startup, agents load only the name and description of each available skill, just enough to know when it might be relevant. Activation: When a task matches a skill's description, the agent reads the full SKILL.md instructions into context. Execution: The agent follows the instructions, optionally loading referenced files or executing bundled scripts as needed. This keeps agents fast while giving them access to deep context on demand. The format is well-designed and widely adopted, but if you want to use skills from your own agents, there is a gap between the spec and a working implementation. The Agent Skills SDK Conceptually, a skill is more than a folder. It is a unit of expertise: a name, a description, a body of instructions, and a set of supporting resources. The file layout is one way to represent that, but there is nothing about the concept that requires a filesystem. The Agent Skills SDK is an open-source Python library built around that idea, treating skills as abstract units of expertise that can be stored anywhere and consumed by any agent framework. It does this by addressing two challenges that come up when you try to use the format from your own agents. The first is where skills live. The spec defines skills as folders on disk, and the tools that support the format today all assume skills are local files. Files are inherently portable, and that is one of the format's strengths. But in the real world, not every team can or wants to serve skills from the filesystem. Maybe your team keeps them in an S3 bucket. Maybe they are in Azure Blob Storage behind your CDN. Maybe they live in a database alongside the rest of your application data. At the moment, if your skills are not on the local filesystem, you are on your own. The SDK changes where skills are served from, not how they are authored. The content and format stay the same regardless of the storage backend, so skills remain portable across providers. The second is how agents consume them. The spec defines the progressive disclosure pattern but actually implementing it in your agent requires real work. You need to figure out how to validate skills against the spec, generate a catalog for the system prompt, expose the right tools for on-demand content retrieval, and handle the back-and-forth of the agent requesting metadata, then the body, then individual references or scripts. That is a lot of plumbing regardless of where the skills are stored, and the work multiplies if you want to support more than one agent framework. The SDK solves both by separating where skills come from (providers) from how agents use them (integrations), so you can mix and match freely. Load skills from the filesystem today, move them to an HTTP server tomorrow, swap in a custom database provider next month, and your agent code does not change at all. How the SDK works The SDK is a set of Python packages organized around two ideas: storage-agnostic providers and progressive disclosure. The provider abstraction means your skills can live anywhere. The SDK ships with providers for the local filesystem and static HTTP servers, but the SkillProvider interface is simple enough that you can write your own in a few methods. A Cosmos DB provider, a Git provider, a SharePoint provider, whatever makes sense for your team. The rest of the SDK does not care where the data comes from. On top of that, the SDK implements the progressive disclosure pattern from the spec as a set of tools that any LLM agent can use. At startup, the SDK generates a skills catalog containing each skill's name and description. Your agent injects this catalog into its system prompt so it knows what is available. Then, during a conversation, the agent calls tools to retrieve content on demand, following the same discovery-activation-execution flow the spec describes. Here is the flow in practice: You register skills from any source (local files, an HTTP server, your own database). The SDK generates a catalog and tool usage instructions, which you inject into the system prompt. The agent calls tools to retrieve content on demand. This matters because context windows are finite. An incident response skill might have a main body, three reference documents, two scripts, and a flowchart. The agent should not load all of that upfront. It should read the body first, then pull the escalation policy only when the conversation actually gets to escalation. A quick example Here is what it looks like in practice. Start by loading a skill from the filesystem: from pathlib import Path from agentskills_core import SkillRegistry from agentskills_fs import LocalFileSystemSkillProvider provider = LocalFileSystemSkillProvider(Path("my-skills")) registry = SkillRegistry() await registry.register("incident-response", provider) Now wire it into a LangChain agent: from langchain.agents import create_agent from agentskills_langchain import get_tools, get_tools_usage_instructions tools = get_tools(registry) skills_catalog = await registry.get_skills_catalog(format="xml") tool_usage_instructions = get_tools_usage_instructions() system_prompt = ( "You are an SRE assistant. Use the available skill tools to look up " "incident response procedures, severity definitions, and escalation " "policies. Always cite which reference document you used.\n\n" f"{skills_catalog}\n\n" f"{tool_usage_instructions}" ) agent = create_agent( llm, tools, system_prompt=system_prompt, ) That is it. The agent now knows what skills are available and has tools to fetch their content. When a user asks "How do I handle a SEV1 incident?", the agent will call get_skill_body to read the instructions, then get_skill_reference to pull the severity levels document, all without you writing any of that retrieval logic. The same pattern works with Microsoft Agent Framework: from agentskills_agentframework import get_tools, get_tools_usage_instructions tools = get_tools(registry) skills_catalog = await registry.get_skills_catalog(format="xml") tool_usage_instructions = get_tools_usage_instructions() system_prompt = ( "You are an SRE assistant. Use the available skill tools to look up " "incident response procedures, severity definitions, and escalation " "policies. Always cite which reference document you used.\n\n" f"{skills_catalog}\n\n" f"{tool_usage_instructions}" ) agent = Agent( client=client, instructions=system_prompt, tools=tools, ) What is in the SDK The SDK is split into small, composable packages so you only install what you need: agentskills-core handles registration, validation, the skills catalog, and the progressive disclosure API. It also defines the SkillProvider interface that all providers implement. agentskills-fs and agentskills-http are the two built-in providers. The filesystem provider loads skills from local directories. The HTTP provider loads them from any static file host: S3, Azure Blob Storage, GitHub Pages, a CDN, or anything that serves files over HTTP. agentskills-langchain and agentskills-agentframework generate framework-native tools and tool usage instructions from a skill registry. agentskills-mcp-server spins up an MCP server that exposes skill tool access and usage as tools and resources, so any MCP-compatible client can use them. Because providers and integrations are separate packages, you can combine them however you want. Use the filesystem provider during development, switch to the HTTP provider in production, or write a custom provider that reads skills from your own database. The integration layer does not need to know or care. Where to go from here The full source, working examples, and detailed API docs are on GitHub: github.com/pratikxpanda/agentskills-sdk The repo includes end-to-end examples for both LangChain and Microsoft Agent Framework, covering filesystem providers, HTTP providers, and MCP. There is also a sample incident-response skill you can use to try things out. A proposal to contribute this SDK to the official agentskills repository has been submitted. If you find it useful, feel free to show your support on the GitHub issue. To learn more about the Agent Skills format itself: What are skills? covers the format and why it matters. Specification is the complete format reference for SKILL.md files. Integrate skills explains how to add skills support to your agent. Example skills on GitHub are a good starting point for writing your own. The SDK is MIT licensed and contributions are welcome. If you have questions or ideas, post a question here or open an issue on the repo.Learn MCP from our free livestream series in December
Our Python + MCP series is a three-part, hands-on journey into one of the most important emerging technologies of 2025: MCP (Model Context Protocol) — an open standard for extending AI agents and chat interfaces with real-world tools, data, and execution environments. Whether you're building custom GitHub Copilot tools, powering internal developer agents, or creating AI-augmented applications, MCP provides the missing interoperability layer between LLMs and the systems they need to act on. Across the series, we move from local prototyping, to cloud deployment, to enterprise-grade authentication and security, all powered by Python and the FastMCP SDK. Each session builds on the last, showing how MCP servers can evolve from simple localhost services to fully authenticated, production-ready services running in the cloud — and how agents built with frameworks like Langchain and Microsoft’s agent-framework can consume them at every stage. 🔗 Register for the entire series. You can also scroll down to learn about each live stream and register for individual sessions. In addition to the live streams, you can also join office hours after each session in Foundry Discord to ask any follow-up questions. To get started with your MCP learnings before the series, check out the free MCP-for-beginners course on GitHub. Building MCP servers with FastMCP 16 December, 2025 | 6:00 PM - 7:00 PM (UTC) Coordinated Universal Time Register for the stream on Reactor In the intro session of our Python + MCP series, we dive into the hottest technology of 2025: MCP (Model Context Protocol). This open protocol makes it easy to extend AI agents and chatbots with custom functionality, making them more powerful and flexible. We demonstrate how to use the Python FastMCP SDK to build an MCP server running locally and consume that server from chatbots like GitHub Copilot. Then we build our own MCP client to consume the server. Finally, we discover how easy it is to connect AI agent frameworks like Langchain and Microsoft agent-framework to MCP servers. Deploying MCP servers to the cloud 17 December, 2025 | 6:00 PM - 7:00 PM (UTC) Coordinated Universal Time Register for the stream on Reactor In our second session of the Python + MCP series, we're deploying MCP servers to the cloud! We'll walk through the process of containerizing a FastMCP server with Docker and deploying to Azure Container Apps, and also demonstrate a FastMCP server running directly on Azure Functions. Then we'll explore private networking options for MCP servers, using virtual networks that restrict external access to internal MCP tools and agents. Authentication for MCP servers 18 December, 2025 | 6:00 PM - 7:00 PM (UTC) Coordinated Universal Time Register for the stream on Reactor In our third session of the Python + MCP series, we're exploring the best ways to build authentication layers on top of your MCP servers. That could be as simple as an API key to gate access, but for the servers that provide user-specific data, we need to use an OAuth2-based authentication flow. MCP authentication is built on top of OAuth2 but with additional requirements like PRM and DCR/CIMD, which can make it difficult to implement fully. In this session, we'll demonstrate the full MCP auth flow, and provide examples that implement MCP Auth on top of Microsoft Entra.Agents League: The Esports-Inspired Hackathon Where AI Agents Battle for Glory
Ready to put your AI skills to the ultimate test? Agents League is here, a dynamic, esports-inspired developer challenge that brings the thrill of live competition to the world of agentic AI. Whether you're a seasoned AI developer or just getting started, this is your chance to build, compete, and win. What is Agents League? Agents League is a week-long hackathon running as part of AI Skills Fest (June 4–14, 2026). Unlike traditional hackathons, Agents League combines live AI coding battles, asynchronous project submissions, and a thriving Discord community all competing for a total prize pool of $55,000 USD. This isn't just about building it's about showcasing what's possible with agentic AI in a format that's fast, competitive, and globally accessible. Three Challenge Tracks Pick One or Compete in All 1. Creative Apps Build innovative applications using GitHub Copilot for AI-assisted development. Show off your creativity and demonstrate how AI can accelerate app creation from concept to code. 2. Reasoning Agents Create intelligent agents using Microsoft Foundry that solve complex problems through multi-step reasoning. This track is all about building agents that can think, plan, and execute. 3. Enterprise Agents Build business-ready knowledge agents integrated with Microsoft 365 Copilot, authored in Copilot Studio. Perfect for developers focused on real-world enterprise solutions. Live Microsoft Reactor Events—Don't Miss the Battles! The heart of Agents League beats through live Microsoft Reactor events. Watch experts go head-to-head in live coding battles, learn cutting-edge techniques, and get inspired for your own submissions: Event What You'll Learn Creative Apps Battle See GitHub Copilot in action as experts build innovative apps live Reasoning Agents Battle Watch multi-step reasoning agents come to life with Microsoft Foundry Enterprise Agents Battle Learn to build M365-integrated agents with Copilot Studio 👉 View the full event series Key Dates Registration Deadline: June 12, 2026, 12:00 PM PT Hacking Period: June 4–14, 2026 Submission Deadline: June 14, 2026, 11:59 PM PT What You Get Live coding battles with expert demonstrations Curated technical experiences and on-demand content Learning resources on Microsoft Learn and AI Skills Navigator Community support through Discord GitHub-based submissions for transparent, collaborative judging Why Participate? Agents League isn't just another hackathon. It's designed as a streamlined, competitive format that: ✅ Fits into your schedule with focused, time-boxed challenges ✅ Provides real-world product innovation experience ✅ Offers global accessibility—participate from anywhere ✅ Demonstrates the latest capabilities of agentic AI, including new IQ tools ✅ Connects you with a passionate developer community Ready to Enter the Arena? Register Now for Agents League Before you register: Review the Hackathon Rules and Regulations for prize categories and judging criteria Join the Microsoft Reactor event series for live battles and learning Check out the Microsoft Event Code of Conduct Join the Conversation Have questions? Want to connect with fellow competitors? Join the Agents League community on Discord and start strategizing with developers from around the world. Whether you're building creative apps, reasoning agents, or enterprise solutions—the arena awaits. May the best agent win! 🏆 Agents League hackathon is open to the public and offered at no cost. Government employees should check with their employers to ensure participation is permitted in accordance with applicable policies. Related Links: Agents League Hackathon Registration Microsoft Reactor Series AI Skills FestBuilding MCP servers with Entra ID and pre-authorized clients
The Model Context Protocol (MCP) gives AI agents a standard way to call external tools, but things get more complicated when those tools need to know who the user is. In this post, I’ll show how to build an MCP server with the Python FastMCP package that authenticates users with Microsoft Entra ID when they connect from a pre-authorized client such as VS Code. If you need to build a server that works with any MCP clients, read my previous blog post. With Microsoft Entra as the authorization server, supporting arbitrary clients currently requires adding an OAuth proxy in front, which increases security risk. This post focuses on the simpler pre-authorized-client path instead. MCP auth Let’s start by digging into the MCP auth spec, since that explains both the shape of the flow and the constraints we run into with Entra. The MCP specification includes an authorization protocol based on OAuth 2.1, so an MCP client can send a request that includes a Bearer token from an authorization server, and the MCP server can validate that token. In OAuth 2.1 terms, the MCP client is acting as the OAuth client, the MCP server is the resource server, the signed-in user is the resource owner, and the authorization server issues an access token. In this case, Entra will be our authorization server. We can't necessarily use any OAuth-compatible authorization servers, as MCP auth requires more than just the core OAuth 2.1 functionality. In OAuth, the authorization server needs a relationship with the client. MCP auth describes three options: Pre-registration: the auth server has a pre-existing relationship and has the client ID in its database already CIMD (Client Identity Metadata Document): the MCP client sends the URL of its CIMD, a JSON document that describes its attributes, and the auth server bases its interactions on that information. DCR (Dynamic Client Registration): when the auth server sees a new client, it explicitly registers it and stores the client information in its own data. DCR is now considered a "legacy" path, as the hope is for CIMD to be the supported path in the future. For each MCP scenario - each combination of MCP server, MCP client, and authorization server - we need to determine which of those options are viable and optimal. Here's one way of thinking through it: VS Code supports all of MCP auth, so its MCP client includes both CIMD and DCR support. However, the Microsoft Entra authorization server does not support CIMD or DCR. That leaves us with only one official option: pre-registration. If we desperately need support for arbitrary clients, it is possible to put a CIMD/DCR proxy in front of Entra, as discussed in my previous blog post, but the Entra team discourages that approach due to increased security risks. When using pre-registration, the auth flow is relatively simple (but still complex, because hey, this is OAuth!): User asks to use auth-restricted MCP server MCP client makes a request to MCP server without a bearer token MCP server responds with an HTTP 401 and a pointer to its PRM (Protected Resource Metadata) document MCP client reads PRM to discover the authorization server and options MCP client redirects to authorization server, including its client ID User signs into authorization server Authorization server returns authorization code MCP client exchanges authorization code for access token Authorization server returns access token MCP client re-tries original request, but now with bearer token included MCP server validates bearer token and returns successfully Here's what that looks like: Now let's dig into the code for implementing MCP auth with the pre-registered VS Code client. Registering the MCP server with Entra Before the server can use Entra to authorize users, we need to register the server with Entra via an app registration. We can do registration using the Azure Portal, Azure CLI, Microsoft Graph SDK, or even Bicep. In this case, I use the Python MS Graph SDK as it allows me to specify everything programmatically. First, I create the Entra app registration, specifying the sign-in audience (single-tenant) and configuring the MCP server as a protected resource: scope_id = str(uuid.uuid4()) Application( display_name="Entra App for MCP server", sign_in_audience="AzureADMyOrg", api=ApiApplication( requested_access_token_version=2, oauth2_permission_scopes=[ PermissionScope( admin_consent_description="Allows access to the MCP server as the signed-in user.", admin_consent_display_name="Access MCP Server", id=scope_id, is_enabled=True, type="User", user_consent_description="Allow access to the MCP server on your behalf.", user_consent_display_name="Access MCP Server", value="user_impersonation") ], pre_authorized_applications=[ PreAuthorizedApplication( app_id=VSCODE_CLIENT_ID, delegated_permission_ids=[scope_id], )])) The api parameter is doing the heavy lifting, ensuring that other applications (like VS Code) can request permission to access the server on behalf of a user. Here's what each parameter does: requested_access_token_version=2: Entra ID has two token formats (v1.0 and v2.0). We need v2.0 because that's what FastMCP's token validator expects. oauth2_permission_scopes: This defines a permission called user_impersonation that MCP clients can request when connecting to your server. It's the server saying: "I accept tokens that let an MCP client act on behalf of a signed-in user." Without at least one scope defined, no MCP client can obtain a token for your server — Entra wouldn't know what permission to grant. The name user_impersonation is a convention (we could call it anything), but it clearly signals that the MCP client is accessing your server as the user, not as itself. pre_authorized_applications: This list tells Entra which client applications are pre-approved to request tokens for this server’s API without showing an extra consent prompt to the user. In this case, I list VS Code’s application ID and tie it to the user_impersonation scope, so VS Code can request a token for the MCP server as the signed-in user. Thanks to that configuration, when VS Code requests a token, it will request a token with the scope "api://{app_id}/user_impersonation" , and the FastMCP server will validate that incoming tokens contain that scope. Next, I create a Service Principal for that Entra app registration, which represents the Entra app in my tenant request_principal = ServicePrincipal(app_id=app.app_id, display_name=app.display_name) await graph_client.service_principals.post(request_principal) Securing credentials for Entra app registrations I also need a way for the server to prove that it can use that Entra app registration. There are three options: Client secret: Easiest to set up, but since it's a secret, it must be stored securely, protected carefully, and rotated regularly. Certificate: Stronger than a client secret and generally better suited for production, but it still requires certificate storage, renewal, and lifecycle management. Managed identity as Federated Identity Credential (MI-as-FIC): No stored secret, no certificate to manage, and usually the best choice when your app is hosted on Azure. No support for local development however. I wanted the best of both worlds: easy local development on my machine, but the most secure production story for deployment on Azure Container Apps. So I actually created two Entra app registrations, one for local with client secret, and one for production with managed identity. Here's how I set up the password for the local Entra app: password_credential = await graph_client.applications.by_application_id(app.id).add_password.post( AddPasswordPostRequestBody( password_credential=PasswordCredential(display_name="FastMCPSecret"))) It's a bit trickier to set up the MI-as-FIC, since we first need to provision the managed identity and associate that with our Azure Container Apps resource. I set all of that up in Bicep, and then after provisioning completes, I run this code to configure a FIC using the managed identity: fic = FederatedIdentityCredential( name="miAsFic", issuer=f"https://login.microsoftonline.com/{tenant_id}/v2.0", subject=managed_identity_principal_id, audiences=["api://AzureADTokenExchange"], ) await graph_client.applications.by_application_id( prod_app_id ).federated_identity_credentials.post(fic) Since I now have two Entra app registrations, I make sure that the environment variables in my local .env point to the secret-secured local Entra app registration, and the environment variables on my Azure Container App point to the FIC-secured prod Entra app registration. Granting admin consent This next step is only necessary if the MCP server uses the on-behalf-of (OBO) flow to exchange the incoming access token for a token to a downstream API, such as Microsoft Graph. In this case, my demo server uses OBO so it can query Microsoft Graph to check the signed-in user's group membership. The earlier code added VS Code as a pre-authorized application, but that only allows VS Code to obtain a token for the MCP server itself; it does not grant the MCP server permission to call Microsoft Graph on the user's behalf. Because the MCP sign-in flow in VS Code does not include a separate consent step for those downstream Graph scopes, I grant admin consent up front so the OBO exchange can succeed. This code grants the admin consent to the associated service principal for the Graph API resource and scopes: server_principal = await graph_client.service_principals_with_app_id(app.app_id).get() graph_principal = await graph_client.service_principals_with_app_id( "00000003-0000-0000-c000-000000000000" # Graph API ).get() await graph_client.oauth2_permission_grants.post( OAuth2PermissionGrant( client_id=server_principal.id, consent_type="AllPrincipals", resource_id=graph_principal.id, scope="User.Read email offline_access openid profile", ) ) If our MCP server needed to use an OBO flow with another resource server, we could request additional grants for those resources and scopes. Our Entra app registration is now ready for the MCP server, so let's move on to see the server code. Using FastMCP servers with Entra In our MCP server code, we configure FastMCP's RemoteAuthProvider based on the details from the Entra app registration process: from fastmcp.server.auth import RemoteAuthProvider from fastmcp.server.auth.providers.azure import AzureJWTVerifier verifier = AzureJWTVerifier( client_id=ENTRA_CLIENT_ID, tenant_id=AZURE_TENANT_ID, required_scopes=["user_impersonation"], ) auth = RemoteAuthProvider( token_verifier=verifier, authorization_servers=[f"https://login.microsoftonline.com/{AZURE_TENANT_ID}/v2.0"], base_url=base_url, ) Notice that we do not need to pass in a client secret at this point, even when using the local Entra app registration. FastMCP validates the tokens using Entra's public keys - no Entra app credentials needed. To make it easy for our MCP tools to access an identifier for the currently logged in user, we define a middleware that inspects the claims of the current token using FastMCP's get_access_token() and sets the "oid" (Entra object identifier) in the state: class UserAuthMiddleware(Middleware): def _get_user_id(self): token = get_access_token() if not (token and hasattr(token, "claims")): return None return token.claims.get("oid") async def on_call_tool(self, context: MiddlewareContext, call_next): user_id = self._get_user_id() if context.fastmcp_context is not None: await context.fastmcp_context.set_state("user_id", user_id) return await call_next(context) async def on_read_resource(self, context: MiddlewareContext, call_next): user_id = self._get_user_id() if context.fastmcp_context is not None: await context.fastmcp_context.set_state("user_id", user_id) return await call_next(context) When we initialize the FastMCP server, we set the auth provider and include that middleware: mcp = FastMCP("Expenses Tracker", auth=auth, middleware=[UserAuthMiddleware()]) Now, every request made to the MCP server will require authentication. The server will return a 401 if a valid token isn't provided, and that 401 will prompt the VS Code MCP client to kick off the MCP authorization flow. Inside each tool, we can grab the user id from the state, and use that to customize the response for the user, like to store or query items in a database. MCP.tool async def add_user_expense( date: Annotated[date, "Date of the expense in YYYY-MM-DD format"], amount: Annotated[float, "Positive numeric amount of the expense"], description: Annotated[str, "Human-readable description of the expense"], ctx: Context, ): """Add a new expense to Cosmos DB.""" user_id = await ctx.get_state("user_id") if not user_id: return "Error: Authentication required (no user_id present)" expense_item = { "id": str(uuid.uuid4()), "user_id": user_id, "date": date.isoformat(), "amount": amount, "description": description } await cosmos_container.create_item(body=expense_item) Using OBO flow in FastMCP server Remember when we granted admin consent for the Entra app registration earlier? That means we can use an OBO flow inside the MCP server, to make calls to the Graph API on behalf of the signed-in user. To make it easier to exchange and validate tokens, we use the Python MSAL SDK and configure a ConfidentialClientApplication . When using the local secret-secured Entra app registration, this is all we need to set it up: from msal import ConfidentialClientApplication confidential_client = ConfidentialClientApplication( client_id=entra_client_id, client_credential=os.environ["ENTRA_DEV_CLIENT_SECRET"], authority=f"https://login.microsoftonline.com/{os.environ['AZURE_TENANT_ID']}", token_cache=TokenCache(), ) When using the production FIC-secured Entra app registration, we need a function that returns tokens for the managed identity: from msal import ManagedIdentityClient, TokenCache, UserAssignedManagedIdentity mi_client = ManagedIdentityClient( UserAssignedManagedIdentity(client_id=os.environ["AZURE_CLIENT_ID"]), http_client=requests.Session(), token_cache=TokenCache()) def _get_mi_assertion(): result = mi_client.acquire_token_for_client(resource="api://AzureADTokenExchange") if "access_token" not in result: raise RuntimeError(f"Failed to get MI assertion: {result.get('error_description', 'unknown error')}") return result["access_token"] confidential_client = ConfidentialClientApplication( client_id=entra_client_id, client_credential={"client_assertion": _get_mi_assertion}, authority=f"https://login.microsoftonline.com/{os.environ['AZURE_TENANT_ID']}", token_cache=TokenCache()) Inside any code that requires OBO, we ask MSAL to exchange the MCP access token for a Graph API access token: graph_resource_access_token = confidential_client.acquire_token_on_behalf_of( user_assertion=access_token.token, scopes=["https://graph.microsoft.com/.default"] ) graph_token = graph_resource_access_token["access_token"] Once we successfully acquire the token, we can use that token with the Graph API, for any operations permitted by the scopes in the admin consent granted earlier. For this example, we call the Graph API to check whether the logged in user is a member of a particular Entra group: client = httpx.AsyncClient() url = ("https://graph.microsoft.com/v1.0/me/transitiveMemberOf/microsoft.graph.group" f"?$filter=id eq '{group_id}'&$count=true") response = await client.get( url, headers={ "Authorization": f"Bearer {graph_token}", "ConsistencyLevel": "eventual", }) data = response.json() membership_count = data.get("@odata.count", 0) is_admin = membership_count > 0 FastMCP 3.0 now provides a way to restrict tool visibility based on authorization checks, so I wrapped the above code in a function and set it as the auth constraint for the admin tool: async def require_admin_group(ctx: AuthContext) -> bool: graph_token = exchange_for_graph_token(ctx.token.token) return await check_user_in_group(graph_token, admin_group_id) @mcp.tool(auth=require_admin_group) async def get_expense_stats(ctx: Context): """Get expense statistics. Only accessible to admins.""" ... FastMCP will run that function both when an MCP client requests the list of tools, to determine which tools can be seen by the current user, and again when a user tries to use that tool, for an added just-in-time security check. This is just one way to use an OBO flow however. You can use it directly inside tools, like to query for more details from the Graph API, upload documents to OneDrive/SharePoint/Notes, send emails, etc. All together now For the full code, check out the open source azure-cosmosdb-identity-aware-mcp-server repository. The most relevant files for the Entra authentication setup are: auth_init.py: Creates the Entra app registrations for production and local development, defines the delegated user_impersonation scope, pre-authorizes VS Code, creates the service principal, and grants admin consent for the Microsoft Graph scopes used in the OBO flow. auth_postprovision.py: Adds the federated identity credential (FIC) after deployment so the container app's managed identity can act as the production Entra app without storing a client secret. main.py: Implements the MCP server using FastMCP's RemoteAuthProvider and AzureJWTVerifier for direct Entra authentication, plus OBO-based Microsoft Graph calls for admin group membership checks. As always, please let me know if you have further questions or ideas for other Entra integrations. Acknowledgements: Thank you to Matt Gotteiner for his guidance in implementing the OBO flow and review of the blog post.MCP Demystified: Tools vs Resources vs Prompts Explained Simply
Introduction When developers start working with Model Context Protocol (MCP), one of the most confusing parts is understanding the difference between MCP Tools, Resources, and Prompts. All three are important components in modern AI application development, but they serve completely different purposes. In real-world AI systems like chatbots, AI agents, and copilots, using these components correctly can make your application scalable, clean, and easy to maintain. If used incorrectly, it can lead to confusion, bugs, and poor system design. In this article, we will clearly explain the difference between MCP Tools, Resources, and Prompts in simple words, using real-world examples and practical explanations. This guide is helpful for both beginner and intermediate developers working with AI and MCP. What Are MCP Tools? MCP Tools are functions or services that an AI model can use to perform real-world actions. These actions usually involve doing something outside the AI system, such as calling an API, updating a database, or sending a message. In simple terms, Tools represent what the AI can do. Real-World Analogy Think of MCP Tools like service workers in a company. For example, a delivery person delivers packages, a support agent updates tickets, and a payment system processes transactions. Similarly, MCP Tools perform specific tasks when requested by the AI. Examples of MCP Tools A tool that fetches user details from a database A tool that sends emails or notifications A tool that creates or updates support tickets A tool that calls third-party APIs like payment gateways A tool that triggers workflows in enterprise systems Key Understanding Tools are action-based. They execute operations and return results. Whenever your AI needs to "do something," you should use a Tool. What Are MCP Resources? MCP Resources are data sources that the AI model can access to read information. These are typically read-only and provide context or knowledge to the AI. In simple terms, Resources represent what the AI can read or see. Real-World Analogy Think of MCP Resources like books in a library or documents in a company. You can read and learn from them, but you cannot directly change their content. Examples of MCP Resources A database table containing customer information A knowledge base with FAQs and documentation System logs that track user activity Configuration files or static datasets Company policy documents or guidelines Key Understanding Resources are data-based. They provide information but do not perform any action. Whenever your AI needs information to make a decision, you should use a Resource. What Are MCP Prompts? MCP Prompts are structured instructions or templates that guide how the AI model should think, behave, and respond. In simple terms, Prompts represent how you instruct the AI. Real-World Analogy Think of Prompts like instructions given to an employee. For example, “Write a professional email,” “Summarize this report,” or “Answer politely to the customer.” These instructions shape how the output is generated. Examples of MCP Prompts A prompt to summarize customer feedback A prompt to generate a support response in a polite tone A prompt to analyze data and provide insights A prompt to translate text into another language A prompt to generate code based on requirements Key Understanding Prompts are instruction-based. They define how the AI should process input and generate output. Key Differences Between MCP Tools, Resources, and Prompts Understanding the difference between MCP Tools, Resources, and Prompts is important for building scalable AI systems. Tools vs Resources vs Prompts Tools are used for performing actions Resources are used for reading data Prompts are used for guiding AI behavior Detailed Comparison Tools interact with external systems and can change data or trigger operations Resources only provide data and do not modify anything Prompts control how the AI thinks, responds, and formats its output Comparison Table Aspect MCP Tools MCP Resources MCP Prompts Purpose Perform actions Provide data Guide behavior Nature Active Passive Instructional Usage API calls, updates Data reading AI response generation Output Action result Data Generated content How MCP Tools, Resources, and Prompts Work Together In real-world AI systems, these three components are used together to create powerful workflows. Step-by-Step Flow The user sends a request to the AI system The Prompt defines how the AI should understand and respond The AI fetches required information from Resources If an action is required, the AI uses a Tool The AI combines everything and generates a final response Practical Example Consider an AI customer support system: The Prompt ensures the response is polite and helpful The Resource provides customer history and previous tickets The Tool updates the ticket status or sends an email notification This combination helps build intelligent, real-world AI applications. Advantages of Understanding MCP Concepts Helps developers design clean and scalable AI architecture Improves clarity in system design and reduces confusion Enhances performance by separating responsibilities Makes debugging and maintenance easier Supports faster development of AI-powered applications Common Mistakes Developers Make Using Tools when only data retrieval is needed Treating Resources as editable systems Writing vague or unclear Prompts Mixing responsibilities between Tools, Resources, and Prompts Not structuring MCP components properly in applications Best Practices for Using MCP Tools, Resources, and Prompts Clearly define the role of each component before implementation Use Tools only for actions that change system state or trigger operations Use Resources strictly for reading and retrieving data Write clear, specific, and well-structured Prompts Test Tools, Resources, and Prompts independently before integration Keep your architecture modular and easy to scale Summary Understanding the difference between MCP Tools, Resources, and Prompts is essential for modern AI application development using Model Context Protocol. Tools allow AI systems to perform actions, Resources provide the necessary data, and Prompts guide how the AI behaves and generates responses. When these components are used correctly, developers can build scalable, efficient, and intelligent AI systems. Mastering these MCP concepts will help you design better architectures and create powerful AI-driven applications in today’s evolving technology landscape.Agents League: Two Weeks, Three Tracks, One Challenge
We're inviting all developers to join Agents League, running February 16-27. It's a two-week challenge where you'll build AI agents using production-ready tools, learn from live coding sessions, and get feedback directly from Microsoft product teams. We've put together starter kits for each track to help you get up and running quickly that also includes requirements and guidelines. Whether you want to explore what GitHub Copilot can do beyond autocomplete, build reasoning agents on Microsoft Foundry, or create enterprise integrations for Microsoft 365 Copilot, we have a track for you. Important: Register first to be eligible for prizes and your digital badge. Without registration, you won't qualify for awards or receive a badge when you submit. What Is Agents League? It's a 2-week competition that combines learning with building: 📽️ Live coding battles – Watch Product teams, MVPs and community members tackle challenges in real-time on Microsoft Reactor 💻 Async challenges – Build at your own pace, on your schedule 💬 Discord community – Connect with other participants, join AMAs, and get help when you need it 🏆 Prizes – $500 per track winner, plus GitHub Copilot Pro subscriptions for top picks The Three Tracks 🎨 Creative Apps — Build with GitHub Copilot (Chat, CLI, or SDK) 🧠Reasoning Agents — Build with Microsoft Foundry 💼 Enterprise Agents — Build with M365 Agents Toolkit (or Copilot Studio) More details on each track below, or jump straight to the starter kits. The Schedule Agents League starts on February 16th and runs through Feburary 27th. Within 2 weeks, we host live battles on Reactor and AMA sessions on Discord. Week 1: Live Battles (Feb 17-19) We're kicking off with live coding battles streamed on Microsoft Reactor. Watch experienced developers compete in real-time, explaining their approach and architectural decisions as they go. Tue Feb 17, 9 AM PT — 🎨 Creative Apps battle Wed Feb 18, 9 AM PT — 🧠Reasoning Agents battle Thu Feb 19, 9 AM PT — 💼 Enterprise Agents battle All sessions are recorded, so you can watch on your own schedule. Week 2: Build + AMAs (Feb 24-26) This is your time to build and ask questions on Discord. The async format means you work when it suits you, evenings, weekends, whatever fits your schedule. We're also hosting AMAs on Discord where you can ask questions directly to Microsoft experts and product teams: Tue Feb 24, 9 AM PT — 🎨 Creative Apps AMA Wed Feb 25, 9 AM PT — 🧠Reasoning Agents AMA Thu Feb 26, 9 AM PT — 💼 Enterprise Agents AMA Bring your questions, get help when you're stuck, and share what you're building with the community. Pick Your Track We've created a starter kit for each track with setup guides, project ideas, and example scenarios to help you get started quickly. 🎨 Creative Apps Tool: GitHub Copilot (Chat, CLI, or SDK) Build innovative, imaginative applications that showcase the potential of AI-assisted development. All application types are welcome, web apps, CLI tools, games, mobile apps, desktop applications, and more. The starter kit walks you through GitHub Copilot's different modes and provides prompting tips to get the best results. View the Creative Apps starter kit. 🧠Reasoning Agents Tool: Microsoft Foundry (UI or SDK) and/or Microsoft Agent Framework Build a multi-agent system that leverages advanced reasoning capabilities to solve complex problems. This track focuses on agents that can plan, reason through multi-step problems, and collaborate. The starter kit includes architecture patterns, reasoning strategies (planner-executor, critic/verifier, self-reflection), and integration guides for tools and MCP servers. View the Reasoning Agents starter kit. 💼 Enterprise Agents Tool: M365 Agents Toolkit or Copilot Studio Create intelligent agents that extend Microsoft 365 Copilot to address real-world enterprise scenarios. Your agent must work on Microsoft 365 Copilot Chat. Bonus points for: MCP server integration, OAuth security, Adaptive Cards UI, connected agents (multi-agent architecture). View the Enterprise Agents starter kit. Prizes & Recognition To be eligible for prizes and your digital badge, you must register before submitting your project. Category Winners ($500 each): 🎨 Creative Apps winner 🧠Reasoning Agents winner 💼 Enterprise Agents winner GitHub Copilot Pro subscriptions: Community Favorite (voted by participants on Discord) Product Team Picks (selected by Microsoft product teams) Everyone who registers and submits a project wins: A digital badge to showcase their participation. Beyond the prizes, every participant gets feedback from the teams who built these tools, a valuable opportunity to learn and improve your approach to AI agent development. How to Get Started Register first — This is required to be eligible for prizes and to receive your digital badge. Without registration, your submission won't qualify for awards or a badge. Pick a track — Choose one track. Explore the starter kits to help you decide. Watch the battles — See how experienced developers approach these challenges. Great for learning even if you're still deciding whether to compete. Build your project — You have until Feb 27. Work on your own schedule. Submit via GitHub — Open an issue using the project submission template. Join us on Discord — Get help, share your progress, and vote for your favorite projects on Discord. Links Register: https://aka.ms/agentsleague/register Starter Kits: https://github.com/microsoft/agentsleague/starter-kits Discord: https://aka.ms/agentsleague/discord Live Battles: https://aka.ms/agentsleague/battles Submit Project: Project submission template
