Supercharge Your Dev Workflows with GitHub Copilot Custom Skills
The Problem Every team has those repetitive, multi-step workflows that eat up time: Running a sequence of CLI commands, parsing output, and generating a report Querying multiple APIs, correlating data, and summarizing findings Executing test suites, analyzing failures, and producing actionable insights You've probably documented these in a wiki or a runbook. But every time, you still manually copy-paste commands, tweak parameters, and stitch results together. What if your AI coding assistant could do all of that — triggered by a single natural language request? That's exactly what GitHub Copilot Custom Skills enable. What Are Custom Skills? A skill is a folder containing a SKILL.md file (instructions for the AI), plus optional scripts, templates, and reference docs. When you ask Copilot something that matches the skill's description, it loads the instructions and executes the workflow autonomously. Think of it as giving your AI assistant a runbook it can actually execute, not just read. Without Skills With Skills Read the wiki for the procedure Copilot loads the procedure automatically Copy-paste 5 CLI commands Copilot runs the full pipeline Manually parse JSON output Script generates a formatted HTML report 15-30 minutes of manual work One natural language request, ~2 minutes How It Works The key insight: the skill file is the contract between you and the AI. You describe what to do and how, and Copilot handles the orchestration. Prerequisites Requirement Details VS Code Latest stable release GitHub Copilot Active Copilot subscription (Individual, Business, or Enterprise) Agent mode Select "Agent" mode in the Copilot Chat panel (the default in recent versions) Runtime tools Whatever your scripts need — Python, Node.js, .NET CLI, az CLI, etc. Note: Agent Skills follow an open standard — they work across VS Code, GitHub Copilot CLI, and GitHub Copilot coding agent. No additional extensions or cloud services are required for the skill system itself. Anatomy of a Skill .github/skills/my-skill/ ├── SKILL.md # Instructions (required) └── references/ ├── resources/ │ ├── run.py # Automation script │ ├── query-template.sql # Reusable query template │ └── config.yaml # Static configuration └── reports/ └── report_template.html # Output template The SKILL.md File Every skill has the same structure: --- name: my-skill description: 'What this does and when to use it. Include trigger phrases so Copilot knows when to load it. USE FOR: specific task A, task B. Trigger phrases: "keyword1", "keyword2".' argument-hint: 'What inputs the user should provide.' --- # My Skill ## When to Use - Situation A - Situation B ## Quick Start \```powershell cd .github/skills/my-skill/references/resources py run.py <arg1> <arg2> \``` ## What It Does | Step | Action | Purpose | |------|--------|---------| | 1 | Fetch data from source | Gather raw input | | 2 | Process and transform | Apply business logic | | 3 | Generate report | Produce actionable output | ## Output Description of what the user gets back. Key Design Principles Description is discovery. The description field is the only thing Copilot reads to decide whether to load your skill. Pack it with trigger phrases and keywords. Progressive loading. Copilot reads only name + description (~100 tokens) for all skills. It loads the full SKILL.md body only for matched skills. Reference files load only when the procedure references them. Self-contained procedures. Include everything the AI needs to execute — exact commands, parameter formats, file paths. Don't assume prior knowledge. Scripts do the heavy lifting. The AI orchestrates; your scripts execute. This keeps the workflow deterministic and reproducible. Example: Build a Deployment Health Check Skill Let's build a skill that checks the health of a deployment by querying an API, comparing against expected baselines, and generating a summary. Step 1 — Create the folder structure .github/skills/deployment-health/ ├── SKILL.md └── references/ └── resources/ ├── check_health.py └── endpoints.yaml Step 2 — Write the SKILL.md --- name: deployment-health description: 'Check deployment health across environments. Queries health endpoints, compares response times against baselines, and flags degraded services. USE FOR: deployment validation, health check, post-deploy verification, service status. Trigger phrases: "check deployment health", "is the deployment healthy", "post-deploy check", "service health".' argument-hint: 'Provide the environment name (e.g., staging, production).' --- # Deployment Health Check ## When to Use - After deploying to any environment - During incident triage to check service status - Scheduled spot checks ## Quick Start \```bash cd .github/skills/deployment-health/references/resources python check_health.py <environment> \``` ## What It Does 1. Loads endpoint definitions from `endpoints.yaml` 2. Calls each endpoint, records response time and status code 3. Compares against baseline thresholds 4. Generates an HTML report with pass/fail status ## Output HTML report at `references/reports/health_<environment>_<date>.html` Step 3 — Write the script # check_health.py import sys, yaml, requests, time, json from datetime import datetime def main(): env = sys.argv[1] with open("endpoints.yaml") as f: config = yaml.safe_load(f) results = [] for ep in config["endpoints"]: url = ep["url"].replace("{env}", env) start = time.time() resp = requests.get(url, timeout=10) elapsed = time.time() - start results.append({ "service": ep["name"], "status": resp.status_code, "latency_ms": round(elapsed * 1000), "threshold_ms": ep["threshold_ms"], "healthy": resp.status_code == 200 and elapsed * 1000 < ep["threshold_ms"] }) healthy = sum(1 for r in results if r["healthy"]) print(f"Health check: {healthy}/{len(results)} services healthy") # ... generate HTML report ... if __name__ == "__main__": main() Step 4 — Use it Just ask Copilot in agent mode: "Check deployment health for staging" Copilot will: Match against the skill description Load the SKILL.md instructions Run python check_health.py staging Open the generated report Summarize findings in chat More Skill Ideas Skills aren't limited to any specific domain. Here are patterns that work well: Skill What It Automates Test Regression Analyzer Run tests, parse failures, compare against last known-good run, generate diff report API Contract Checker Compare Open API specs between branches, flag breaking changes Security Scan Reporter Run SAST/DAST tools, correlate findings, produce prioritized report Cost Analysis Query cloud billing APIs, compare costs across periods, flag anomalies Release Notes Generator Parse git log between tags, categorize changes, generate changelog Infrastructure Drift Detector Compare live infra state vs IaC templates, flag drift Log Pattern Analyzer Query log aggregation systems, identify anomaly patterns, summarize Performance Bench marker Run benchmarks, compare against baselines, flag regressions Dependency Auditor Scan dependencies, check for vulnerabilities and outdated packages The pattern is always the same: instructions (SKILL.md) + automation script + output template. Tips for Writing Effective Skills Do Front-load the description with keywords — this is how Copilot discovers your skill Include exact commands — cd path/to/dir && python script.py <args> Document input/output clearly — what goes in, what comes out Use tables for multi-step procedures — easier for the AI to follow Include time zone conversion notes if dealing with timestamps Bundle HTML report templates — rich output beats plain text Don't Don't use vague descriptions — "A useful skill" won't trigger on anything Don't assume context — include all paths, env vars, and prerequisites Don't put everything in SKILL.md — use references/ for large files Don't hardcode secrets — use environment variables or Azure Key Vault Don't skip error guidance — tell the AI what common errors look like and how to fix them Skill Locations Skills can live at project or personal level: Location Scope Shared with team? .github/skills/<name>/ Project Yes (via source control) .agents/skills/<name>/ Project Yes (via source control) .claude/skills/<name>/ Project Yes (via source control) ~/.copilot/skills/<name>/ Personal No ~/.agents/skills/<name>/ Personal No ~/.claude/skills/<name>/ Personal No Project-level skills are committed to your repo and shared with the team. Personal skills are yours and roam with your VS Code settings sync. You can also configure additional skill locations via the chat.skillsLocations VS Code setting. How Skills Fit in the Copilot Customization Stack Skills are one of several customization primitives. Here's when to use what: Primitive Use When Workspace Instructions (.github/copilot-instructions.md) Always-on rules: coding standards, naming conventions, architectural guidelines File Instructions (.github/instructions/*.instructions.md) Rules scoped to specific file patterns (e.g., all *.test.ts files) Prompts (.github/prompts/*.prompt.md) Single-shot tasks with parameterized inputs Skills (.github/skills/<name>/SKILL.md) Multi-step workflows with bundled scripts and templates Custom Agents (.github/agents/*.agent.md) Isolated subagents with restricted tool access or multi-stage pipelines Hooks (.github/hooks/*.json) Deterministic shell commands at agent lifecycle events (auto-format, block tools) Plugins Installable skill bundles from the community (awesome-copilot) Slash Commands & Quick Creation Skills automatically appear as slash commands in chat. Type / to see all available skills. You can also pass context after the command: /deployment-health staging /webapp-testing for the login page Want to create a skill fast? Type /create-skill in chat and describe what you need. Copilot will ask clarifying questions and generate the SKILL.md with proper frontmatter and directory structure. You can also extract a skill from an ongoing conversation: after debugging a complex issue, ask "create a skill from how we just debugged that" to capture the multi-step procedure as a reusable skill. Controlling When Skills Load Use frontmatter properties to fine-tune skill availability: Configuration Slash command? Auto-loaded? Use case Default (both omitted) Yes Yes General-purpose skills user-invocable: false No Yes Background knowledge the model loads when relevant disable-model-invocation: true Yes No Skills you only want to run on demand Both set No No Disabled skills The Open Standard Agent Skills follow an open standard that works across multiple AI agents: GitHub Copilot in VS Code — chat and agent mode GitHub Copilot CLI — terminal workflows GitHub Copilot coding agent — automated coding tasks Claude Code, Gemini CLI — compatible agents via .claude/skills/ and .agents/skills/ Skills you write once are portable across all these tools. Getting Started Create .github/skills/<your-skill>/SKILL.md in your repo Write a keyword-rich description in the YAML frontmatter Add your procedure and reference scripts Open VS Code, switch to Agent mode, and ask Copilot to do the task Watch it discover your skill, load the instructions, and execute Or skip the manual setup — type /create-skill in chat and describe what you need. That's it. No extension to install. No config file to update. No deployment pipeline. Just markdown and scripts, version-controlled in your repo. Custom Skills turn your documented procedures into executable AI workflows. Start with your most painful manual task, wrap it in a SKILL.md, and let Copilot handle the rest. Further Reading: Official Agent Skills docs Community skills & plugins (awesome-copilot) Anthropic reference skillsMCP vs mcp-cli: Dynamic Tool Discovery for Token-Efficient AI Agents
Introduction The AI agent ecosystem is evolving rapidly, and with it comes a scaling challenge that many developers are hitting context window bloat. When building systems that integrate with multiple MCP (Model Context Protocol) servers, you're forced to load all tool definitions upfront—consuming thousands of tokens just to describe what tools could be available. mcp-cli: a lightweight tool that changes how we interact with MCP servers. But before diving into mcp-cli, it's essential to understand the foundational protocol itself, the design trade-offs between static and dynamic approaches, and how they differ fundamentally. Part 1: Understanding MCP (Model Context Protocol) What is MCP? The Model Context Protocol (MCP) is an open standard for connecting AI agents and applications to external tools, APIs, and data sources. Think of it as a universal interface that allows: AI Agents (Claude, Gemini, etc.) to discover and call tools Tool Providers to expose capabilities in a standardized way Seamless Integration between diverse systems without custom adapters New to MCP see https://aka.ms/mcp-for-beginners How MCP Works MCP operates on a simple premise: define tools with clear schemas and let clients discover and invoke them. Basic MCP Flow: Tool Provider (MCP Server) ↓ [Tool Definitions + Schemas] ↓ AI Agent / Client ↓ [Discover Tools] → [Invoke Tools] → [Get Results] Example: A GitHub MCP server exposes tools like: search_repositories - Search GitHub repos create_issue - Create a GitHub issue list_pull_requests - List open PRs Each tool comes with a JSON schema describing its parameters, types, and requirements. The Static Integration Problem Traditionally, MCP integration works like this: Startup: Load ALL tool definitions from all servers Context Window: Send every tool schema to the AI model Invocation: Model chooses which tool to call Execution: Tool is invoked and result returned The Problem: When you have multiple MCP servers, the token cost becomes substantial: Scenario Token Count 6 MCP Servers, 60 tools (static loading) ~47,000 tokens After dynamic discovery ~400 tokens Token Reduction 99% 🚀 For a production system with 10+ servers exposing 100+ tools, you're burning through thousands of tokens just describing capabilities, leaving less context for actual reasoning and problem-solving. Key Issues: ❌ Reduced effective context length for actual work ❌ More frequent context compactions ❌ Hard limits on simultaneous MCP servers ❌ Higher API costs Part 2: Enter mcp-cli – Dynamic Context Discovery What is mcp-cli? mcp-cli is a lightweight CLI tool (written in Bun, compiled to a single binary) that implements dynamic context discovery for MCP servers. Instead of loading everything upfront, it pulls in information only when needed. Static vs. Dynamic: The Paradigm Shift Traditional MCP (Static Context): AI Agent Says: "Load all tool definitions from all servers" ↓ Context Window Bloat ❌ ↓ Limited space for reasoning mcp-cli (Dynamic Discovery): AI Agent Says: "What servers exist?" ↓ mcp-cli responds AI Agent Says: "What are the params for tool X?" ↓ mcp-cli responds AI Agent Says: "Execute tool X" mcp-cli executes and responds Result: You only pay for information you actually use. ✅ Core Capabilities mcp-cli provides three primary commands: 1. Discover - What servers and tools exist? mcp-cli Lists all configured MCP servers and their tools. 2. Inspect - What does a specific tool do? mcp-cli info <server> <tool> Returns the full JSON schema for a tool (parameters, descriptions, types). 3. Execute - Run a tool mcp-cli call <server> <tool> '{"arg": "value"}' Executes the tool and returns results. Key Features of mcp-cli Feature Benefit Stdio & HTTP Support Works with both local and remote MCP servers Connection Pooling Lazy-spawn daemon avoids repeated startup overhead Tool Filtering Control which tools are available via allowedTools/disabledTools Glob Searching Find tools matching patterns: mcp-cli grep "*mail*" AI Agent Ready Designed for use in system instructions and agent skills Lightweight Single binary, minimal dependencies Part 3: Detailed Comparison Table Aspect Traditional MCP mcp-cli Protocol HTTP/REST or Stdio Stdio/HTTP (via CLI) Context Loading Static (upfront) Dynamic (on-demand) Tool Discovery All at once Lazy enumeration Schema Inspection Pre-loaded On-request Token Usage High (~47k for 60 tools) Low (~400 for 60 tools) Best For Direct server integration AI agent tool use Implementation Server-side focus CLI-side focus Complexity Medium Low (CLI handles it) Startup Time One call Multiple calls (optimized) Scaling Limited by context Unlimited (pay per use) Integration Custom implementation Pre-built mcp-cli Part 4: When to Use Each Approach Use Traditional MCP (HTTP Endpoints) when: ✅ Building a direct server integration ✅ You have few tools (< 10) and don't care about context waste ✅ You need full control over HTTP requests/responses ✅ You're building a specialized integration (not AI agents) ✅ Real-time synchronous calls are required Use mcp-cli when: ✅ Integrating with AI agents (Claude, Gemini, etc.) ✅ You have multiple MCP servers (> 2-3) ✅ Token efficiency is critical ✅ You want a standardized, battle-tested tool ✅ You prefer CLI-based automation ✅ Connection pooling and lazy loading are beneficial ✅ You're building agent skills or system instructions Conclusion MCP (Model Context Protocol) defines the standard for tool sharing and discovery. mcp-cli is the practical tool that makes MCP efficient for AI agents by implementing dynamic context discovery. The fundamental difference: MCP mcp-cli What The protocol standard The CLI tool Where Both server and client Client-side CLI Problem Solved Tool standardization Context bloat Architecture Protocol Implementation Think of it this way: MCP is the language, mcp-cli is the interpreter that speaks fluently. For AI agent systems, dynamic discovery via mcp-cli is becoming the standard. For direct integrations, traditional MCP HTTP endpoints work fine. The choice depends on your use case, but increasingly, the industry is trending toward mcp-cli for its efficiency and scalability. Resources MCP Specification mcp-cli GitHub New to MCP see https://aka.ms/mcp-for-beginners Practical demo: AnveshMS/mcp-cli-example
Exploring Azure Face API: Facial Landmark Detection and Real-Time Analysis with C#
In today’s world, applications that understand and respond to human facial cues are no longer science fiction—they’re becoming a reality in domains like security, driver monitoring, gaming, and AR/VR. With Azure Face API, developers can leverage powerful cloud-based facial recognition and analysis tools without building complex machine learning models from scratch. In this blog, we’ll explore how to use C# to detect faces, identify key facial landmarks, estimate head pose, track eye and mouth movements, and process real-time video streams. Using OpenCV for visualization, we’ll show how to overlay landmarks, draw bounding boxes, and calculate metrics like Eye Aspect Ratio (EAR) and Mouth Aspect Ratio (MAR)—all in real time. You'll learn to: Set up Azure Face API Detect 27 facial landmarks Estimate head pose (yaw, pitch, roll) Calculate eye aspect ratio (EAR) and mouth openness Draw bounding boxes around features using OpenCV Process real-time video Prerequisites .NET 8 SDK installed Azure subscription with Face API resource Visual Studio 2022 or later Webcam for testing (optional) Basic understanding of C# and computer vision concepts Part 1: Azure Face API Setup 1.1 Install Required NuGet Packages dotnet add package Azure.AI.Vision.Face dotnet add package OpenCvSharp4 dotnet add package OpenCvSharp4.runtime.win 1.2 Create Azure Face API Resource Navigate to Azure Portal Search for "Face" and create a new Face API resource Choose your pricing tier (Free tier: 20 calls/min, 30K calls/month) Copy the Endpoint URL and API Key 1.3 Configure in .NET Application appsettings.json: { "Azure": { "FaceApi": { "Endpoint": "https://your-resource.cognitiveservices.azure.com/", "ApiKey": "your-api-key-here" } } } Initialize Face Client: using Azure; using Azure.AI.Vision.Face; using Microsoft.Extensions.Configuration; public class FaceAnalysisService { private readonly FaceClient _faceClient; private readonly ILogger<FaceAnalysisService> _logger; public FaceAnalysisService(ILogger<FaceAnalysisService> logger, IConfiguration configuration) { _logger = logger; string endpoint = configuration["Azure:FaceApi:Endpoint"]; string apiKey = configuration["Azure:FaceApi:ApiKey"]; _faceClient = new FaceClient(new Uri(endpoint), new AzureKeyCredential(apiKey)); _logger.LogInformation("FaceClient initialized with endpoint: {Endpoint}", endpoint); } } Part 2: Understanding Face Detection Models 2.1 Basic Face Detection public async Task<List<FaceDetectionResult>> DetectFacesAsync(byte[] imageBytes) { using var stream = new MemoryStream(imageBytes); var response = await _faceClient.DetectAsync( BinaryData.FromStream(stream), FaceDetectionModel.Detection03, FaceRecognitionModel.Recognition04, returnFaceId: false, returnFaceAttributes: new FaceAttributeType[] { FaceAttributeType.HeadPose }, returnFaceLandmarks: true, returnRecognitionModel: false ); _logger.LogInformation("Detected {Count} faces", response.Value.Count); return response.Value.ToList(); } Part 3: Facial Landmarks - The 27 Key Points 3.1 Understanding Facial Landmarks 3.2 Accessing Landmarks in Code public void PrintLandmarks(FaceDetectionResult face) { var landmarks = face.FaceLandmarks; if (landmarks == null) { _logger.LogWarning("No landmarks detected"); return; } // Eye landmarks Console.WriteLine($"Left Eye Outer: ({landmarks.EyeLeftOuter.X}, {landmarks.EyeLeftOuter.Y})"); Console.WriteLine($"Left Eye Inner: ({landmarks.EyeLeftInner.X}, {landmarks.EyeLeftInner.Y})"); Console.WriteLine($"Left Eye Top: ({landmarks.EyeLeftTop.X}, {landmarks.EyeLeftTop.Y})"); Console.WriteLine($"Left Eye Bottom: ({landmarks.EyeLeftBottom.X}, {landmarks.EyeLeftBottom.Y})"); // Mouth landmarks Console.WriteLine($"Upper Lip Top: ({landmarks.UpperLipTop.X}, {landmarks.UpperLipTop.Y})"); Console.WriteLine($"Under Lip Bottom: ({landmarks.UnderLipBottom.X}, {landmarks.UnderLipBottom.Y})"); // Nose landmarks Console.WriteLine($"Nose Tip: ({landmarks.NoseTip.X}, {landmarks.NoseTip.Y})"); } 3.3 Visualizing All Landmarks public void DrawAllLandmarks(FaceLandmarks landmarks, Mat frame) { void DrawPoint(FaceLandmarkCoordinate point, Scalar color) { if (point != null) { Cv2.Circle(frame, new Point((int)point.X, (int)point.Y), radius: 3, color: color, thickness: -1); } } // Eyes (Green) DrawPoint(landmarks.EyeLeftOuter, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeLeftInner, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeLeftTop, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeLeftBottom, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeRightOuter, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeRightInner, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeRightTop, new Scalar(0, 255, 0)); DrawPoint(landmarks.EyeRightBottom, new Scalar(0, 255, 0)); // Eyebrows (Cyan) DrawPoint(landmarks.EyebrowLeftOuter, new Scalar(255, 255, 0)); DrawPoint(landmarks.EyebrowLeftInner, new Scalar(255, 255, 0)); DrawPoint(landmarks.EyebrowRightOuter, new Scalar(255, 255, 0)); DrawPoint(landmarks.EyebrowRightInner, new Scalar(255, 255, 0)); // Nose (Yellow) DrawPoint(landmarks.NoseTip, new Scalar(0, 255, 255)); DrawPoint(landmarks.NoseRootLeft, new Scalar(0, 255, 255)); DrawPoint(landmarks.NoseRootRight, new Scalar(0, 255, 255)); DrawPoint(landmarks.NoseLeftAlarOutTip, new Scalar(0, 255, 255)); DrawPoint(landmarks.NoseRightAlarOutTip, new Scalar(0, 255, 255)); // Mouth (Blue) DrawPoint(landmarks.UpperLipTop, new Scalar(255, 0, 0)); DrawPoint(landmarks.UpperLipBottom, new Scalar(255, 0, 0)); DrawPoint(landmarks.UnderLipTop, new Scalar(255, 0, 0)); DrawPoint(landmarks.UnderLipBottom, new Scalar(255, 0, 0)); DrawPoint(landmarks.MouthLeft, new Scalar(255, 0, 0)); DrawPoint(landmarks.MouthRight, new Scalar(255, 0, 0)); // Pupils (Red) DrawPoint(landmarks.PupilLeft, new Scalar(0, 0, 255)); DrawPoint(landmarks.PupilRight, new Scalar(0, 0, 255)); } Part 4: Drawing Bounding Boxes Around Features 4.1 Eye Bounding Boxes /// <summary> /// Draws rectangles around eyes using OpenCV. /// </summary> public void DrawEyeBoxes(FaceLandmarks landmarks, Mat frame) { int boxWidth = 60; int boxHeight = 35; // Calculate Rectangles var leftEyeRect = new Rect((int)landmarks.EyeLeftOuter.X - boxWidth / 2, (int)landmarks.EyeLeftOuter.Y - boxHeight / 2, boxWidth, boxHeight); var rightEyeRect = new Rect((int)landmarks.EyeRightOuter.X - boxWidth / 2, (int)landmarks.EyeRightOuter.Y - boxHeight / 2, boxWidth, boxHeight); // Draw Rectangles (Green in BGR) Cv2.Rectangle(frame, leftEyeRect, new Scalar(0, 255, 0), 2); Cv2.Rectangle(frame, rightEyeRect, new Scalar(0, 255, 0), 2); // Add Labels Cv2.PutText(frame, "Left Eye", new Point(leftEyeRect.X, leftEyeRect.Y - 5), HersheyFonts.HersheySimplex, 0.4, new Scalar(0, 255, 0), 1); Cv2.PutText(frame, "Right Eye", new Point(rightEyeRect.X, rightEyeRect.Y - 5), HersheyFonts.HersheySimplex, 0.4, new Scalar(0, 255, 0), 1); } 4.2 Mouth Bounding Box /// <summary> /// Draws rectangle around mouth region. /// </summary> public void DrawMouthBox(FaceLandmarks landmarks, Mat frame) { int boxWidth = 80; int boxHeight = 50; // Calculate center based on the vertical lip landmarks int centerX = (int)((landmarks.UpperLipTop.X + landmarks.UnderLipBottom.X) / 2); int centerY = (int)((landmarks.UpperLipTop.Y + landmarks.UnderLipBottom.Y) / 2); var mouthRect = new Rect(centerX - boxWidth / 2, centerY - boxHeight / 2, boxWidth, boxHeight); // Draw Mouth Box (Blue in BGR) Cv2.Rectangle(frame, mouthRect, new Scalar(255, 0, 0), 2); // Add Label Cv2.PutText(frame, "Mouth", new Point(mouthRect.X, mouthRect.Y - 5), HersheyFonts.HersheySimplex, 0.4, new Scalar(255, 0, 0), 1); } 4.3 Face Bounding Box /// <summary> /// Draws rectangle around entire face using the face rectangle from API. /// </summary> public void DrawFaceBox(FaceDetectionResult face, Mat frame) { var faceRect = face.FaceRectangle; if (faceRect == null) { return; } var rect = new Rect( faceRect.Left, faceRect.Top, faceRect.Width, faceRect.Height ); // Draw Face Bounding Box (Red in BGR) Cv2.Rectangle(frame, rect, new Scalar(0, 0, 255), 2); // Add Label with dimensions Cv2.PutText(frame, $"Face {faceRect.Width}x{faceRect.Height}", new Point(rect.X, rect.Y - 10), HersheyFonts.HersheySimplex, 0.5, new Scalar(0, 0, 255), 2); } 4.4 Nose Bounding Box /// <summary> /// Draws bounding box around nose using nose landmarks. /// </summary> public void DrawNoseBox(FaceLandmarks landmarks, Mat frame) { // Calculate horizontal bounds from Alar tips int minX = (int)Math.Min(landmarks.NoseLeftAlarOutTip.X, landmarks.NoseRightAlarOutTip.X); int maxX = (int)Math.Max(landmarks.NoseLeftAlarOutTip.X, landmarks.NoseRightAlarOutTip.X); // Calculate vertical bounds from Root to Tip int minY = (int)Math.Min(landmarks.NoseRootLeft.Y, landmarks.NoseTip.Y); int maxY = (int)landmarks.NoseTip.Y; // Create Rect with a 10px padding buffer var noseRect = new Rect( minX - 10, minY - 10, (maxX - minX) + 20, (maxY - minY) + 20 ); // Draw Nose Box (Yellow in BGR) Cv2.Rectangle(frame, noseRect, new Scalar(0, 255, 255), 2); } Part 5: Geometric Calculations with Landmarks 5.1 Calculating Euclidean Distance /// <summary> /// Calculates distance between two landmark points. /// </summary> public static double CalculateDistance(dynamic point1, dynamic point2) { double dx = point1.X - point2.X; double dy = point1.Y - point2.Y; return Math.Sqrt(dx * dx + dy * dy); } 5.2 Eye Aspect Ratio (EAR) Formula /// <summary> /// Calculates the Eye Aspect Ratio (EAR) to detect eye closure. /// </summary> public double CalculateEAR( FaceLandmarkCoordinate top1, FaceLandmarkCoordinate top2, FaceLandmarkCoordinate bottom1, FaceLandmarkCoordinate bottom2, FaceLandmarkCoordinate inner, FaceLandmarkCoordinate outer) { // Vertical distances double v1 = CalculateDistance(top1, bottom1); double v2 = CalculateDistance(top2, bottom2); // Horizontal distance double h = CalculateDistance(inner, outer); // EAR formula: (||p2-p6|| + ||p3-p5||) / (2 * ||p1-p4||) return (v1 + v2) / (2.0 * h); } Simplified Implementation: /// <summary> /// Calculates Eye Aspect Ratio (EAR) for a single eye. /// Reference: "Real-Time Eye Blink Detection using Facial Landmarks" (Soukupová & Čech, 2016) /// </summary> public double ComputeEAR(FaceLandmarks landmarks, bool isLeftEye) { var top = isLeftEye ? landmarks.EyeLeftTop : landmarks.EyeRightTop; var bottom = isLeftEye ? landmarks.EyeLeftBottom : landmarks.EyeRightBottom; var inner = isLeftEye ? landmarks.EyeLeftInner : landmarks.EyeRightInner; var outer = isLeftEye ? landmarks.EyeLeftOuter : landmarks.EyeRightOuter; if (top == null || bottom == null || inner == null || outer == null) { _logger.LogWarning("Missing eye landmarks"); return 1.0; // Return 1.0 (open) to prevent false positives for drowsiness } double verticalDist = CalculateDistance(top, bottom); double horizontalDist = CalculateDistance(inner, outer); // Simplified EAR for Azure 27-point model double ear = verticalDist / horizontalDist; _logger.LogDebug( "EAR for {Eye}: {Value:F3}", isLeftEye ? "left" : "right", ear ); return ear; } Usage Example: var leftEAR = ComputeEAR(landmarks, isLeftEye: true); var rightEAR = ComputeEAR(landmarks, isLeftEye: false); var avgEAR = (leftEAR + rightEAR) / 2.0; Console.WriteLine($"Average EAR: {avgEAR:F3}"); // Open eyes: ~0.25-0.30 // Closed eyes: ~0.10-0.15 5.3 Mouth Aspect Ratio (MAR) /// <summary> /// Calculates Mouth Aspect Ratio relative to face height. /// </summary> public double CalculateMouthAspectRatio(FaceLandmarks landmarks, FaceRectangle faceRect) { double mouthHeight = landmarks.UnderLipBottom.Y - landmarks.UpperLipTop.Y; double mouthWidth = CalculateDistance(landmarks.MouthLeft, landmarks.MouthRight); double mouthOpenRatio = mouthHeight / faceRect.Height; double mouthWidthRatio = mouthWidth / faceRect.Width; _logger.LogDebug( "Mouth - Height ratio: {HeightRatio:F3}, Width ratio: {WidthRatio:F3}", mouthOpenRatio, mouthWidthRatio ); return mouthOpenRatio; } 5.4 Inter-Eye Distance /// <summary> /// Calculates the distance between pupils (inter-pupillary distance). /// </summary> public double CalculateInterEyeDistance(FaceLandmarks landmarks) { return CalculateDistance(landmarks.PupilLeft, landmarks.PupilRight); } /// <summary> /// Calculates distance between inner eye corners. /// </summary> public double CalculateInnerEyeDistance(FaceLandmarks landmarks) { return CalculateDistance(landmarks.EyeLeftInner, landmarks.EyeRightInner); } 5.5 Face Symmetry Analysis /// <summary> /// Analyzes facial symmetry by comparing left and right sides. /// </summary> public FaceSymmetryMetrics AnalyzeFaceSymmetry(FaceLandmarks landmarks) { double centerX = landmarks.NoseTip.X; double leftEyeDistance = CalculateDistance(landmarks.EyeLeftInner, new { X = centerX, Y = landmarks.EyeLeftInner.Y }); double leftMouthDistance = CalculateDistance(landmarks.MouthLeft, new { X = centerX, Y = landmarks.MouthLeft.Y }); double rightEyeDistance = CalculateDistance(landmarks.EyeRightInner, new { X = centerX, Y = landmarks.EyeRightInner.Y }); double rightMouthDistance = CalculateDistance(landmarks.MouthRight, new { X = centerX, Y = landmarks.MouthRight.Y }); return new FaceSymmetryMetrics { EyeSymmetryRatio = leftEyeDistance / rightEyeDistance, MouthSymmetryRatio = leftMouthDistance / rightMouthDistance, IsSymmetric = Math.Abs(leftEyeDistance - rightEyeDistance) < 5.0 }; } public class FaceSymmetryMetrics { public double EyeSymmetryRatio { get; set; } public double MouthSymmetryRatio { get; set; } public bool IsSymmetric { get; set; } } Part 6: Head Pose Estimation 6.1 Understanding Head Pose Angles Azure Face API provides three Euler angles for head orientation: 6.2 Accessing Head Pose Data public void AnalyzeHeadPose(FaceDetectionResult face) { var headPose = face.FaceAttributes?.HeadPose; if (headPose == null) { _logger.LogWarning("Head pose not available"); return; } double yaw = headPose.Yaw; double pitch = headPose.Pitch; double roll = headPose.Roll; Console.WriteLine("Head Pose:"); Console.WriteLine($" Yaw: {yaw:F2}° (Left/Right)"); Console.WriteLine($" Pitch: {pitch:F2}° (Up/Down)"); Console.WriteLine($" Roll: {roll:F2}° (Tilt)"); InterpretHeadPose(yaw, pitch, roll); } 6.3 Interpreting Head Pose public string InterpretHeadPose(double yaw, double pitch, double roll) { var directions = new List<string>(); // Interpret Yaw (horizontal) if (Math.Abs(yaw) < 10) directions.Add("Looking Forward"); else if (yaw < -20) directions.Add($"Turned Left ({Math.Abs(yaw):F0}°)"); else if (yaw > 20) directions.Add($"Turned Right ({yaw:F0}°)"); // Interpret Pitch (vertical) if (Math.Abs(pitch) < 10) directions.Add("Level"); else if (pitch < -15) directions.Add($"Looking Down ({Math.Abs(pitch):F0}°)"); else if (pitch > 15) directions.Add($"Looking Up ({pitch:F0}°)"); // Interpret Roll (tilt) if (Math.Abs(roll) > 15) { string side = roll < 0 ? "Left" : "Right"; directions.Add($"Tilted {side} ({Math.Abs(roll):F0}°)"); } return string.Join(", ", directions); } 6.4 Visualizing Head Pose on Frame /// <summary> /// Draws head pose information with color-coded indicators. /// </summary> public void DrawHeadPoseInfo(Mat frame, HeadPose headPose, FaceRectangle faceRect) { double yaw = headPose.Yaw; double pitch = headPose.Pitch; double roll = headPose.Roll; int centerX = faceRect.Left + faceRect.Width / 2; int centerY = faceRect.Top + faceRect.Height / 2; string poseText = $"Yaw: {yaw:F1}° Pitch: {pitch:F1}° Roll: {roll:F1}°"; Cv2.PutText(frame, poseText, new Point(faceRect.Left, faceRect.Top - 10), HersheyFonts.HersheySimplex, 0.5, new Scalar(255, 255, 255), 1); int arrowLength = 50; double yawRadians = yaw * Math.PI / 180.0; int arrowEndX = centerX + (int)(arrowLength * Math.Sin(yawRadians)); Cv2.ArrowedLine(frame, new Point(centerX, centerY), new Point(arrowEndX, centerY), new Scalar(0, 255, 0), 2, tipLength: 0.3); double pitchRadians = -pitch * Math.PI / 180.0; int arrowPitchEndY = centerY + (int)(arrowLength * Math.Sin(pitchRadians)); Cv2.ArrowedLine(frame, new Point(centerX, centerY), new Point(centerX, arrowPitchEndY), new Scalar(255, 0, 0), 2, tipLength: 0.3); } 6.5 Detecting Head Orientation States public enum HeadOrientation { Forward, Left, Right, Up, Down, TiltedLeft, TiltedRight, UpLeft, UpRight, DownLeft, DownRight } public List<HeadOrientation> DetectHeadOrientation(HeadPose headPose) { const double THRESHOLD = 15.0; bool lookingUp = headPose.Pitch > THRESHOLD; bool lookingDown = headPose.Pitch < -THRESHOLD; bool lookingLeft = headPose.Yaw < -THRESHOLD; bool lookingRight = headPose.Yaw > THRESHOLD; var orientations = new List<HeadOrientation>(); if (!lookingUp && !lookingDown && !lookingLeft && !lookingRight) orientations.Add(HeadOrientation.Forward); if (lookingUp && !lookingLeft && !lookingRight) orientations.Add(HeadOrientation.Up); if (lookingDown && !lookingLeft && !lookingRight) orientations.Add(HeadOrientation.Down); if (lookingLeft && !lookingUp && !lookingDown) orientations.Add(HeadOrientation.Left); if (lookingRight && !lookingUp && !lookingDown) orientations.Add(HeadOrientation.Right); if (lookingUp && lookingLeft) orientations.Add(HeadOrientation.UpLeft); if (lookingUp && lookingRight) orientations.Add(HeadOrientation.UpRight); if (lookingDown && lookingLeft) orientations.Add(HeadOrientation.DownLeft); if (lookingDown && lookingRight) orientations.Add(HeadOrientation.DownRight); return orientations; } Part 7: Real-Time Video Processing 7.1 Setting Up Video Capture using OpenCvSharp; public class RealTimeFaceAnalyzer : IDisposable { private VideoCapture? _capture; private Mat? _frame; private readonly FaceClient _faceClient; private bool _isRunning; public async Task StartAsync() { _capture = new VideoCapture(0); _frame = new Mat(); _isRunning = true; await Task.Run(() => ProcessVideoLoop()); } private async Task ProcessVideoLoop() { while (_isRunning) { if (_capture == null || !_capture.IsOpened()) break; _capture.Read(_frame); if (_frame == null || _frame.Empty()) { await Task.Delay(1); // Minimal delay to prevent CPU spiking continue; } Cv2.Resize(_frame, _frame, new Size(640, 480)); // Ensure we don't await indefinitely in the rendering loop _ = ProcessFrameAsync(_frame.Clone()); Cv2.ImShow("Face Analysis", _frame); if (Cv2.WaitKey(30) == 'q') break; } Dispose(); } private async Task ProcessFrameAsync(Mat frame) { // This is where your DrawFaceBox, DrawAllLandmarks, and EAR logic will sit. // Remember to use try-catch here to prevent API errors from crashing the loop. } public void Dispose() { _isRunning = false; _capture?.Dispose(); _frame?.Dispose(); Cv2.DestroyAllWindows(); } } 7.2 Optimizing API Calls Problem: Calling Azure Face API on every frame (30 fps) is expensive and slow. Solution: Call API once per second, cache results for 30 frames. private List<FaceDetectionResult> _cachedFaces = new(); private DateTime _lastDetectionTime = DateTime.MinValue; private readonly object _cacheLock = new(); private async Task ProcessFrameAsync(Mat frame) { if ((DateTime.Now - _lastDetectionTime).TotalSeconds >= 1.0) { _lastDetectionTime = DateTime.Now; byte[] imageBytes; Cv2.ImEncode(".jpg", frame, out imageBytes); var faces = await DetectFacesAsync(imageBytes); lock (_cacheLock) { _cachedFaces = faces; } } List<FaceDetectionResult> facesToProcess; lock (_cacheLock) { facesToProcess = _cachedFaces.ToList(); } foreach (var face in facesToProcess) { DrawFaceAnnotations(face, frame); } } Performance Improvement: 30x fewer API calls (1/sec instead of 30/sec) ~$0.02/hour instead of ~$0.60/hour Smooth 30 fps rendering < 100ms latency for visual updates 7.3 Drawing Complete Face Annotations private void DrawFaceAnnotations(FaceDetectionResult face, Mat frame) { DrawFaceBox(face, frame); if (face.FaceLandmarks != null) { DrawAllLandmarks(face.FaceLandmarks, frame); DrawEyeBoxes(face.FaceLandmarks, frame); DrawMouthBox(face.FaceLandmarks, frame); DrawNoseBox(face.FaceLandmarks, frame); double leftEAR = ComputeEAR(face.FaceLandmarks, isLeftEye: true); double rightEAR = ComputeEAR(face.FaceLandmarks, isLeftEye: false); double avgEAR = (leftEAR + rightEAR) / 2.0; Cv2.PutText(frame, $"EAR: {avgEAR:F3}", new Point(10, 30), HersheyFonts.HersheySimplex, 0.6, new Scalar(0, 255, 0), 2); } if (face.FaceAttributes?.HeadPose != null) { DrawHeadPoseInfo(frame, face.FaceAttributes.HeadPose, face.FaceRectangle); string orientation = InterpretHeadPose(face.FaceAttributes.HeadPose.Yaw, face.FaceAttributes.HeadPose.Pitch, face.FaceAttributes.HeadPose.Roll); Cv2.PutText(frame, orientation, new Point(10, 60), HersheyFonts.HersheySimplex, 0.6, new Scalar(255, 255, 0), 2); } } Part 8: Advanced Features and Use Cases 8.1 Face Tracking Across Frames public class FaceTracker { private class TrackedFace { public FaceRectangle Rectangle { get; set; } public DateTime LastSeen { get; set; } public int TrackId { get; set; } } private List<TrackedFace> _trackedFaces = new(); private int _nextTrackId = 1; public int TrackFace(FaceRectangle newFace) { const int MATCH_THRESHOLD = 50; var match = _trackedFaces.FirstOrDefault(tf => { double distance = Math.Sqrt(Math.Pow(tf.Rectangle.Left - newFace.Left, 2) + Math.Pow(tf.Rectangle.Top - newFace.Top, 2)); return distance < MATCH_THRESHOLD; }); if (match != null) { match.Rectangle = newFace; match.LastSeen = DateTime.Now; return match.TrackId; } var newTrack = new TrackedFace { Rectangle = newFace, LastSeen = DateTime.Now, TrackId = _nextTrackId++ }; _trackedFaces.Add(newTrack); return newTrack.TrackId; } public void RemoveOldTracks(TimeSpan maxAge) { _trackedFaces.RemoveAll(tf => DateTime.Now - tf.LastSeen > maxAge); } } 8.2 Multi-Face Detection and Analysis public async Task<FaceAnalysisReport> AnalyzeMultipleFacesAsync(byte[] imageBytes) { var faces = await DetectFacesAsync(imageBytes); var report = new FaceAnalysisReport { TotalFacesDetected = faces.Count, Timestamp = DateTime.Now, Faces = new List<SingleFaceAnalysis>() }; for (int i = 0; i < faces.Count; i++) { var face = faces[i]; var analysis = new SingleFaceAnalysis { FaceIndex = i, FaceLocation = face.FaceRectangle, FaceSize = face.FaceRectangle.Width * face.FaceRectangle.Height }; if (face.FaceLandmarks != null) { analysis.LeftEyeEAR = ComputeEAR(face.FaceLandmarks, true); analysis.RightEyeEAR = ComputeEAR(face.FaceLandmarks, false); analysis.InterPupillaryDistance = CalculateInterEyeDistance(face.FaceLandmarks); } if (face.FaceAttributes?.HeadPose != null) { analysis.HeadYaw = face.FaceAttributes.HeadPose.Yaw; analysis.HeadPitch = face.FaceAttributes.HeadPose.Pitch; analysis.HeadRoll = face.FaceAttributes.HeadPose.Roll; } report.Faces.Add(analysis); } report.Faces = report.Faces.OrderByDescending(f => f.FaceSize).ToList(); return report; } public class FaceAnalysisReport { public int TotalFacesDetected { get; set; } public DateTime Timestamp { get; set; } public List<SingleFaceAnalysis> Faces { get; set; } } public class SingleFaceAnalysis { public int FaceIndex { get; set; } public FaceRectangle FaceLocation { get; set; } public int FaceSize { get; set; } public double LeftEyeEAR { get; set; } public double RightEyeEAR { get; set; } public double InterPupillaryDistance { get; set; } public double HeadYaw { get; set; } public double HeadPitch { get; set; } public double HeadRoll { get; set; } } 8.3 Exporting Landmark Data to JSON using System.Text.Json; public string ExportLandmarksToJson(FaceDetectionResult face) { var landmarks = face.FaceLandmarks; var landmarkData = new { Face = new { Rectangle = new { face.FaceRectangle.Left, face.FaceRectangle.Top, face.FaceRectangle.Width, face.FaceRectangle.Height } }, Eyes = new { Left = new { Outer = new { landmarks.EyeLeftOuter.X, landmarks.EyeLeftOuter.Y }, Inner = new { landmarks.EyeLeftInner.X, landmarks.EyeLeftInner.Y }, Top = new { landmarks.EyeLeftTop.X, landmarks.EyeLeftTop.Y }, Bottom = new { landmarks.EyeLeftBottom.X, landmarks.EyeLeftBottom.Y } }, Right = new { Outer = new { landmarks.EyeRightOuter.X, landmarks.EyeRightOuter.Y }, Inner = new { landmarks.EyeRightInner.X, landmarks.EyeRightInner.Y }, Top = new { landmarks.EyeRightTop.X, landmarks.EyeRightTop.Y }, Bottom = new { landmarks.EyeRightBottom.X, landmarks.EyeRightBottom.Y } } }, Mouth = new { UpperLipTop = new { landmarks.UpperLipTop.X, landmarks.UpperLipTop.Y }, UnderLipBottom = new { landmarks.UnderLipBottom.X, landmarks.UnderLipBottom.Y }, Left = new { landmarks.MouthLeft.X, landmarks.MouthLeft.Y }, Right = new { landmarks.MouthRight.X, landmarks.MouthRight.Y } }, Nose = new { Tip = new { landmarks.NoseTip.X, landmarks.NoseTip.Y }, RootLeft = new { landmarks.NoseRootLeft.X, landmarks.NoseRootLeft.Y }, RootRight = new { landmarks.NoseRootRight.X, landmarks.NoseRootRight.Y } }, HeadPose = face.FaceAttributes?.HeadPose != null ? new { face.FaceAttributes.HeadPose.Yaw, face.FaceAttributes.HeadPose.Pitch, face.FaceAttributes.HeadPose.Roll } : null }; return JsonSerializer.Serialize(landmarkData, new JsonSerializerOptions { WriteIndented = true }); } Part 9: Practical Applications 9.1 Gaze Direction Estimation public enum GazeDirection { Center, Left, Right, Up, Down, UpLeft, UpRight, DownLeft, DownRight } public GazeDirection EstimateGazeDirection(HeadPose headPose) { const double THRESHOLD = 15.0; bool lookingUp = headPose.Pitch > THRESHOLD; bool lookingDown = headPose.Pitch < -THRESHOLD; bool lookingLeft = headPose.Yaw < -THRESHOLD; bool lookingRight = headPose.Yaw > THRESHOLD; if (lookingUp && lookingLeft) return GazeDirection.UpLeft; if (lookingUp && lookingRight) return GazeDirection.UpRight; if (lookingDown && lookingLeft) return GazeDirection.DownLeft; if (lookingDown && lookingRight) return GazeDirection.DownRight; if (lookingUp) return GazeDirection.Up; if (lookingDown) return GazeDirection.Down; if (lookingLeft) return GazeDirection.Left; if (lookingRight) return GazeDirection.Right; return GazeDirection.Center; } 9.2 Expression Analysis Using Landmarks public class ExpressionAnalyzer { public bool IsSmiling(FaceLandmarks landmarks) { double mouthCenterY = (landmarks.UpperLipTop.Y + landmarks.UnderLipBottom.Y) / 2; double leftCornerY = landmarks.MouthLeft.Y; double rightCornerY = landmarks.MouthRight.Y; return leftCornerY < mouthCenterY && rightCornerY < mouthCenterY; } public bool IsMouthOpen(FaceLandmarks landmarks, FaceRectangle faceRect) { double mouthHeight = landmarks.UnderLipBottom.Y - landmarks.UpperLipTop.Y; double mouthOpenRatio = mouthHeight / faceRect.Height; return mouthOpenRatio > 0.08; // 8% of face height } public bool AreEyesClosed(FaceLandmarks landmarks) { double leftEAR = ComputeEAR(landmarks, isLeftEye: true); double rightEAR = ComputeEAR(landmarks, isLeftEye: false); double avgEAR = (leftEAR + rightEAR) / 2.0; return avgEAR < 0.18; // Threshold for closed eyes } } 9.3 Face Orientation for AR/VR Applications public class FaceOrientationFor3D { public (Vector3 forward, Vector3 up, Vector3 right) GetFaceOrientation(HeadPose headPose) { double yawRad = headPose.Yaw * Math.PI / 180.0; double pitchRad = headPose.Pitch * Math.PI / 180.0; double rollRad = headPose.Roll * Math.PI / 180.0; var forward = new Vector3((float)(Math.Sin(yawRad) * Math.Cos(pitchRad)), (float)(-Math.Sin(pitchRad)), (float)(Math.Cos(yawRad) * Math.Cos(pitchRad))); var up = new Vector3((float)(Math.Sin(yawRad) * Math.Sin(pitchRad) * Math.Cos(rollRad) - Math.Cos(yawRad) * Math.Sin(rollRad)), (float)(Math.Cos(pitchRad) * Math.Cos(rollRad)), (float)(Math.Cos(yawRad) * Math.Sin(pitchRad) * Math.Cos(rollRad) + Math.Sin(yawRad) * Math.Sin(rollRad))); var right = Vector3.Cross(up, forward); return (forward, up, right); } } public struct Vector3 { public float X, Y, Z; public Vector3(float x, float y, float z) { X = x; Y = y; Z = z; } public static Vector3 Cross(Vector3 a, Vector3 b) => new Vector3(a.Y * b.Z - a.Z * b.Y, a.Z * b.X - a.X * b.Z, a.X * b.Y - a.Y * b.X); } Conclusion This technical guide has explored the capabilities of Azure Face API for facial analysis in C#. We've covered: Key Capabilities Demonstrated Facial Landmark Detection - Accessing 27 precise points on the face Head Pose Estimation - Tracking yaw, pitch, and roll angles Geometric Calculations - Computing EAR, distances, and ratios Visual Annotations - Drawing bounding boxes with OpenCV Real-Time Processing - Optimized video stream analysis Technical Achievements Computer Vision Math: Euclidean distance calculations Eye Aspect Ratio (EAR) formula Mouth aspect ratio measurements Face symmetry analysis OpenCV Integration: Drawing bounding boxes and landmarks Color-coded feature highlighting Real-time annotation overlays Video capture and processing Practical Applications This technology enables: 👁️ Gaze tracking for UI/UX studies 🎮 Head-controlled game interfaces 📸 Auto-focus camera systems 🎭 Expression analysis for feedback 🥽 AR/VR avatar control 📊 Attention analytics for presentations ♿ Accessibility features for disabled users Performance Metrics Detection Accuracy: 95%+ for frontal faces Landmark Precision: ±2-3 pixels Processing Latency: 200-500ms per API call Frame Rate: 30 fps with caching Further Exploration Advanced Topics to Explore: Face Recognition - Identify individuals Age/Gender Detection - Demographic analysis Emotion Detection - Facial expression classification Face Verification - 1:1 identity confirmation Similar Face Search - 1:N face matching Face Grouping - Cluster similar faces Call to Action 📌 Explore these resources to get started: Official Documentation Azure Face API Documentation Face API REST Reference Azure Face SDK for .NET Related Libraries OpenCVSharp - OpenCV wrapper for .NET System.Drawing - .NET image processing Source Code GitHub Repository: ravimodi_microsoft/SmartDriver Sample Code: Included in this articleNew Azure Open AI models bring fast, expressive, and real‑time AI experiences in Microsoft Foundry
Modern AI applications, whether voice‑first experiences or building large software systems, rarely fit into a single prompt. Real work unfolds over time: maintaining context, following instructions, invoking tools, and adapting as requirements evolve. When these foundations break down through latency spikes, instruction drift, or unreliable tool calls, both user conversations and developer workflows are impacted. OpenAI’s latest models address this shared challenge by prioritizing continuity and reliability across real‑time interaction and long‑running engineering tasks. Starting today, GPT-Realtime-1.5, GPT-Audio-1.5, and GPT-5.3-Codex are rolling out into Microsoft Foundry. Together, these models reflect the growing needs of the modern developer and push the needle from short, stateless interactions toward AI systems that can reason, act, and collaborate over time. GPT-5.3-Codex at a glance GPT‑5.3‑Codex brings together advanced coding capability with broader reasoning and professional problem solving in a single model built for real engineering work. It unifies the frontier coding performance of GPT-5.2-Codex with the reasoning and professional knowledge capabilities of GPT5.2 in one system. This shifts the experience from optimizing isolated outputs to supporting longer running development efforts; where repositories are large, changes span multiple steps, and requirements aren’t always fully specified at the start. What’s improved Model experiences 25% faster execution time, according to Open AI, than its predecessors so developers can accelerate development of new applications. Built for long-running tasks that involve research, tool use, and complex, multi‑step execution while maintaining context. Midtask steerability and frequent updates allow developers to redirect and collaborate with the model as it works without losing context. Stronger computer-use capabilities allow developers to execute across the full spectrum of technical work. Common use cases Developers and teams can apply GPT‑5.3‑Codex across a wide range of scenarios, including: Refactoring and modernizing large or legacy applications Performing multi‑step migrations or upgrades Running agentic developer workflows that span analysis, implementation, testing, and remediation Automating code reviews, test generation, and defect detection Supporting development in security‑sensitive or regulated environments Pricing Model Input Price/1M Tokens Cached Input Price/1M Tokens Output Price/1M Tokens GPT-5.3-Codex $1.75 $0.175 $14.00 GPT-Realtime-1.5 and GPT-Audio-1.5 at a glance The models deliver measurable gains in reasoning and speech understanding for real‑time voice interactions on Microsoft Foundry. In OpenAI’s evaluations, it shows a +5% lift on Big Bench Audio (reasoning), a +10.23% improvement in alphanumeric transcription, and a +7% gain in instruction following, while maintaining low‑latency performance. Key improvements include: What's improved More natural‑sounding speech: Audio output is smoother and more conversational, with improved pacing and prosody. Higher audio quality: Clearer, more consistent audio output across supported voices. Improved instruction following: Better alignment with developer‑provided system and user instructions during live interactions. Function calling support: Enables structured, tool‑driven interactions within real‑time audio flows. Common use cases Developers are using GPT-Realtime-1.5 and GPT-Audio-1.5 for scenarios where low‑latency voice interaction is essential, including: Conversational voice agents for customer support or internal help desks Voice‑enabled assistants embedded in applications or devices Live voice interfaces for kiosks, demos, and interactive experiences Hands‑free workflows where audio input and output replace keyboard interaction Pricing Model Text Audio Image Input Cached Input Output Input Cached Input Output Input Cached Input Output GPT-Realtime-1.5 $4.00 $0.04 $16.0 $32.0 $0.40 $64.00 $4.00 $0.04 $16.0 GPT-Audio-1.5 $2.50 n/a $10.0 $32.00 n/a $64.00 $2.50 n/a $10.0 Getting started in Microsoft Foundry Start building in Microsoft Foundry, evaluate performance, and explore Azure Open AI models today. Foundry brings evaluation, deployment, and governance into a single workflow, helping teams progress from experiments to scalable applications while maintaining security and operational controls.Visualize Workflows and Architecture with Mermaid Charts in Visual Studio 2026
Modern software systems are more complex than ever. Microservices talk to APIs. Background workers process queues. Frontend apps interact with authentication layers, caching services, and databases. In the middle of all this complexity, one thing becomes absolutely critical: clear visualization. With Visual Studio 2026, developers no longer need third-party plugins to visualize workflows and architecture. Visual Studio 2026 renders Mermaid charts directly in the editor — no extensions required. You can write Mermaid syntax yourself or let GitHub Copilot generate it for you. Flowcharts, sequence diagrams, and other visualizations render inline, keeping documentation inside your development workflow. This is more than just a convenience feature. It’s a shift in how developers document, collaborate, and communicate system design. https://dellenny.com/visualize-workflows-and-architecture-with-mermaid-charts-in-visual-studio-2026/Implementing A2A protocol in NET: A Practical Guide
As AI systems mature into multi‑agent ecosystems, the need for agents to communicate reliably and securely has become fundamental. Traditionally, agents built on different frameworks like Semantic Kernel, LangChain, custom orchestrators, or enterprise APIs do not share a common communication model. This creates brittle integrations, duplicate logic, and siloed intelligence. The Agent‑to‑Agent Standard (A2AS) addresses this gap by defining a universal, vendor‑neutral protocol for structured agent interoperability. A2A establishes a common language for agents, built on familiar web primitives: JSON‑RPC 2.0 for messaging and HTTPS for transport. Each agent exposes a machine‑readable Agent Card describing its capabilities, supported input/output modes, and authentication requirements. Interactions are modeled as Tasks, which support synchronous, streaming, and long‑running workflows. Messages exchanged within a task contain Parts; text, structured data, files, or streams, that allow agents to collaborate without exposing internal implementation details. By standardizing discovery, communication, authentication, and task orchestration, A2A enables organizations to build composable AI architectures. Specialized agents can coordinate deep reasoning, planning, data retrieval, or business automation regardless of their underlying frameworks or hosting environments. This modularity, combined with industry adoption and Linux Foundation governance, positions A2A as a foundational protocol for interoperable AI systems. A2AS in .NET — Implementation Guide Prerequisites • .NET 8 SDK • Visual Studio 2022 (17.8+) • A2A and A2A.AspNetCore packages • Curl/Postman (optional, for direct endpoint testing) The open‑source A2A project provides a full‑featured .NET SDK, enabling developers to build and host A2A agents using ASP.NET Core or integrate with other agents as a client. Two A2A and A2A.AspNetCore packages power the experience. The SDK offers: A2AClient - to call remote agents TaskManager - to manage incoming tasks & message routing AgentCard / Message / Task models - strongly typed protocol objects MapA2A() - ASP.NET Core router integration that auto‑generates protocol endpoints This allows you to expose an A2A‑compliant agent with minimal boilerplate. Project Setup Create two separate projects: CurrencyAgentService → ASP.NET Core web project that hosts the agent A2AClient → Console app that discovers the agent card and sends a message Install the packages from the pre-requisites in the above projects. Building a Simple A2A Agent (Currency Agent Example) Below is a minimal Currency Agent implemented in ASP.NET Core. It responds by converting amounts between currencies. Step 1: In CurrencyAgentService project, create the CurrencyAgentImplementation class to implement the A2A agent. The class contains the logic for the following: a) Describing itself (agent “card” metadata). b) Processing the incoming text messages like “100 USD to EUR”. c) Returning a single text response with the conversion. The AttachTo(ITaskManager taskManager) method hooks two delegates on the provided taskManager - a) OnAgentCardQuery → GetAgentCardAsync: returns agent metadata. b) OnMessageReceived → ProcessMessageAsync: handles incoming messages and produces a response. Step 2: In the Program.cs of the Currency Agent Solution, create a TaskManager , and attach the agent to it, and expose the A2A endpoint. Typical flow: GET /agent → A2A host asks OnAgentCardQuery → returns the card POST /agent with a text message → A2A host calls OnMessageReceived → returns the conversion text. All fully A2A‑compliant. Calling an A2A Agent from .NET To interact with any A2A‑compliant agent from .NET, the client follows a predictable sequence: identify where the agent lives, discover its capabilities through the Agent Card, initialize a correctly configured A2AClient, construct a well‑formed message, send it asynchronously, and finally interpret the structured response. This ensures your client is fully aligned with the agent’s advertised contract and remains resilient as capabilities evolve. Below are the steps implemented to call the A2A agent from the A2A client: Identify the agent endpoint: Why: You need a stable base URL to resolve the agent’s metadata and send messages. What: Construct a Uri pointing to the agent service, e.g., https://localhost:7009/agent. Discover agent capabilities via an Agent Card. Why: Agent Cards provide a contract: name, description, final URL to call, and features (like streaming). This de-couples your client from hard-coded assumptions and enables dynamic capability checks. What: Use A2ACardResolver with the endpoint Uri, then call GetAgentCardAsync() to obtain an AgentCard. Initialize the A2AClient with the resolved URL. Why: The client encapsulates transport details and ensures messages are sent to the correct agent endpoint, which may differ from the discovery URL. What: Create A2AClient using new Uri (currencyCard.Url) from the Agent Card for correctness. Construct a well-formed agent request message. Why: Agents typically require structured messages for roles, traceability, and multi-part inputs. A unique message ID supports deduplication and logging. What: Build an AgentMessage: • Role = MessageRole.User clarifies intent. • MessageId = Guid.NewGuid().ToString() ensures uniqueness. • Parts contains content; for simple queries, a single TextPart with the prompt (e.g., “100 USD to EUR”). Package and send the message. Why: MessageSendParams can carry the message plus any optional settings (e.g., streaming flags or context). Using a dedicated params object keeps the API extensible. What: Wrap the AgentMessage in MessageSendParams and call SendMessageAsync(...) on the A2AClient. Outcome: Await the asynchronous response to avoid blocking and to stay scalable. Interpret the agent response. Why: Agents can return multiple Parts (text, data, attachments). Extracting the appropriate part avoids assumptions and keeps your client robust. What: Cast to AgentMessage, then read the first TextPart’s Text for the conversion result in this scenario. Best Practices 1. Keep Agents Focused and Single‑Purpose Design each agent around a clear, narrow capability (e.g., currency conversion, scheduling, document summarization). Single‑responsibility agents are easier to reason about, scale, and test, especially when they become part of larger multi‑agent workflows. 2. Maintain Accurate and Helpful Agent Cards The Agent Card is the first interaction point for any client. Ensure it accurately reflects: Supported input/output formats Streaming capabilities Authentication requirements (if any) Version information A clean and honest card helps clients integrate reliably without guesswork. 3. Prefer Structured Inputs and Outputs Although A2A supports plain text, using structured payloads through DataPart objects significantly improves consistency. JSON inputs and outputs reduce ambiguity, eliminate prompt‑engineering edge cases, and make agent behavior more deterministic especially when interacting with other automated agents. 4. Use Meaningful Task States Treat A2A Tasks as proper state machines. Transition through states intentionally (Submitted → Working → Completed, or Working → InputRequired → Completed). This gives clients clarity on progress, makes long‑running operations manageable, and enables more sophisticated control flows. 5. Provide Helpful Error Messages Make use of A2A and JSON‑RPC error codes such as -32602 (invalid input) or -32603 (internal error), and include additional context in the error payload. Avoid opaque messages, error details should guide the client toward recovery or correction. 6. Keep Agents Stateless Where Possible Stateless agents are easier to scale and less prone to hidden failures. When state is necessary, ensure it is stored externally or passed through messages or task contexts. For local POCs, in‑memory state is acceptable, but design with future statelessness in mind. 7. Validate Input Strictly Do not assume incoming messages are well‑formed. Validate fields, formats, and required parameters before processing. For example, a currency conversion agent should confirm both currencies exist and the value is numeric before attempting a conversion. 8. Design for Streaming Even if Disabled Streaming is optional, but it’s a powerful pattern for agents that perform progressive reasoning or long computations. Structuring your logic so it can later emit partial TextPart updates makes it easy to upgrade from synchronous to streaming workflows. 9. Include Traceability Metadata Embed and log identifiers such as TaskId, MessageId, and timestamps. These become crucial for debugging multi‑agent scenarios, improving observability, and correlating distributed workflows—especially once multiple agents collaborate. 10. Offer Clear Guidance When Input Is Missing Instead of returning a generic failure, consider shifting the task to InputRequired and explaining what the client should provide. This improves usability and makes your agent self‑documenting for new consumers.Open AI’s GPT-5.1-codex-max in Microsoft Foundry: Igniting a New Era for Enterprise Developers
Announcing GPT-5.1-codex-max: The Future of Enterprise Coding Starts Now We’re thrilled to announce the general availability of OpenAI's GPT-5.1-codex-max in Microsoft Foundry Models; a leap forward that redefines what’s possible for enterprise-grade coding agents. This isn’t just another model release; it’s a celebration of innovation, partnership, and the relentless pursuit of developer empowerment. At Microsoft Ignite, we unveiled Microsoft Foundry: a unified platform where businesses can confidently choose the right model for every job, backed by enterprise-grade reliability. Foundry brings together the best from OpenAI, Anthropic, xAI, Black Forest Labs, Cohere, Meta, Mistral, and Microsoft’s own breakthroughs, all under one roof. Our partnership with Anthropic is a testament to our commitment to giving developers access to the most advanced, safe, and high-performing models in the industry. And now, with GPT-5.1-codex-max joining the Foundry family, the possibilities for intelligent applications and agentic workflows have never been greater. GPT 5.1-codex-max is available today in Microsoft Foundry and accessible in Visual Studio Code via the Foundry extension . Meet GPT-5.1-codex-max: Enterprise-Grade Coding Agent for Complex Projects GPT-5.1-codex-max is engineered for those who build the future. Imagine tackling complex, long-running projects without losing context or momentum. GPT-5.1-codex-max delivers efficiency at scale, cross-platform readiness, and proven performance with top scores on SWE-Bench (77.9), the gold standard for AI coding. With GPT-5.1-codex-max, developers can focus on creativity and problem-solving, while the model handles the heavy lifting. GPT-5.1-codex-max isn’t just powerful; it’s practical, designed to solve real challenges for enterprise developers: Multi-Agent Coding Workflows: Automate repetitive tasks across microservices, maintaining shared context for seamless collaboration. Enterprise App Modernization: Effortlessly refactor legacy .NET and Java applications into cloud-native architectures. Secure API Development: Generate and validate secure API endpoints, with `compliance checks built-in for peace of mind. Continuous Integration Support: Integrate GPT-5.1-codex-max into CI/CD pipelines for automated code reviews and test generation, accelerating delivery cycles. These use cases are just the beginning. GPT-5.1-codex-max is your partner in building robust, scalable, and secure solutions. Foundry: Platform Built for Developers Who Build the Future Foundry is more than a model catalog—it’s an enterprise AI platform designed for developers who need choice, reliability, and speed. • Choice Without Compromise: Access the widest range of models, including frontier models from leading model providers. • Enterprise-Grade Infrastructure: Built-in security, observability, and governance for responsible AI at scale. • Integrated Developer Experience: From GitHub to Visual Studio Code, Foundry connects with tools developers love for a frictionless build-to-deploy journey. Start Building Smarter with GPT-5.1-codex-max in Foundry The future is here, and it’s yours to shape. Supercharge your coding workflows with GPT-5.1-codex-max in Microsoft Foundry today. Learn more about Microsoft Foundry: aka.ms/IgniteFoundryModels. Watch Ignite sessions for deep dives and demos: ignite.microsoft.com. Build faster, smarter, and with confidence on the platform redefining enterprise AI.Unlocking AI-Driven Data Access: Azure Database for MySQL Support via the Azure MCP Server
Step into a new era of data-driven intelligence with the fusion of Azure MCP Server and Azure Database for MySQL, where your MySQL data is no longer just stored, but instantly conversational, intelligent and action-ready. By harnessing the open-standard Model Context Protocol (MCP), your AI agents can now query, analyze and automate in natural language, accessing tables, surfacing insights and acting on your MySQL-driven business logic as easily as chatting with a colleague. It’s like giving your data a voice and your applications a brain, all within Azure’s trusted cloud platform. We are excited to announce that we have added support for Azure Database for MySQL in Azure MCP Server. The Azure MCP Server leverages the Model Context Protocol (MCP) to allow AI agents to seamlessly interact with various Azure services to perform context-aware operations such as querying databases and managing cloud resources. Building on this foundation, the Azure MCP Server now offers a set of tools that AI agents and apps can invoke to interact with Azure Database for MySQL - enabling them to list and query databases, retrieve schema details of tables, and access server configurations and parameters. These capabilities are delivered through the same standardized interface used for other Azure services, making it easier to the adopt the MCP standard for leveraging AI to work with your business data and operations across the Azure ecosystem. Before we delve into these new tools and explore how to get started with them, let’s take a moment to refresh our understanding of MCP and the Azure MCP Server - what they are, how they work, and why they matter. MCP architecture and key components The Model Context Protocol (MCP) is an emerging open protocol designed to integrate AI models with external data sources and services in a scalable, standardized, and secure manner. MCP dictates a client-server architecture with four key components: MCP Host, MCP Client, MCP Server and external data sources, services and APIs that provide the data context required to enhance AI models. To explain briefly, an MCP Host (AI apps and agents) includes an MCP client component that connects to one or more MCP Servers. These servers are lightweight programs that securely interface with external data sources, services and APIs and exposes them to MCP clients in the form of standardized capabilities called tools, resources and prompts. Learn more: MCP Documentation What is Azure MCP Server? Azure offers a multitude of cloud services that help developers build robust applications and AI solutions to address business needs. The Azure MCP Server aims to expose these powerful services for agentic usage, allowing AI systems to perform operations that are context-aware of your Azure resources and your business data within them, while ensuring adherence to the Model Context Protocol. It supports a wide range of Azure services and tools including Azure AI Search, Azure Cosmos DB, Azure Storage, Azure Monitor, Azure CLI and Developer CLI extensions. This means that you can empower AI agents, apps and tools to: Explore your Azure resources, such as listing and retrieving details on your Azure subscriptions, resource groups, services, databases, and tables. Search, query and analyze your data and logs. Execute CLI and Azure Developer CLI commands directly, and more! Learn more: Azure MCP Server GitHub Repository Introducing new Azure MCP Server tools to interact with Azure Database for MySQL The Azure MCP Server now includes the following tools that allow AI agents to interact with Azure Database for MySQL and your valuable business data residing in these servers, in accordance with the MCP standard: Tool Description Example Prompts azmcp_mysql_server_list List all MySQL servers in a subscription & resource group "List MySQL servers in resource group 'prod-rg'." "Show MySQL servers in region 'eastus'." azmcp_mysql_server_config_get Retrieve the configuration of a MySQL server "What is the backup retention period for server 'my-mysql-server'?" "Show storage allocation for server 'my-mysql-server'." azmcp_mysql_server_param_get Retrieve a specific parameter of a MySQL server "Is slow_query_log enabled on server my-mysql-server?" "Get innodb_buffer_pool_size for server my-mysql-server." azmcp_mysql_server_param_set Set a specific parameter of a MySQL server to a specific value "Set max_connections to 500 on server my-mysql-server." "Set wait_timeout to 300 on server my-mysql-server." azmcp_mysql_table_list List all tables in a MySQL database "List tables starting with 'tmp_' in database 'appdb'." "How many tables are in database 'analytics'?" azmcp_mysql_table_schema_get Get the schema of a specific table in a MySQL database "Show indexes for table 'transactions' in database 'billing'." "What is the primary key for table 'users' in database 'auth'?" azmcp_mysql_database_query Executes a SELECT query on a MySQL Database. The query must start with SELECT and cannot contain any destructive SQL operations for security reasons. “How many orders were placed in the last 30 days in the salesdb.orders table?” “Show the number of new users signed up in the last week in appdb.users grouped by day.” These interactions are secured using Microsoft Entra authentication, which enables seamless, identity-based access to Azure Database for MySQL - eliminating the need for password storage and enhancing overall security. How are these new tools in the Azure MCP Server different from the standalone MCP Server for Azure Database for MySQL? We have integrated the key capabilities of the Azure Database for MySQL MCP server into the Azure MCP Server, making it easier to connect your agentic apps not only to Azure Database for MySQL but also to other Azure services through one unified and secure interface! How to get started Installing and running the Azure MCP Server is quick and easy! Use GitHub Copilot in Visual Studio Code to gain meaningful insights from your business data in Azure Database for MySQL. Pre-requisites Install Visual Studio Code. Install GitHub Copilot and GitHub Copilot Chat extensions. An Azure Database for MySQL with Microsoft Entra authentication enabled. Ensure that the MCP Server is installed on a system with network connectivity and credentials to connect to Azure Database for MySQL. Installation and Testing Please use this guide for installation: Azure MCP Server Installation Guide Try the following prompts with your Azure Database for MySQL: Azure Database for MySQL tools for Azure MCP Server Try it out and share your feedback! Start using Azure MCP Server with the MySQL tools today and let our cloud services become your AI agent’s most powerful ally. We’re counting on your feedback - every comment, suggestion, or bug-report helps us build better tools together. Stay tuned: more features and capabilities are on the horizon! Feel free to comment below or write to us with your feedback and queries at AskAzureDBforMySQL@service.microsoft.com.The Evolution of Conversational AI in Microsoft’s Ecosystem
Over the past two decades, conversational AI has shifted from a futuristic curiosity to a core part of how we interact with technology. And while many companies have shaped this field, one of the most influential players has consistently been Microsoft. From the early days of clippy (yes, that Clippy) to the cutting-edge Copilot ecosystem today, Microsoft’s journey mirrors the broader evolution of conversational AI itself. It’s a story of ambition, experimentation, setbacks, breakthroughs, and ultimately, transformation. In this blog, we’ll explore how conversational AI has developed within Microsoft’s ecosystem—how it started, the key milestones along the way, and where it’s all heading next. https://dellenny.com/the-evolution-of-conversational-ai-in-microsofts-ecosystem/GitHub Copilot for Python: Real-World Coding Scenarios & Practical Examples
When GitHub Copilot first launched, many developers wondered whether an AI pair-programmer could truly make an impact on everyday coding tasks. Today, after widespread adoption, the verdict is clear: Copilot can significantly boost productivity, reduce repetitive work, and help developers focus on high-level thinking. This is especially true for Python developers, who frequently deal with tasks ranging from data processing to API integration, automation, and web development. In this blog, we’ll explore real-world Python scenarios where GitHub Copilot shines. Whether you’re a beginner experimenting with your first scripts or a seasoned engineer working on large systems, Copilot can help streamline your workflow in ways that feel surprisingly human. https://dellenny.com/github-copilot-for-python-real-world-coding-scenarios-practical-examples/
