🛡️ Copilot Security Instructions

A comprehensive toolkit to guide GitHub Copilot toward secure coding practices. This project includes customizable instructions and security-focused prompts to help development teams identify and mitigate security risks effectively.

Designed for security-conscious teams, this configuration ensures Copilot suggests safer code patterns, avoids common vulnerabilities, and reinforces best practices — all without disrupting your workflow.

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🔐 What's Inside

This project offers:

• Secure-by-default guidance for all languages (e.g., input validation, secret handling, safe logging).
• Language-specific secure patterns:
  • ☕ Java
  • 🟩 Node.js
  • 🟦 C#
  • 🐍 Python
• "Do Not Suggest" lists to block risky Copilot completions (e.g., eval, inline SQL, insecure deserialization).
• AI hallucination protections to prevent package spoofing, non-existent APIs, and misinformation risks.
• Mentorship-style tips to help newer engineers build secure coding habits.
• Custom agents & Agent Skills under agents/ and skills/ for repeatable AppSec workflows inside Copilot.
• An installable GitHub Copilot CLI plugin under plugins/copilot-security for reusable AppSec agents and skills across projects.
• An MCP server for seamless integration of these prompts into other projects.

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🗂️ Prompt Catalogue

Explore the available prompts and their intended use cases:

These prompt files live under prompts/ in this repo and are intended to be copied into a consuming repository’s .github/prompts/.

Recommended workflow: start with the application-security-orchestrator agent (see agents/application-security-orchestrator.agent.md). It standardizes intake, then hands off to specialist agents (Analyst/Architect/Engineer) depending on whether you want findings, a threat model, or implemented fixes.

| Prompt | Description | Intended Use | | --- | --- | --- | | access-control-review.prompt.md | Review and report on access control / authorization architecture for project. | Perform analysis of the current architecture for access control and authorization within the project. | | assess-logging.prompt.md | Identify unsafe logging and exposure of sensitive data. | Audit log output for leaks and recommend safer patterns. | | business-logic-review.prompt.md | Analyze overall business logic flow and decision making. | Map application behavior and critique critical logic paths. | | check-access-controls.prompt.md | Audit authorization and access control weaknesses. | Ensure RBAC/ABAC enforcement and consistent permission checks. | | check-for-secrets.prompt.md | Detect hardcoded secrets and credentials. | Locate embedded keys or tokens and suggest secure storage. | | check-for-unvalidated-genai-acceptances.prompt.md | Find unvalidated AI-generated code or hallucinated assets. | Verify that AI suggestions are real, tested, and documented. | | add-content-security-policy.prompt.md | Design, implement, and roll out a new Content Security Policy (CSP) safely. | Add CSP to a web app with a deployable policy string, rollout plan, and verification steps. | | csp-review.prompt.md | Review a web application’s Content-Security-Policy (CSP) for XSS resistance, safe third-party usage, and deployability. | Evaluate an existing CSP policy and recommend hardening + rollout steps. | | dependency-cve-triage.prompt.md | Triage a known CVE against a project's dependency: explain the exploit, assess reachability and configuration, and produce a structured Dependency Tracker report. | Analyze a specific CVE's impact on local code, determine exploitability, and generate a concise triage report. | | review-auth-flows.prompt.md | Evaluate authentication logic and session handling. | Review login flows for common risks and best practices. | | scan-for-insecure-apis.prompt.md | Spot deprecated or insecure API usage. | Replace risky APIs with modern, safer alternatives. | | secure-code-review.prompt.md | Perform a comprehensive security review of the codebase. | Conduct an end-to-end audit for security issues. | | threat-model.prompt.md | Produce a lightweight threat model using the 4Q approach with scoped threats, mitigations, and a validation plan. | Threat-model a feature/system or PR diff and generate durable artifacts. | | validate-input-handling.prompt.md | Check for missing or unsafe input validation. | Evaluate request handling for validation and sanitization gaps. |

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🧑‍💻 Agents

| Agent | Purpose | | --- | --- | | application-security-orchestrator | Standardize intake and route to the right specialist. | | application-security-analyst | Read-only findings + remediation guidance. | | application-security-architect | Threat models + guardrails + ADRs. | | application-security-engineer | Implement fixes + tests with minimal diffs. |

🧩 Skills

| Skill | Intended use | | --- | --- | | secure-code-review | Repeatable security review workflow + findings template. | | access-control-review | Review identity, access control, and authorization architecture with evidence-first reporting. | | input-validation-hardening | Tighten validation boundaries and parsing safety. | | dependency-cve-triage | CVE reachability + remediation plan workflow. | | secrets-and-logging-hygiene | Prevent secret leaks and add redaction defaults. | | genai-acceptance-review | Prevent over-trust and prompt/tool injection risks. | | threat-model | Full 4Q threat modeling workflow with CLI-friendly Mermaid docs and validation helpers. | | secure-fix-validation | Prove fixes work and don’t regress behavior. |

📦 How to Use in a Real Project

Tip for contributors: when adding a file under prompts/, update the Prompt Catalogue table.

Option 1: Leveraging Static Files

This option is best when you want to vendor a fixed set of guidance files directly into a repository instead of installing the reusable CLI plugin.

Copy the components you want from this repository into the matching .github/ locations in your target project:

| From this repository | Copy into target project | Purpose | | --- | --- | --- | | copilot-instructions.md | .github/copilot-instructions.md | Repository-wide default coding and security guidance | | prompts/*.prompt.md | .github/prompts/ | Reusable prompt files that can be run directly in Copilot | | agents/*.agent.md | .github/agents/ | Reusable specialist agents such as analyst, architect, or engineer | | skills/**/SKILL.md and skill-local files | .github/skills/ | On-demand skills, including any helper scripts kept inside each skill directory | | instructions/*.instructions.md | .github/instructions/ | Path-specific instructions for matching file globs |

Notes:

• If you copy a skill directory, copy the entire folder, not just SKILL.md. Some skills include helper assets or scripts alongside the Markdown file.
• The root-level instructions/ folder in this repository is currently empty, so there are no path-specific instruction files to copy right now.
• If you only need a subset, copy only the prompts, agents, or skills you plan to use.

1. Copy copilot-instructions.md into your repo under .github/copilot-instructions.md.

2. Copy whichever reusable folders and files you want to adopt:

   • prompts into .github/prompts/
   • agents into .github/agents/
   • skills into .github/skills/
   • instructions into .github/instructions/ when this repository provides them

3. Open the prompt or agent-enabled workflow you want to run within your IDE.

4. For prompt files, click the Run Prompt button at the top-right of the file.

   

   ℹ️ Note: If you don't see the run prompt button; check to make sure the Chat: Prompt Files functionality is enabled in your settings

5. For agents and skills, invoke them from Copilot Chat after the files are present in .github/agents/ and .github/skills/.

Option 2: Leveraging the MCP Server

The MCP server simplifies the integration of secure coding prompts into your workflow. Follow these steps:

Run MCP from source

1. Install dependencies

   npm install
   

2. Setup environment

   cp .env.example .env
   

   The MCP server reads configuration from a .env file. Customize the following variables as needed:

   | Variable | Description | Default | | --- | --- | --- | | server.port | Port the MCP server listens on. | 8080 | | server.ssl | Whether to use ssl for express server | false | | server.ssl.pfx | Path to pfx file | localhost.pfx | | server.ssl.pfx.passphrase | Passphrase for pfx file | PFX_PASSPHRASE | | server.hostname | Hostname the server binds to. | localhost | | logger.transports.console.enabled | Enable console logging output. | false | | logger.transports.console.level | Log level for console output. | info | | logger.transports.amqp.enabled | Enable AMQP-based logging. | false | | logger.transports.amqp.level | Log level for AMQP transport. | http | | logger.transports.amqp.hostname | Hostname of the AMQP broker. | localhost | | logger.transports.amqp.port | Port for the AMQP broker. | 5672 | | logger.transports.amqp.username | Username for AMQP authentication. | guest | | logger.transports.amqp.password | Password for AMQP authentication. | guest | | logger.transports.amqp.exchange | Exchange name used for AMQP logging. | logs | | logger.transports.amqp.vhost | Virtual host for AMQP logging. | /logs | | logger.transports.amqp.heartbeat | Heartbeat interval in seconds. | 60 | | logger.transports.amqp.locale | Locale for the AMQP connection. | en_US | | logger.transports.amqp.type | AMQP exchange type. | direct | | logger.transports.amqp.durable | Whether the AMQP exchange is durable. | false |

3. Start the server

   npm start
   

Run MCP in Docker

1. Build docker container

   docker build -t copilot-security-mcp .
   

2. Run docker container

   docker run -d -p 8080:8080 copilot-security-mcp
   

Configuring VSCode for MCP

1. Open VSCode and run the MCP: Open User Configuration command.

2. Add the following JSON configuration:

   {
      "servers": {
         "copilot-instructions-mcp": {
            "url": "http://localhost:8080/mcp"
         }
      }
   }
   

3. Save the configuration.

4. Navigate to the Extensions menu in VSCode.

5. Locate the copilot-instructions-mcp server, click the settings cog, and select start server.