github-mcp-server copilot-instructions.md

Instructions for GitHub's MCP server, a Go program that lets AI tools work with GitHub through natural-language requests. They describe the project structure, important build checks, coding standards, and rules for changing tools or endpoints.

In plain words
What is it for?
Building and validating the server, modifying MCP tools or endpoints, preserving reusable exported functions, and maintaining clear, focused Go changes.
Why use it?
They help coding assistants understand which parts of the server matter and which checks must pass before a commit. This reduces broken integrations and unclear or inconsistent changes.

Instructions file for GitHub Copilot

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/github/github-mcp-server/copilot-instructions
Clone the repo
git clone --depth 1 https://github.com/github/github-mcp-server

Made for: GitHub Copilot.

Per session 3,217 This file is loaded in full into every session.
When invoked 3,217 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.03217 $0.03217
Opus 5 $0.01608 $0.01608
Sonnet 5 $0.00643 $0.00643
Haiku 4.5 $0.00322 $0.00322

Measured yesterday against content hash 83a4bbbae137, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

github-mcp-server copilot-instructions.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.github/copilot-instructions.md · 291 lines

How it starts

The opening of the file, as written. The whole thing — 291 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GitHub MCP Server - Copilot Instructions

Project Overview

This is the GitHub MCP Server, a Model Context Protocol (MCP) server that connects AI tools to GitHub's platform. It enables AI agents to manage repositories, issues, pull requests, workflows, and more through natural language.

Key Details:

  • Language: Go 1.24+ (~38k lines of code)
  • Type: MCP server application with CLI interface
  • Primary Package: github-mcp-server (stdio MCP server - this is the main focus)
  • Secondary Package: mcpcurl (testing utility - don't break it, but not the priority)
  • Framework: Uses modelcontextprotocol/go-sdk for MCP protocol, google/go-github for GitHub API
  • Size: ~60MB repository, 70 Go files
  • Library Usage: This repository is also used as a library by the remote server. Functions that could be called by other repositories should be exported (capitalized), even if not required internally. Preserve existing export patterns.

Code Quality Standards:

  • Popular Open Source Repository - High bar for code quality and clarity
  • Comprehension First - Code must be clear to a wide audience
  • Clean Commits - Atomic, focused changes with clear messages
  • Structure - Always maintain or improve, never degrade
  • Code over Comments - Prefer self-documenting code; comment only when necessary

Critical Build & Validation Steps

Required Commands (Run Before Committing)

ALWAYS run these commands in this exact order before using report_progress or finishing work:

  1. Format Code: script/lint (runs gofmt -s -w . then golangci-lint)
  2. Run Tests: script/test (runs go test -race ./...)
  3. Update Documentation: script/generate-docs (if you modified MCP tools/toolsets)

These commands are FAST: Lint ~1s, Tests ~1s (cached), Build ~1s

When Modifying MCP Tools/Endpoints

If you change any MCP tool definitions or schemas:

  1. Run tests with UPDATE_TOOLSNAPS=true go test ./... to update toolsnaps
  2. Commit the updated .snap files in pkg/github/__toolsnaps__/
  3. Run script/generate-docs to update README.md
  4. Toolsnaps document API surface and ensure changes are intentional

Read the full file on GitHub · 291 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 291 lines · 3,217 tokens per session scan A 83a4bbbae137

Subscribe to this mod's changes

github-mcp-server copilot-instructions.md is an instructions file published in the GitHub repository github/github-mcp-server (32,608 stars, last pushed 3d ago), licensed MIT. It adds 3,217 tokens to every session, about $0.0161 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other instructions, from other repositories