/github

name: github
description: Emulated GitHub REST API for local development and testing. Use when the user needs to interact with GitHub API endpoints locally, test GitHub integrations, emulate repos/issues/PRs, set up GitHub OAuth flows, configure GitHub Apps, test webhooks, or work with actions/checks without hitting the real GitHub API. Triggers include "GitHub API", "emulate GitHub", "mock GitHub", "test GitHub OAuth", "GitHub App JWT", "local GitHub", or any task requiring a local GitHub API.
allowed-tools: Bash(npx emulate:*), Bash(emulate:*), Bash(curl:*)

GitHub API Emulator

Fully stateful GitHub REST API emulation. Creates, updates, and deletes persist in memory and affect related entities.

Start

# GitHub only
npx emulate --service github

# Default port
# http://localhost:4001

Or programmatically:

import { createEmulator } from 'emulate'

const github = await createEmulator({ service: 'github', port: 4001 })
// github.url === 'http://localhost:4001'

Auth

Pass tokens as `Authorization: Bearer <token>` or `Authorization: token <token>`.

curl http://localhost:4001/user \
  -H "Authorization: Bearer test_token_admin"

Public repo endpoints work without auth. Private repos and write operations require a valid token. When no token is provided, requests fall back to the first seeded user.

GitHub App JWT

Configure apps in the seed config with a private key. Sign a JWT with `{ iss: "<app_id>" }` using RS256. The emulator verifies the signature and resolves the app.

github:
  apps:
    - app_id: 12345
      slug: my-github-app
      name: My GitHub App
      private_key: |
        -----BEGIN RSA PRIVATE KEY-----
        ...
        -----END RSA PRIVATE KEY-----
      permissions:
        contents: read
        issues: write
      events: [push, pull_request]
      webhook_url: http://localhost:8080/github/webhook
      webhook_secret: my-webhook-secret
      description: My CI/CD bot
      installations:
        - installation_id: 100
          account: my-org
          repository_selection: all
          permissions:
            contents: read
          events: [push]
          repositories: [my-org/org-repo]

Pointing Your App at the Emulator

Environment Variable

GITHUB_EMULATOR_URL=http://localhost:4001

Octokit

import { Octokit } from '@octokit/rest'

const octokit = new Octokit({
  baseUrl: process.env.GITHUB_EMULATOR_URL ?? 'https://api.github.com',
  auth: 'test_token_admin',
})

OAuth URL Mapping

| Real GitHub URL | Emulator URL | |-----------------|-------------| | `https://github.com/login/oauth/authorize` | `$GITHUB_EMULATOR_URL/login/oauth/authorize` | | `https://github.com/login/oauth/access_token` | `$GITHUB_EMULATOR_URL/login/oauth/access_token` | | `https://api.github.com/user` | `$GITHUB_EMULATOR_URL/user` |

Auth.js / NextAuth.js

import GitHub from '@auth/core/providers/github'

GitHub({
  clientId: process.env.GITHUB_CLIENT_ID,
  clientSecret: process.env.GITHUB_CLIENT_SECRET,
  authorization: {
    url: `${process.env.GITHUB_EMULATOR_URL}/login/oauth/authorize`,
  },
  token: {
    url: `${process.env.GITHUB_EMULATOR_URL}/login/oauth/access_token`,
  },
  userinfo: {
    url: `${process.env.GITHUB_EMULATOR_URL}/user`,
  },
})

Seed Config

tokens:
  test_token_admin:
    login: admin
    scopes: [repo, user, admin:org, admin:repo_hook]

github:
  users:
    - login: octocat
      name: The Octocat
      email: octocat@github.com
      bio: I am the Octocat
      company: GitHub
      location: San Francisco
      blog: https://github.blog
      twitter_username: github
      site_admin: false
  orgs:
    - login: my-org
      name: My Organization
      description: A test organization
      email: org@example.com
  repos:
    - owner: octocat
      name: hello-world
      description: My first repository
      language: JavaScript
      topics: [hello, world]
      default_branch: main
      private: false
    - owner: my-org
      name: org-repo
      description: An organization repository
      language: TypeScript
  oauth_apps:
    - client_id: Iv1.abc123
      client_secret: secret_abc123
      name: My Web App
      redirect_uris:
        - http://localhost:3000/api/auth/callback/github

Repos are auto-initialized with a commit, branch, and README unless `auto_init: false` is set.

Pagination

All list endpoints support `page` and `per_page` query params with `Link` headers:

curl "http://localhost:4001/repos/octocat/hello-world/issues?page=1&per_page=10" \
  -H "Authorization: Bearer $TOKEN"

API Endpoints

Users

# Authenticated user
curl http://localhost:4001/user -H "Authorization: Bearer $TOKEN"

# Update profile
curl -X PATCH http://localhost:4001/user \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"bio": "Hello!"}'

# Get user by username
curl http://localhost:4001/users/octocat

# List users
curl http://localhost:4001/users

# User repos / orgs / followers / following
curl http://localhost:4001/users/octocat/repos
curl http://localhost:4001/users/octocat/orgs
curl http://localhost:4001/users/octocat/followers
curl http://localhost:4001/users/octocat/following

# User hovercard
curl http://localhost:4001/users/octocat/hovercard

# User emails
curl http://localhost:4001/user/emails -H "Authorization: Bearer $TOKEN"

Repositories

# Get repo
curl http://localhost:4001/repos/octocat/hello-world

# Create user repo
curl -X POST http://localhost:4001/user/repos \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "new-repo", "private": false}'

# Create org repo
curl -X POST http://localhost:4001/orgs/my-org/repos \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "org-project"}'

# Update repo
curl -X PATCH http://localhost