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(curl:*)
---

# GitHub API Emulator

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

## Start

Local listeners bind to `127.0.0.1` by default. For access from containers or other machines, pass `--host 0.0.0.0` to the CLI or `hostname: '0.0.0.0'` to `createEmulator`. Configure `--base-url` or `baseUrl` for advertised URLs reachable by those clients.

```bash
# GitHub only
npx emulate --service github

# Default port
# http://localhost:4001
```

Or programmatically:

```typescript
import { createEmulator } from 'emulate'

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

For a programmatic GitHub App, omit `private_key` and read the generated RSA key from the instance:

```typescript
const github = await createEmulator({
  service: 'github',
  port: 4001,
  seed: {
    github: {
      users: [{ login: 'octocat' }],
      apps: [{
        app_id: 12345,
        slug: 'my-github-app',
        name: 'My GitHub App',
        installations: [{ installation_id: 100, account: 'octocat' }],
      }],
    },
  },
})

const privateKey = github.generatedSecrets.find(
  secret => secret.kind === 'github.app_private_key' && secret.id === '12345',
)?.value
```

The key remains stable across `github.reset()`. Explicit keys are not included in `generatedSecrets`.

The Next.js and Nuxt adapters also generate omitted keys. Retain the returned handler and call its server-only `generatedSecrets()` method. With persistence configured, the identity survives cold starts. Keep snapshots private because they contain the signing key, and require custom persistence backends to implement atomic `initialize()` semantics.

For the CLI, omit `private_key` only when requesting a private delivery file:

```bash
npx emulate start --service github --seed emulate.config.yaml \
  --generated-secrets-file .emulate-secrets.json
```

The destination must not exist. emulate removes inherited ACLs, verifies effective owner-only access, and publishes complete JSON before any listener or portless alias starts. Handled startup failures remove the invocation-owned artifact. A hard termination can leave a complete artifact that must be removed manually after confirming no invocation is using it. Read `generatedSecrets` from the artifact, then keep the file out of source control. Linux requires `setfacl` and `getfacl` from the `acl` package. The flag fails closed when access controls cannot be verified and is not supported on Windows. Without `--generated-secrets-file`, CLI seed files still require `private_key`.

## Auth

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

```bash
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.

Installation access tokens act as the configured GitHub App bot for repository writes. Repository ownership, selected repository access, and requested App permissions remain enforced. Pull request merges require `contents: write` on the base repository. Pull request branch updates require `pull_requests: write` on the pull request repository and `contents: write` on the head repository.

### GitHub App JWT

Configure apps in the seed config with an explicit, valid private key when using the CLI without generated secrets. Sign a JWT with `{ iss: "<app_id>" }` using RS256. The emulator verifies the signature and resolves the app.

```yaml
github:
  apps:
    - app_id: 12345
      slug: my-github-app
      name: My GitHub App
      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]
```

This example intentionally omits `private_key` for programmatic and adapter usage, where the emulator generates an RSA key and exposes it through `generatedSecrets`. For CLI usage, request a private delivery file with `--generated-secrets-file <path>` or provide your own valid key. Without that flag, CLI seed files require `private_key`; do not use a placeholder PEM.

## Pointing Your App at the Emulator

### Environment Variable

```bash
GITHUB_EMULATOR_URL=http://localhost:4001
```

### Octokit

```typescript
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

```typescript
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

```yaml
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
      members:
        - login: octocat
          role: admin
  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
```

Organization `members` are optional. Each entry references a seeded user by `login`; `role` defaults to `member`, and `admin` maps to the organization administrator role. Unknown users are ignored. Seeded memberships use the synthetic `members` team and grant private organization repository access.

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:

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

## API Endpoints

### Users

```bash
# 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

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

# Get repo by numeric ID
curl http://localhost:4001/repositories/1

# 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:4001/repos/octocat/hello-world \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"description": "Updated description"}'

# Delete repo (cascades issues, PRs, etc.)
curl -X DELETE http://localhost:4001/repos/octocat/hello-world \
  -H "Authorization: Bearer $TOKEN"

# Topics, languages, contributors, forks, collaborators, tags, transfer
```

### Contents & Commit History

```bash
# Read a file or list a directory at a branch, tag, or commit
curl "http://localhost:4001/repos/octocat/hello-world/contents/README.md?ref=main"

# Request raw bytes from a file Contents or README response with GitHub's raw media type
curl "http://localhost:4001/repos/octocat/hello-world/contents/README.md?ref=main" \
  -H "Accept: application/vnd.github.raw+json"

# Download raw file content from the URL advertised by contents and commit responses
curl http://localhost:4001/octocat/hello-world/raw/main/README.md

# Create or update a file and commit the change
curl -X PUT http://localhost:4001/repos/octocat/hello-world/contents/notes.txt \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"message": "Update notes", "content": "aGVsbG8K"}'

# List commits, get a commit with file stats, or compare refs
curl http://localhost:4001/repos/octocat/hello-world/commits
curl http://localhost:4001/repos/octocat/hello-world/commits/main
curl http://localhost:4001/repos/octocat/hello-world/compare/v1.0.0...main
```

### Issues

```bash
# List issues (filter by state, labels, assignee, milestone, creator, since)
curl "http://localhost:4001/repos/octocat/hello-world/issues?state=open&labels=bug"

# Create issue
curl -X POST http://localhost:4001/repos/octocat/hello-world/issues \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title": "Bug report", "body": "Details here", "labels": ["bug"]}'

# Get / update / lock / unlock / timeline / events / assignees
```

### Pull Requests

```bash
# List PRs
curl "http://localhost:4001/repos/octocat/hello-world/pulls?state=open"

# Create PR
curl -X POST http://localhost:4001/repos/octocat/hello-world/pulls \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title": "Feature", "head": "feature-branch", "base": "main"}'

# Merge PR (enforces branch protection)
curl -X PUT http://localhost:4001/repos/octocat/hello-world/pulls/1/merge \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"merge_method": "squash"}'

# Commits, files, requested reviewers, update branch
```

### Comments

```bash
# Issue comments: full CRUD
curl http://localhost:4001/repos/octocat/hello-world/issues/1/comments
curl -X POST http://localhost:4001/repos/octocat/hello-world/issues/1/comments \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"body": "Looks good!"}'

# Comment by ID (cross-resource)
curl http://localhost:4001/repos/octocat/hello-world/issues/comments/1

# PR review comments
curl http://localhost:4001/repos/octocat/hello-world/pulls/1/comments

# Commit comments
curl http://localhost:4001/repos/octocat/hello-world/commits/abc123/comments

# Repo-wide comment listings
curl http://localhost:4001/repos/octocat/hello-world/issues/comments
curl http://localhost:4001/repos/octocat/hello-world/pulls/comments
curl http://localhost:4001/repos/octocat/hello-world/comments
```

### Reviews

```bash
# List / create / get / update / submit / dismiss reviews
curl http://localhost:4001/repos/octocat/hello-world/pulls/1/reviews
curl -X POST http://localhost:4001/repos/octocat/hello-world/pulls/1/reviews \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"event": "APPROVE", "body": "LGTM"}'
```

### Labels & Milestones

Full CRUD for labels and milestones. Add/remove labels from issues, replace all labels. List labels for a milestone.

### Branches & Git Data

```bash
# List branches
curl http://localhost:4001/repos/octocat/hello-world/branches

# Branch protection CRUD (status checks, PR reviews, enforce admins)
curl -X PUT http://localhost:4001/repos/octocat/hello-world/branches/main/protection \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"required_status_checks": {"strict": true, "contexts": ["ci"]}}'

# Refs, commits, trees (recursive), blobs, tags, matching-refs
```

### Organizations & Teams

```bash
# List all orgs / user's orgs / get org / update org
curl http://localhost:4001/organizations
curl http://localhost:4001/user/orgs -H "Authorization: Bearer $TOKEN"
curl http://localhost:4001/orgs/my-org
curl -X PATCH http://localhost:4001/orgs/my-org \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"description": "Updated org"}'

# Org members: list, get, remove
curl http://localhost:4001/orgs/my-org/members
curl http://localhost:4001/orgs/my-org/members/octocat
curl -X DELETE http://localhost:4001/orgs/my-org/members/octocat \
  -H "Authorization: Bearer $TOKEN"

# Org memberships: get, set (invite/update role)
curl http://localhost:4001/orgs/my-org/memberships/octocat -H "Authorization: Bearer $TOKEN"
curl -X PUT http://localhost:4001/orgs/my-org/memberships/octocat \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"role": "admin"}'

# Teams: CRUD
curl http://localhost:4001/orgs/my-org/teams
curl -X POST http://localhost:4001/orgs/my-org/teams \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "engineering", "privacy": "closed"}'

# Team members and memberships
curl http://localhost:4001/orgs/my-org/teams/engineering/members
curl -X PUT http://localhost:4001/orgs/my-org/teams/engineering/memberships/octocat \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"role": "maintainer"}'

# Team repos: list, add, remove
curl http://localhost:4001/orgs/my-org/teams/engineering/repos
curl -X PUT http://localhost:4001/orgs/my-org/teams/engineering/repos/my-org/org-repo \
  -H "Authorization: Bearer $TOKEN"

# Legacy team endpoints by ID
curl http://localhost:4001/teams/1
curl http://localhost:4001/teams/1/members
```

### GitHub Apps

```bash
# Get authenticated app (requires JWT auth)
curl http://localhost:4001/app \
  -H "Authorization: Bearer <jwt>"

# List app installations
curl http://localhost:4001/app/installations \
  -H "Authorization: Bearer <jwt>"

# Get installation
curl http://localhost:4001/app/installations/100 \
  -H "Authorization: Bearer <jwt>"

# Create installation access token (mints ghs_... token)
curl -X POST http://localhost:4001/app/installations/100/access_tokens \
  -H "Authorization: Bearer <jwt>" \
  -H "Content-Type: application/json" \
  -d '{"permissions": {"contents": "read"}}'

# Find installation for repo / org / user
curl http://localhost:4001/repos/my-org/org-repo/installation
curl http://localhost:4001/orgs/my-org/installation
curl http://localhost:4001/users/octocat/installation
```

App webhook delivery: when events occur, the emulator POSTs `event_callback` payloads to configured `webhook_url` with `X-GitHub-Event` and `X-Hub-Signature-256` headers.

### Releases

```bash
# Create release
curl -X POST http://localhost:4001/repos/octocat/hello-world/releases \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"tag_name": "v1.0.0", "name": "v1.0.0"}'

# List, get, latest, by tag, generate notes

# Release assets: list, upload
curl http://localhost:4001/repos/octocat/hello-world/releases/1/assets
curl -X POST http://localhost:4001/repos/octocat/hello-world/releases/1/assets \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/octet-stream" \
  -H "name: binary.zip" \
  --data-binary @binary.zip
```

### Webhooks

```bash
# Create webhook (real HTTP delivery on state changes)
curl -X POST http://localhost:4001/repos/octocat/hello-world/hooks \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"config": {"url": "http://localhost:8080/webhook"}, "events": ["push", "pull_request"]}'

# Full CRUD, ping, test, deliveries
# Org webhooks also supported
```

### Search

```bash
# Search repositories
curl "http://localhost:4001/search/repositories?q=language:JavaScript+user:octocat"

# Search issues and PRs
curl "http://localhost:4001/search/issues?q=repo:octocat/hello-world+is:open"

# Search users, code, commits, topics, labels
```

### Actions

```bash
# Workflows: list, get, enable/disable, dispatch
# Workflow runs: list, get, cancel, rerun, delete, logs
# Jobs: list, get, logs
# Artifacts: list, get, delete
# Secrets: repo + org CRUD
```

### Checks

```bash
# Create check run
curl -X POST http://localhost:4001/repos/octocat/hello-world/check-runs \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "CI", "head_sha": "abc123", "status": "completed", "conclusion": "success"}'

# Check suites: create, get, rerequest, preferences, list by ref. Ref based lookups accept branch and tag refs containing slashes.
# Check runs: list for suite, annotations. Ref based lookups accept branch and tag refs containing slashes.
# Automatic suite status rollup from check run results
```

### OAuth

```bash
# Authorize (browser flow, shows user picker)
# GET /login/oauth/authorize?client_id=...&redirect_uri=...&scope=...&state=...

# Token exchange
curl -X POST http://localhost:4001/login/oauth/access_token \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{"client_id": "Iv1.abc123", "client_secret": "secret_abc123", "code": "<code>"}'

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

# OAuth app management (settings)
curl http://localhost:4001/settings/applications -H "Authorization: Bearer $TOKEN"
curl http://localhost:4001/settings/connections/applications/Iv1.abc123 -H "Authorization: Bearer $TOKEN"

# Revoke OAuth app
curl -X POST http://localhost:4001/settings/connections/applications/Iv1.abc123/revoke \
  -H "Authorization: Bearer $TOKEN"
```

### Misc

```bash
curl http://localhost:4001/rate_limit
curl http://localhost:4001/meta
curl http://localhost:4001/emojis
curl http://localhost:4001/versions
curl http://localhost:4001/octocat
curl http://localhost:4001/zen
```

## Common Patterns

### Create Repo, Issue, and PR

```bash
TOKEN="test_token_admin"
BASE="http://localhost:4001"

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

# Create issue
curl -X POST $BASE/repos/admin/my-project/issues \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title": "First issue"}'

# Create PR
curl -X POST $BASE/repos/admin/my-project/pulls \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title": "First PR", "head": "feature", "base": "main"}'
```

### GitHub App Installation Token Flow

```bash
# 1. Sign a JWT with { iss: "12345" } using the app's private key (RS256)
# 2. Create an installation access token
curl -X POST $BASE/app/installations/100/access_tokens \
  -H "Authorization: Bearer <jwt>" \
  -H "Content-Type: application/json" \
  -d '{"permissions": {"contents": "read", "issues": "write"}}'
# Returns { "token": "ghs_...", ... }

# 3. Use the installation token to call API endpoints
curl $BASE/repos/my-org/org-repo \
  -H "Authorization: Bearer ghs_..."

# Inspect minted installation-token metadata without token values
curl $BASE/_emulate/installation-tokens
```

The inspection route is emulator-specific. It lists App, installation, account, permissions, repository access, issuance, expiry, and lifecycle status without accepting or returning token values or token-derived identifiers. Expiry is informational and does not change authorization behavior.

### OAuth Flow

1. Redirect user to `$GITHUB_EMULATOR_URL/login/oauth/authorize?client_id=...&redirect_uri=...&scope=user+repo&state=...`
2. User picks a seeded user on the emulator's UI
3. Emulator redirects back with `?code=...&state=...`
4. Exchange code for token via `POST /login/oauth/access_token`
5. Use token to call API endpoints

## Custom emulators alongside built-ins

Use `npx emulate init --custom inventory` to scaffold a third-party API emulator and test. Register it in `emulate.config.ts` with `defineConfig` from `emulate`, alongside built-in entries such as `{ emulator: "github" }`. Run `npx emulate start --watch` to reload imports and inspect custom state at the printed `/_emulate` URL. Successful reloads reset the run to seed. Existing flat seed configs still work; `--config` selects an explicit file. For authoring and testing third-party API emulators, see https://emulate.dev/docs/custom-emulators.

From vercel-labs/emulate at c77cb73, shown as plain text under its license: Apache-2.0 (permissive). The license text is in LICENSE.

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