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Github

  • 128 installs
  • 1.5k repo stars
  • Updated July 20, 2026
  • vercel-labs/emulate

Local GitHub REST API emulator for testing repos, issues, PRs, and webhooks.

About

Emulated GitHub REST API for local development and integration testing. Covers repositories, issues, pull requests, comments, and webhook events with in-memory persistence. Starts via npx emulate --service github. Enables testing GitHub App integrations, OAuth flows against localhost, and CI scripts that call GitHub API without rate limits or network dependency on github.com. Supports seed data for repos and issues and inspection of API state during test runs.

  • Local GitHub REST API emulation for repos issues and PRs
  • In-memory persistence for integration test isolation
  • Webhook event simulation for GitHub App testing
  • No github.com rate limits during local development
  • Seed repos and issues for deterministic test scenarios

Github by the numbers

  • 128 all-time installs (skills.sh)
  • +6 installs in the week ending Jul 27, 2026 (Skillselion tracking)
  • Ranked #928 of 2,153 Testing & QA skills by installs in the Skillselion catalog
  • Security screen: HIGH risk (skills.sh audit)
  • Data as of Aug 4, 2026 (Skillselion catalog sync)
At a glance

github capabilities & compatibility

Capabilities
emulate github api · seed repos issues · simulate webhooks
Works with
github
Use cases
testing · api development
Runs
Runs locally
From the docs

What github says it does

Emulated GitHub REST API for local development and testing.
SKILL.md
npx skills add https://github.com/vercel-labs/emulate --skill github

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Listed on Skillselion
Installs128
repo stars1.5k
Security audit2 / 3 scanners passed
Last updatedJuly 20, 2026
Repositoryvercel-labs/emulate

How do I test GitHub API integrations locally?

Run emulated GitHub REST API locally to test repos, issues, PRs, and integrations without hitting github.com.

Who is it for?

Developers testing GitHub Apps, webhooks, or API integrations in CI.

Skip if: Real GitHub repository administration on github.com.

When should I use this skill?

User needs local GitHub API, test GitHub integrations, or emulate repos and issues.

What you get

GitHub REST calls hit local emulator with inspectable repo and issue state.

Files

SKILL.mdMarkdownGitHub ↗

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 URLEmulator 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: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

Issues

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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
# Check runs: list for suite, annotations
# Automatic suite status rollup from check run results

OAuth

# 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

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

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

# 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_..."

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

Related skills

FAQ

What GitHub resources are emulated?

Repositories, issues, pull requests, comments, and webhook events.

How do I start the emulator?

npx emulate --service github following the emulate family pattern.

Can I seed test data?

Yes. Seed configuration supports repos and issues for deterministic tests.

Is Github safe to install?

skills.sh reports 2 of 3 security scanners passed. Review the Security Audits panel on this page before installing in production.

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