Test agents and software against stateful API and database clones

Run production-shaped services locally: GitHub, Stripe, Slack, Postgres, MySQL, SQLite, DuckDB, warehouses, data lakes, and 180+ more. Same APIs, familiar errors, deterministic state, no real credentials.

$ npx -p api-emulator api --portless

api-emulator v0.6.0  api-emulator-registry: 188 services

  ADP                  https://adp.api-emulator.localhost
  Adyen                https://adyen.api-emulator.localhost
  Amazon Seller        https://amazon-seller.api-emulator.localhost
  Anotes               https://anotes.api-emulator.localhost
  App Store Connect    https://app-store-connect.api-emulator.localhost
  Apple                https://apple.api-emulator.localhost
  Apple Maps           https://apple-maps.api-emulator.localhost
  Apple Music          https://apple-music.api-emulator.localhost
  Apple Podcasts       https://apple-podcasts.api-emulator.localhost
  Applecare            https://applecare.api-emulator.localhost
  Applovin             https://applovin.api-emulator.localhost
  Argo                 https://argo.api-emulator.localhost
  arXiv                https://arxiv.api-emulator.localhost
  Attio                https://attio.api-emulator.localhost
  Audible              https://audible.api-emulator.localhost
  Auth0                https://auth0.api-emulator.localhost
  AWS                  https://aws.api-emulator.localhost
  Azure                https://azure.api-emulator.localhost
  Backblaze            https://backblaze.api-emulator.localhost
  Baseten              https://baseten.api-emulator.localhost
  Bilt                 https://bilt.api-emulator.localhost
  Bland                https://bland.api-emulator.localhost
  Brave Search         https://brave-search.api-emulator.localhost
  Brex                 https://brex.api-emulator.localhost
  Browserbase          https://browserbase.api-emulator.localhost
  Canva                https://canva.api-emulator.localhost
  Canvas               https://canvas.api-emulator.localhost
  Capcut               https://capcut.api-emulator.localhost
  Clay                 https://clay.api-emulator.localhost
  Clerk                https://clerk.api-emulator.localhost
  CodeRabbit           https://coderabbit.api-emulator.localhost
  Coinbase             https://coinbase.api-emulator.localhost
  Concur               https://concur.api-emulator.localhost
  CoreWeave            https://coreweave.api-emulator.localhost
  Craigslist           https://craigslist.api-emulator.localhost
  Crusoe               https://crusoe.api-emulator.localhost
  Databricks           https://databricks.api-emulator.localhost
  Datadog              https://datadog.api-emulator.localhost
  Decagon              https://decagon.api-emulator.localhost
  Deel                 https://deel.api-emulator.localhost
  Devin                https://devin.api-emulator.localhost
  DigitalOcean         https://digitalocean.api-emulator.localhost
  Discord              https://discord.api-emulator.localhost
  Docusign             https://docusign.api-emulator.localhost
  DoorDash             https://doordash.api-emulator.localhost
  Doppler              https://doppler.api-emulator.localhost
  Duke Energy          https://duke-energy.api-emulator.localhost
  E Trade              https://e-trade.api-emulator.localhost
  eBay Seller          https://ebay-seller.api-emulator.localhost
  Eight Sleep          https://eight-sleep.api-emulator.localhost
  ElevenLabs           https://elevenlabs.api-emulator.localhost
  Ethos                https://ethos.api-emulator.localhost
  EXA                  https://exa.api-emulator.localhost
  Facebook Messenger   https://facebook-messenger.api-emulator.localhost
  Fidelity             https://fidelity.api-emulator.localhost
  Figma                https://figma.api-emulator.localhost
  Fireworks            https://fireworks.api-emulator.localhost
  Flightradar24        https://flightradar24.api-emulator.localhost
  Geico                https://geico.api-emulator.localhost
  GitHub               https://github.api-emulator.localhost
  Gong                 https://gong.api-emulator.localhost
  Goodreads            https://goodreads.api-emulator.localhost
  Google               https://google.api-emulator.localhost
  Google Analytics     https://google-analytics.api-emulator.localhost
  Google Classroom     https://google-classroom.api-emulator.localhost
  Google Flights       https://google-flights.api-emulator.localhost
  Google Forms         https://google-forms.api-emulator.localhost
  Google Maps          https://google-maps.api-emulator.localhost
  Google Play          https://google-play.api-emulator.localhost
  Grafana              https://grafana.api-emulator.localhost
  Granola              https://granola.api-emulator.localhost
  Greptile             https://greptile.api-emulator.localhost
  Gusto                https://gusto.api-emulator.localhost
  Harvey               https://harvey.api-emulator.localhost
  HashiCorp Vault      https://hashicorp-vault.api-emulator.localhost
  Hubspot              https://hubspot.api-emulator.localhost
  Hugging Face         https://huggingface.api-emulator.localhost
  iMessage             https://imsg.api-emulator.localhost
  Interactive Brokers  https://interactive-brokers.api-emulator.localhost
  Intercom             https://intercom.api-emulator.localhost
  Intuit               https://intuit.api-emulator.localhost
  Jira                 https://jira.api-emulator.localhost
  JoinWarp Payroll     https://joinwarp-payroll.api-emulator.localhost
  LegalZoom            https://legalzoom.api-emulator.localhost
  Legora               https://legora.api-emulator.localhost
  Lemonade             https://lemonade.api-emulator.localhost
  Lexis                https://lexis.api-emulator.localhost
  Linear               https://linear.api-emulator.localhost
  Linkedin             https://linkedin.api-emulator.localhost
  Listen Labs          https://listenlabs.api-emulator.localhost
  Lucent               https://lucent.api-emulator.localhost
  Marketo              https://marketo.api-emulator.localhost
  MediaWiki            https://mediawiki.api-emulator.localhost
  Mercury              https://mercury.api-emulator.localhost
  Metlife              https://metlife.api-emulator.localhost
  Microsoft            https://microsoft.api-emulator.localhost
  Mintlify             https://mintlify.api-emulator.localhost
  Mixpanel             https://mixpanel.api-emulator.localhost
  Mobbin               https://mobbin.api-emulator.localhost
  Modal                https://modal.api-emulator.localhost
  MongoDB Atlas        https://mongoatlas.api-emulator.localhost
  Neon                 https://neon.api-emulator.localhost
  Netlify              https://netlify.api-emulator.localhost
  Nextdoor             https://nextdoor.api-emulator.localhost
  NYTimes              https://nytimes.api-emulator.localhost
  OCI                  https://oci.api-emulator.localhost
  Oculus               https://oculus.api-emulator.localhost
  Okta                 https://okta.api-emulator.localhost
  Oura                 https://oura.api-emulator.localhost
  Patreon              https://patreon.api-emulator.localhost
  PayPal               https://paypal.api-emulator.localhost
  Pinterest            https://pinterest.api-emulator.localhost
  PirateBay            https://piratebay.api-emulator.localhost
  PlanetScale          https://planetscale.api-emulator.localhost
  PlayStation          https://playstation.api-emulator.localhost
  Postbridge           https://postbridge.api-emulator.localhost
  PostHog              https://posthog.api-emulator.localhost
  Prime Music          https://prime-music.api-emulator.localhost
  Privy                https://privy.api-emulator.localhost
  Progressive          https://progressive.api-emulator.localhost
  Proton Mail          https://proton-mail.api-emulator.localhost
  Qualtrics            https://qualtrics.api-emulator.localhost
  Quizlet              https://quizlet.api-emulator.localhost
  Ramp                 https://ramp.api-emulator.localhost
  Reddit               https://reddit.api-emulator.localhost
  Reducto              https://reducto.api-emulator.localhost
  Rent a Human         https://rentahuman.api-emulator.localhost
  Replit               https://replit.api-emulator.localhost
  Resend               https://resend.api-emulator.localhost
  Retool               https://retool.api-emulator.localhost
  Rippling             https://rippling.api-emulator.localhost
  Robinhood            https://robinhood.api-emulator.localhost
  Salesforce           https://salesforce.api-emulator.localhost
  Samsara              https://samsara.api-emulator.localhost
  Schwab               https://schwab.api-emulator.localhost
  Sentry               https://sentry.api-emulator.localhost
  ServiceNow           https://servicenow.api-emulator.localhost
  Shazam               https://shazam.api-emulator.localhost
  ShipStation          https://shipstation.api-emulator.localhost
  Shopify              https://shopify.api-emulator.localhost
  Sierra               https://sierra.api-emulator.localhost
  Signal               https://signal-messaging.api-emulator.localhost
  Silurian             https://silurian.api-emulator.localhost
  SiriusXM             https://siriusxm.api-emulator.localhost
  Skyscanner           https://skyscanner.api-emulator.localhost
  Slack                https://slack.api-emulator.localhost
  Snap                 https://snap.api-emulator.localhost
  Snowflake            https://snowflake.api-emulator.localhost
  Sourcegraph          https://sourcegraph.api-emulator.localhost
  Spark                https://spark.api-emulator.localhost
  Spectrum             https://spectrum.api-emulator.localhost
  Spotify              https://spotify.api-emulator.localhost
  Stainless            https://stainless.api-emulator.localhost
  State Farm           https://statefarm.api-emulator.localhost
  Steam                https://steam.api-emulator.localhost
  Stripe               https://stripe.api-emulator.localhost
  Substack             https://substack.api-emulator.localhost
  Suno                 https://suno.api-emulator.localhost
  Supabase             https://supabase.api-emulator.localhost
  SurveyMonkey         https://surveymonkey.api-emulator.localhost
  Symbolab             https://symbolab.api-emulator.localhost
  Telegram             https://telegram.api-emulator.localhost
  TikTok               https://tiktok.api-emulator.localhost
  Together AI          https://togetherai.api-emulator.localhost
  TrueMed              https://truemed.api-emulator.localhost
  Profound             https://tryprofound.api-emulator.localhost
  TurboTax             https://turbotax.api-emulator.localhost
  Twilio               https://twilio.api-emulator.localhost
  Uber                 https://uber.api-emulator.localhost
  UiPath               https://uipath.api-emulator.localhost
  UnifyGTM             https://unifygtm.api-emulator.localhost
  Unity Ads            https://unity-ads.api-emulator.localhost
  Upstash              https://upstash.api-emulator.localhost
  USAA                 https://usaa.api-emulator.localhost
  Vercel               https://vercel.api-emulator.localhost
  WeatherKit           https://weatherkit.api-emulator.localhost
  WhatsApp             https://whatsapp.api-emulator.localhost
  Whoop                https://whoop.api-emulator.localhost
  Wikipedia            https://wikipedia.api-emulator.localhost
  Wolfram              https://wolfram.api-emulator.localhost
  Workato              https://workato.api-emulator.localhost
  Workday              https://workday.api-emulator.localhost
  X                    https://x.api-emulator.localhost
  Xbox                 https://xbox.api-emulator.localhost
  Yahoo Finance        https://yahoo-finance.api-emulator.localhost
  YouTube              https://youtube.api-emulator.localhost
  YouTube Music        https://youtube-music.api-emulator.localhost
  Zapier               https://zapier.api-emulator.localhost

Move integration failures earlier

Write against real surfaces

REST, OAuth, SDK-compatible routes, SQL workflows, queues, webhooks, object storage, and provider-shaped errors.

Run against stateful clones

Create a GitHub repo, push commits, send mail, charge a card, mutate rows, then reset cleanly between scenarios.

Cover API and database paths

Test Postgres, MySQL, SQLite, DuckDB, warehouse, and lakehouse workflows without Docker or cloud accounts.

Fail in CI before production

Catch bad agent actions, SDK regressions, auth bugs, and schema assumptions before they reach users.

Point your SDK at localhost

Your existing code stays the same. Just change the host.

Before
const stripe = new Stripe(
  process.env.STRIPE_SECRET_KEY
)

// needs network
// needs a test-mode account
// rate-limited
With api-emulator
const stripe = new Stripe("anything")
stripe.config.host = "localhost"
stripe.config.port = 4010
stripe.config.protocol = "http"

// offline, instant, stateful

Use it your way

CLI

Run alongside your dev server. Pick which services you need.

npx -p api-emulator api --service github,stripe
Programmatic API

Import into Vitest or Jest. Start per-suite, reset or replay fixtures between tests.

import { createEmulator } from "api-emulator"

const github = await createEmulator({ service: "github", port: 4001 })
afterEach(() => github.reset())
afterAll(() => github.close())
Next.js adapter

Embed in your app. Same origin, no CORS issues, works on Vercel preview deployments.

npm install @api-emulator/adapter-next @api-emulator/core