Use at your own risk. Mockingbird is under active development — APIs, behavior and package names may change without notice.

Mockingbird is a catalog of stateful test doubles for third-party HTTP APIs and SQL databases. Each one speaks the vendor's real surface, keeps state, and runs in-process.

Quick start

npm install -D @crvouga/mockingbird-service-stripe

import { createRuntime } from "@crvouga/mockingbird-service-stripe"

const stripe = createRuntime()

const res = await stripe.fetch(
  new Request("https://api.stripe.com/v1/customers", {
    method: "POST",
    headers: {
      authorization: "Bearer sk_test_mockingbird",
      "content-type": "application/x-www-form-urlencoded",
    },
    body: "email=ada@example.com",
  }),
)

console.log(res.status) // 200
const customer = await res.json() // { id: "cus_…", object: "customer", email: "ada@example.com", … }

// State persists: the customer is there when you list customers.
const list = await stripe.fetch(
  new Request("https://api.stripe.com/v1/customers", {
    headers: { authorization: "Bearer sk_test_mockingbird" },
  }),
)
console.log((await list.json()).data[0].id === customer.id) // true

Every package is self-contained ESM with TypeScript types, for Node >= 22 or Bun >= 1.2. To browse every service with a live, in-browser playground, run the docs site: bun docs.

Why Mockingbird

• The vendor's real surface. Each mock answers the provider's own paths, headers, status codes and error envelopes through fetch(Request) → Response. Point the official SDK at it.
• State that behaves. Records persist in an in-memory SQL engine. Created customers can be listed, orders move through their lifecycle, webhooks fire, and reset or snapshot takes one call.
• Checked against the real thing. Random walks generated from each vendored OpenAPI contract run against two mock instances in CI, and against the live sandbox when credentials exist.
• No network, no waiting. Everything runs in your test process. No sandbox keys, rate limits, shared test accounts or flaky round trips.
• Runs anywhere JavaScript runs. Most mocks are portable: Node, Bun, browsers and Workers. The docs site's playgrounds run the published packages in your browser tab.
• One contract for every service. Every HTTP mock shares /health, /__admin reset, snapshots, clock control, fault injection, request journals and per-namespace isolation.

The full rationale, and when not to use it: docs/WHY.md.

Services

52 services, each its own npm package. Every service declares a release tier:

• Ready (7): Complete, checked against the vendor, and kept stable. Use it in your test suite.
• Work in progress (45): Usable, but incomplete: operations, response shapes and options can still change between releases. Pin an exact version.

Ready

Service	Category	Package	What it mocks
Flex	Payments	@crvouga/mockingbird-service-flex	Stateful mock of the Flex HSA/FSA payments API: products (recorded catalog corpus), checkout sessions in payment, subscription, off-session and setup modes, subscriptions, customers, setup intents, refunds, the hosted checkout page, and Svix-signed webhooks.
Junction	Health & labs	@crvouga/mockingbird-service-junction	Stateful mock of the Junction (Vital) user API driven by its OpenAPI contract and verified by differential property tests against the Junction sandbox.
Medplum	Health & labs	@crvouga/mockingbird-service-medplum	Stateful, portable mock of the self-hosted Medplum server (FHIR R4 REST, OAuth2 and admin API) that runs anywhere JavaScript runs, proven at parity with a real self-hosted Medplum used as the oracle.
OAuth & Social Login	Identity	@crvouga/mockingbird-service-oauth	Portable social-login mock with Google, Apple, Microsoft, GitHub and generic OIDC profiles, private relay identities, reproducible edge cases, signed tokens and an accessible UI.
PostgreSQL	Databases	@crvouga/mockingbird-service-postgres	Pure TypeScript in-memory PostgreSQL implementation with zero WASM/native dependencies
SQLite	Databases	@crvouga/mockingbird-service-sqlite	Pure TypeScript in-memory SQLite implementation with zero WASM/native dependencies
Stripe	Payments	@crvouga/mockingbird-service-stripe	Stateful mock of the Stripe API (accounts by key, customers, payments, subscriptions with renewals, invoices, checkout with a hosted page, a Stripe.js stand-in, signed webhooks) at API versions 2024-06-20 and 2025-02-24.acacia, verified by differential property tests against Stripe test mode.

Work in progress

Service	Category	Package	What it mocks
Amazon Textract	AI & speech	@crvouga/mockingbird-service-textract	Stateful Amazon Textract mock with document analysis jobs, graph blocks, pagination, and deterministic notifications.
AWS Bedrock	AI & speech	@crvouga/mockingbird-service-bedrock	Stateful, scriptable mock of AWS Bedrock Runtime (Converse, ConverseStream, InvokeModel incl. Titan embeddings, Nova Sonic bidirectional streams over h2c) and AgentCore InvokeHarness, with exact event-stream framing.
AWS Polly & Transcribe	AI & speech	@crvouga/mockingbird-service-aws-speech	Stateful mock of AWS Polly (SynthesizeSpeech, StartSpeechSynthesisStream) and Transcribe (streaming over h2c, batch jobs), with exact event-stream framing and scripted transcripts.
LlamaCloud	AI & speech	@crvouga/mockingbird-service-llamacloud	Stateful mock of the LlamaCloud platform API: project and pipeline lookup, pipeline documents, and deterministic (scripted or term-overlap) retrieval, verified against the official llama_cloud_services SDK.
Amazon SQS	Communication	@crvouga/mockingbird-service-sqs	Stateful Amazon SQS mock with visibility, FIFO ordering, deduplication, batches, and redrive.
AWS Elemental MediaConvert	Communication	@crvouga/mockingbird-service-mediaconvert	Stateful AWS Elemental MediaConvert mock with endpoint discovery, async jobs, EventBridge events, and deterministic S3 outputs.
Daily	Communication	@crvouga/mockingbird-service-daily	Stateful mock of the Daily.co REST API: rooms, presence, eject, meeting tokens (minted and self-signed HS256, verified and decodable), and transcription/recording webhooks with transcripts written to S3.
Intercom	Communication	@crvouga/mockingbird-service-intercom	Stateful mock of the Intercom REST API 2.11: contacts (search, create with 409 on duplicates, update, get), conversations (create with Idempotency-Key, reply as JSON or multipart, close/open, get, cursor search), admins, and X-Hub-Signature-signed admin reply/close/open webhooks.
LiveKit	Communication	@crvouga/mockingbird-service-livekit	Stateful LiveKit mock with Twirp room APIs, JWT grants, participants, data, SIP/egress controls, and signed webhooks.
Mailosaur	Communication	@crvouga/mockingbird-service-mailosaur	Stateful mock of the Mailosaur email/SMS testing API (messages search, get, delete, long-poll) with an HTTP ingest so other mocks can drop mail in (Mockingbird service contract).
Resend	Communication	@crvouga/mockingbird-service-resend	Stateful mock of the Resend email API (send with idempotency, received emails, attachments) with an outbox and Svix-signed inbound webhooks (Mockingbird service contract).
Slack	Communication	@crvouga/mockingbird-service-slack	Stateful mock of Slack incoming webhooks and the Web API (chat.postMessage and friends) with an outbox of every alert the app sent.
Twilio	Communication	@crvouga/mockingbird-service-twilio	Stateful mock of Twilio Verify, Lookup v2, Messaging and Recordings on one port, with signed inbound SMS and voice webhooks (Mockingbird service contract).
Amazon DynamoDB	Databases	@crvouga/mockingbird-service-dynamodb	Stateful Amazon DynamoDB mock with typed items, expressions, indexes, pagination, transactions, and streams.
AHA	Health & labs	@crvouga/mockingbird-service-aha	Stateful AHA phlebotomy mock with signed HTTP orders, status webhooks, and a real deterministic SSH/SFTP result server.
CareTalk	Health & labs	@crvouga/mockingbird-service-caretalk	Stateful mock of CareTalk's external API: client-login tokens, GetForm definitions, SavePatientForm rounds, patient search/insert, states, free slots and appointments.
Edamam	Health & labs	@crvouga/mockingbird-service-edamam	Stateful mock of the Edamam APIs our apps call: food-database parser, nutrients and image analysis, nutrition analysis, recipe search v2, meal-planner select and shopping lists, over a built-in food and recipe corpus.
Fullscript	Health & labs	@crvouga/mockingbird-service-fullscript	Stateful mock of the Fullscript lab-ordering API: per-practitioner OAuth, clinic, session grants, forward-only lab orders with results, lab-order events, expiring result PDFs, and Fullscript-Signature webhooks.
Gene by Gene	Health & labs	@crvouga/mockingbird-service-genebygene	Stateful mock of Gene by Gene's Nucleus API v2 and auth host: tokens with credential blocking, catalog, shipping quotes, orders, kits, demographics, three-layer cancel, results with presigned downloads and S3 writes, subscriptions, and GxG-signed webhooks.
Healthie	Health & labs	@crvouga/mockingbird-service-healthie	Stateful mock of the Healthie GraphQL API (legacy surface): signIn, users, currentUser, updateUser/updateClient (incl. multipart avatar), locations, documents and folders with served downloads, form answers, offerings, billing items, and the IP-allowlisted status webhooks.
Makor CPG	Health & labs	@crvouga/mockingbird-service-makor-cpg	Stateful mock of the legacy Makor AI (CPG) API: care plans, plus-user, bloodwork webhook, subscriptions, Wholescripts orders, AI patient summaries and async-review scripts (processing → complete on the mock clock), with permissive CORS for browser-direct calls.
Optimal DX	Health & labs	@crvouga/mockingbird-service-odx	Stateful mock of the (retired) Optimal DX partner API: patients, partner links, HL7 and structured lab imports, Functional Health Reports (JSON/PDF), webhook registrations, and signed PatientTest webhooks.
Prism Labs	Health & labs	@crvouga/mockingbird-service-prism	Stateful mock of the Prism Labs body-scan API: subjects, scans, presigned capture upload, processing stages to READY, and deterministic body-composition, measurement, health-report and asset results.
Amazon Cognito	Identity	@crvouga/mockingbird-service-cognito	Stateful Amazon Cognito User Pools mock for AWS SDK and browser authentication tests.
AWS Secrets Manager & SSM	Identity	@crvouga/mockingbird-service-aws-secrets	Stateful AWS Secrets Manager and SSM Parameter Store mock with versions, stages, rotation, and redacted controls.
Persona	Identity	@crvouga/mockingbird-service-persona	Stateful mock of the Persona identity-verification API: inquiry create, list (reusable lookup), get, a hosted flow page, admin lifecycle transitions, and Persona-Signature webhooks.
EasyPost	Maps & logistics	@crvouga/mockingbird-service-easypost	Stateful mock of the EasyPost trackers API: create/re-use trackers, EasyPost's test tracking codes, admin status transitions and EasyPost's error envelope.
Google Maps	Maps & logistics	@crvouga/mockingbird-service-google-maps	Mock of Google Places Autocomplete / Details / Find Place, the Geocoding API and a Maps JavaScript (places) shim, over a QA address corpus, with Google's status codes and fault presets.
Customer.io	Marketing	@crvouga/mockingbird-service-customerio	Stateful mock of Customer.io: Segment-compatible CDP (identify/track/batch, SDK drop-in), App API transactional email/SMS/inbox sends with an outbox, message catalog, link-click tracking, and signed reporting webhooks.
FirstPromoter	Marketing	@crvouga/mockingbird-service-firstpromoter	Stateful mock of the FirstPromoter v2 API: promoters (adopt-before-create by cust_id), signup tracking by tid / promoter_id / ref token, iframe login, archive, and Basic-auth lead_becomes_referral webhooks.
Klaviyo	Marketing	@crvouga/mockingbird-service-klaviyo	Stateful mock of the Klaviyo events API: JSON:API event create (Ordered Product, Placed Order), event reads, unique_id dedupe, JSON:API errors and an outbox.
OpenTelemetry	Observability	@crvouga/mockingbird-service-otel	Stateful mock of an OTLP/HTTP collector (JSON and protobuf traces and logs) and the OpenObserve search API over the same store.
PostHog	Observability	@crvouga/mockingbird-service-posthog	Stateful mock of PostHog: /flags v2 and legacy /decide evaluation with per-test flag, variant and payload control, remote config, gzip/base64 capture (/batch/, /e/, /i/v0/e/), recordings intake, and the feature-flag management and HogQL API slice.
Kill Bill	Payments	@crvouga/mockingbird-service-kill-bill	Stateful Kill Bill billing mock with accounts, subscriptions, invoices, payments, credits, retries, catalog, and clock controls.
Pharmetika	Pharmacy	@crvouga/mockingbird-service-pharmetika	Stateful mock of the Pharmetika compounding-pharmacy provider portal: clinics, patients, medication-order validate / EPCS prepare / submit / lookup, the v7 cancel, the medication-template catalog, and status webhooks.
Portal Agent	Pharmacy	@crvouga/mockingbird-service-portal-agent	Stateful mock of our eRx portal agent (LifeFile/VPI browser runner): the fulfilment job endpoint with strict response rules, a job store, fault presets, and x-internal-key callbacks.
RxVortex	Pharmacy	@crvouga/mockingbird-service-rxvortex	Stateful mock of the RxVortex (Strive) pharmacy API: OAuth token, order submit, status, cancel, recovery by sender order id, preset catalog, and signed status webhooks.
VPI	Pharmacy	@crvouga/mockingbird-service-vpi	Stateful mock of the VPI compounding pharmacy API: JWT authentication, products, clinic, patients, providers, saveNewPrescription drafts and the three paged prescription status lists.
Wholescripts	Pharmacy	@crvouga/mockingbird-service-wholescripts	Stateful mock of the Wholescripts supplement fulfilment API: product and private-label catalogs, order submit, status polling and cancel, with admin status transitions.
AWS Step Functions	Productivity	@crvouga/mockingbird-service-step-functions	Stateful AWS Step Functions mock with idempotent executions, callbacks, deterministic transitions, and history.
Formbricks	Productivity	@crvouga/mockingbird-service-formbricks	Stateful mock of Formbricks (Geviti fork): client environment state seeded from our production survey clone, response creation with the fork's validation errors, the v1 management API, the widget script, and responseFinished webhooks.
Google Calendar	Productivity	@crvouga/mockingbird-service-google-calendar	Stateful mock of the Google Calendar v3 API and Google OAuth our EMR calls: events list/insert/update/delete/watch, channels.stop, calendarList/calendars, token exchange/refresh/revoke and userinfo, with signed-by-header push notifications.
Payload CMS	Productivity	@crvouga/mockingbird-service-payload-cms	Stateful mock of the Payload CMS collection REST API: paginated finds with a where-query subset, find by id, a seeded marketing collection and admin-editable documents.
Plane	Productivity	@crvouga/mockingbird-service-plane	Stateful mock of the Plane REST API v1: cursor-paginated work items, comments, links, states and labels, with Plane's rate limit and error shapes.
Amazon S3	Storage	@crvouga/mockingbird-service-s3	Stateful Amazon S3 mock with binary objects, listing, copies, multipart uploads, presigned URLs, and canonical XML errors.

Operation coverage per service is in each package's SUPPORT.md (or COMPATIBILITY.md for the SQL engines), and on the docs site's coverage page.

One contract for every HTTP service

Every HTTP service ships an in-process fetch, a Node server and a CLI, and all answer the same control surface, so a stack learns it once.

npx mockingbird-junction serve --port 8787                # one service
npx mockingbird-junction serve --config mockingbird.json  # every service in the config

Surface	What it gives you
createRuntime() · createServer() (./server) · mockingbird-<service> serve	The mock as one runtime-neutral fetch, or a listening server from Node or the CLI
GET /health	Unauthenticated readiness probe, outside the vendor's auth gate
/__admin/* (x-mockingbird-admin-key optional)	Reset, snapshot and restore, clock control, fault injection, a request journal, metrics with unmatched-route counts, plus service-specific routes
x-mockingbird-namespace	Per-request isolation: parallel workers share one process without sharing data
--seed, clock control	Seeded randomness and an injectable clock, so a run replays exactly
--log json	One structured line per request: operation id, status, duration, namespace, fault

{
  "services": {
    "junction": { "port": 8787, "options": { "corpus": "./test/junction-corpus.json" } },
    "stripe": { "port": 12111 }
  }
}

mockingbird.json names services by their package suffix and takes each one's serve flags; any installed service's CLI can serve all of them. The database engines are not HTTP APIs, so they are outside this contract.

For coding agents

Every service README doubles as its integration guide and ships inside the npm tarball (node_modules/<package>/README.md). llms.txt indexes them by tier, and the docs site publishes the same content as markdown and JSON, rebuilt from the packages on every build. When a mock diverges from the real API, lacks a feature you call, or the vendor you need is not in the catalog, file an issue: the filing guide gives the title format, templates and the behavior spec for feature and service requests.

Contributing

git clone https://github.com/crvouga/mockingbird.git && cd mockingbird
bun run setup   # install, build every package, create .env.local
bun test

Building, testing and bun run check need no secrets and no accounts. Live parity against the real provider sandboxes runs on GitHub Actions with the repo's secrets, so anyone with write access runs it without holding a key: bun run parity:remote -- <service>. See docs/DEVELOPMENT.md and docs/SECRETS.md.

Guides

Guide
Why Mockingbird	Your tests are only as honest as the fakes they run against. Most suites that touch Stripe, Twilio or a lab partner either call a shared sandbox or stub the client. Both fail in ways that are expensive to notice. Mockingbird is a third option.
Testing and parity	How every mock is proven to behave like its vendor: differential contracts, property-based walks, and live parity against real sandboxes.
Authoring a Mockingbird service	How to add a vendor mock to this repo. The reference implementation is packages/service/rxvortex: copy its layout and patterns.
Service catalog coverage	Where each section of the geviti "Mockingbird wish list — service catalog" (2026-09-20) lives in this repo, how it is proven, and what the proof turned up. Every package follows AUTHORING_A_SERVICE.md and ships the same evidence:
Developing Mockingbird	Working on this repo: requirements, how the packages are layered, and the quality gates every change passes.
Reporting issues	How coding agents in other projects file a GitHub issue when a mock diverges from its oracle, lacks a feature they call, or breaks, or when they need a service mocked that the catalog does not have yet. Agents in this repository pick the issues up and resolve them.
Releasing	How packages get from main to npm. Once the NPM_TOKEN repo secret is set, releases run automatically.
Secrets runbook	Where every credential lives, who needs it, and how to run live parity without ever holding a sandbox key: GitHub Actions repo secrets are the only secret store.

License

MIT.