# Clerk Emulator (service host)

Create an instance:
curl -s -X POST https://clerk.emulators.dev/_emulate/instances
# Hosted deployments create instances lazily when the returned URL is first used. The instance URL is a capability: anyone who has it can read and modify the instance, so save the returned URLs. Never store real secrets in an emulator.
# The server generates an unguessable name. An optional {"instance":"<prefix>"} body adds a readable prefix.

Then use the returned providerBaseUrl / controlBaseUrl. Example below uses a sample instance.
# Clerk Emulator

Stateful Clerk emulator for the Backend API, OAuth and OIDC sign-in, JWKS, sessions, and organization management.

Provider base URL: https://clerk.your-instance.emulators.dev
Control base URL: https://clerk.your-instance.emulators.dev/_emulate

Supported surfaces:
- Backend API: partial at /v1
- OAuth and OIDC: supported at /oauth
- OpenID Connect: supported at /.well-known

Control endpoints:
- https://clerk.your-instance.emulators.dev/_emulate/manifest
- https://clerk.your-instance.emulators.dev/_emulate/coverage
- https://clerk.your-instance.emulators.dev/_emulate/connections
- https://clerk.your-instance.emulators.dev/_emulate/state
- https://clerk.your-instance.emulators.dev/_emulate/ledger
- https://clerk.your-instance.emulators.dev/_emulate/faults
- POST https://clerk.your-instance.emulators.dev/_emulate/credentials
- POST https://clerk.your-instance.emulators.dev/_emulate/seed
- POST https://clerk.your-instance.emulators.dev/_emulate/reset

Fault injection:
Arm a one-shot provider failure with a glob pathPattern, then inspect /ledger for faulted: true.
curl -s -X POST https://clerk.your-instance.emulators.dev/_emulate/faults \
  -H "content-type: application/json" \
  -d '{"match":{"method":"GET","pathPattern":"/v1/*"},"response":{"status":503,"body":{"error":"temporary"}}}'

Connect:

## Clerk Backend SDK (TypeScript)
import { createClerkClient } from "@clerk/backend";

const clerk = createClerkClient({
  secretKey: "<token>",
  apiUrl: "https://clerk.your-instance.emulators.dev",
});

const users = await clerk.users.getUserList();

## Clerk environment (env)
CLERK_API_URL=https://clerk.your-instance.emulators.dev
CLERK_SECRET_KEY=<token>

## curl
curl -s https://clerk.your-instance.emulators.dev/v1/users -H "authorization: Bearer <token>"

## Base URL (env)
CLERK_BASE_URL=https://clerk.your-instance.emulators.dev

## Create a credential
curl -s -X POST https://clerk.your-instance.emulators.dev/_emulate/credentials \
  -H "content-type: application/json" \
  -d '{"type":"api-key"}'

## Inspect requests
curl -s https://clerk.your-instance.emulators.dev/_emulate/ledger