# PlanetScale Emulator (service host)

Create an instance:
curl -s -X POST https://planetscale.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.
# PlanetScale Emulator

Stateful PlanetScale emulator: the Doorkeeper OAuth authorization server with Dynamic Client Registration, PKCE, and literal HTTP Basic client authentication, plus the hosted MCP server at /mcp/planetscale with read-only organization, database, and branch tools over seeded state.

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

Supported surfaces:
- PlanetScale OAuth (Doorkeeper): partial at /oauth
- PlanetScale MCP server: partial at /mcp/planetscale
- OAuth consent page: supported at /oauth/authorize

Control endpoints:
- https://planetscale.your-instance.emulators.dev/_emulate/manifest
- https://planetscale.your-instance.emulators.dev/_emulate/coverage
- https://planetscale.your-instance.emulators.dev/_emulate/connections
- https://planetscale.your-instance.emulators.dev/_emulate/state
- https://planetscale.your-instance.emulators.dev/_emulate/ledger
- https://planetscale.your-instance.emulators.dev/_emulate/faults
- POST https://planetscale.your-instance.emulators.dev/_emulate/credentials
- POST https://planetscale.your-instance.emulators.dev/_emulate/seed
- POST https://planetscale.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://planetscale.your-instance.emulators.dev/_emulate/faults \
  -H "content-type: application/json" \
  -d '{"match":{"method":"GET","pathPattern":"/v1/*"},"response":{"status":503,"body":{"error":"temporary"}}}'

Connect:

## MCP endpoint
https://planetscale.your-instance.emulators.dev/mcp/planetscale

## Register a client
curl -X POST https://planetscale.your-instance.emulators.dev/oauth/registration \
  -H 'content-type: application/json' \
  -d '{"client_name":"My app","redirect_uris":["http://localhost:3000/callback"]}'

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

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

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