Metered upstreams
Models, payments, and maps bill every test call. The twin counts what you would have spent.
Stateful API simulation
A twin for every dependency your tests call.
OpenAI, payments, and services that are still being built. It remembers state, fails on purpose, and answers curl from the first minute.
/sim/demoGET /health
These buttons call the public twin at /sim/demo.
Services still in progress
An order created with POST is there on the next GET. Static JSON cannot do that.
Failure drills
Switch the whole dependency to Degraded or Outage and get latency, errors, and 503s on demand.
Ready to call
Stateful resources
One route covers list, create, read, update, and delete.
OpenAI compatible
chat/completions returns JSON, SSE, and tool_calls.
Scenarios
Normal, Degraded, and Outage. Latency, error rate, and RPM are configurable.
CI ready
API keys, curl, and a control API that flips the scenario from a pipeline.
From specs and logs
Paste OpenAPI JSON or one real response and get routes.
Log scrubbing
Emails, card numbers, and SSNs stay out of the request log.
Plans
Free
$0
- 3 twins
- 30 routes
- State, models, gRPC, WebSocket, Kafka
- 1 seat
Team
14-day trial
- 40 twins
- 400 routes
- 10 seats, editor or viewer
- OIDC SSO and Stripe billing
Enterprise
Talk to us
- Self-hosted
- 200 twins
- 50 seats
- Register interest on the Plan page
Protocols and the account
Traffic recording
Point a twin at an upstream. Calls are forwarded and stored, or POST a capture to /__tap and save it as a route.
gRPC, WebSocket, Kafka
Unary JSON RPCs, a socket on port 3001, and topics with offsets. The same twin URL serves all three.
SSO
Connect an OIDC issuer to an email domain. Those accounts join the workspace as viewers.
Billing
Subscribe to Team with Stripe. The webhook keeps the workspace on Team while the subscription is active.