Open an operation
Choose the endpoint in API Designer.
// Mock Responses
Model the responses your frontend must handle.
Configure success and failure variants, then call enabled mocks through the authenticated hosted runtime while the backend is still being built.
Payments API / mocks / example preview
Response variants
+ AddDefined on POST /payments
Payment created
201Delay 120 ms
Card declined
422Delay 300 ms
Service unavailable
503Delay 1,000 ms
Exercise a declined payment without a live payment backend
Save and enable a Card declined variant on POST /payments with status 422 and the body below. Configuration alone sends no request. Execute it using the workspace mock base URL and a mock server key; hosted calls consume the account quota. Keep the key out of public frontend bundles.
POST /api/public/v1/mock/<workspaceId>/payments
Authorization: Bearer <mock-server-key>
X-Rest-Test-Mock: Card declined
Expected configured response: 422
{ "code": "card_declined" }Capabilities
Mock Responses capabilities
- Define several named variants for one operation.
- Model success, validation, authorization and server errors.
- Set status code, headers, JSON body and response delay.
- Keep frontend expectations beside the endpoint contract.
Workflow
Your mock responses workflow
Add a variant
Create a named success or error response.
Define behavior
Set status, headers, body and optional delay.
Share the contract
Review variants with workspace members, then execute enabled mocks with a scoped workspace mock server key.
Built for real handoffs.
Parallel development
Define expected response shapes while backend implementation is still moving.
Error-state design
Give frontend work concrete authorization, validation and server errors to handle.
Contract review
Keep variant bodies and headers attached to the operation being discussed.
Related features
// FAQ
Questions, answered.
// GET STARTED
Bring your API workflow into one workspace.
Start with an OpenAPI or Swagger JSON definition and keep the workflow together.