Pro Feature

Dynamic Responses

Go beyond static JSON. Return different responses based on request headers, body values, query params, or even random conditions — making your mocks feel truly alive.

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What you can build

Powerful conditional logic without writing a single line of server code

Header-based routing

Return a 401 when the Authorization header is missing. Return different user profiles based on an X-User-ID header.

Body-driven conditions

Parse the request body and return a 422 with validation errors if required fields are missing.

Random scenarios

Simulate flaky APIs by configuring a 20% chance of returning a 500 error — great for resilience testing.

Query param filters

Return paginated data based on ?page= and ?limit= params. Return filtered results based on ?status=active.

Template syntax

Use simple Mustache-style placeholders to inject request data directly into your response body. No extra tools needed.

{{request.body.name ?>'}} — inject from request body
{{request.header.X-User-Id ?>'}} — inject from headers
{{request.query.page ?>'}} — inject from query string
{{fake.uuid ?>'}} — random UUID
{{fake.name ?>'}} — random person name

{
  "id": "{{fake.uuid ?>' }}",
  "name": "{{request.body.name ?>' }}",
  "email": "{{request.body.email ?>' }}",
  "created_at": "{{fake.datetime ?>' }}",
  "status": "active"
}