Direct Response

FastGateway can return static responses directly without forwarding to backends.

Basic Direct Response

Return a simple response:

filters:
  - type: "DirectResponse"
    directResponse:
      statusCode: 200
      body: "OK"

Health Check Endpoint

Create a health check endpoint:

matches:
  - path:
      type: "Exact"
      value: "/health"
filters:
  - type: "DirectResponse"
    directResponse:
      statusCode: 200
      body: '{"status": "healthy"}'

Maintenance Page

Return a maintenance response:

filters:
  - type: "DirectResponse"
    directResponse:
      statusCode: 503
      body: '{"error": "Service temporarily unavailable for maintenance"}'

Custom Error Pages

Block specific paths with custom responses:

matches:
  - path:
      type: "Prefix"
      value: "/admin"
filters:
  - type: "DirectResponse"
    directResponse:
      statusCode: 403
      body: '{"error": "Forbidden"}'

Use Cases

Scenario	Status Code
Health checks	200
Readiness probes	200
Maintenance mode	503
Blocked paths	403
Not found pages	404

Notes

• No backend is contacted when DirectResponse is used
• Combine with header modification for proper Content-Type
• Useful for synthetic endpoints that don't need backend logic