Matching and filters

The first token in a rule selects the traffic to match. Use the narrowest pattern that still expresses your intent.

Common patterns

Text
# all requests to a domainapi.example.com host://localhost:3000# URL or path prefixhttps://api.example.com/v1/ host://localhost:3000# wildcard*.example.com resHeaders://x-environment=local# regular expression/^https:\/\/api\.example\.com\/v[12]\//i reqHeaders://x-debug=1# port:8080 reqDelay://100

PostGate supports domain, full-URL, path-prefix, exact, wildcard, regular-expression, scheme-free, and port patterns. Where negation is supported, prefix the pattern with ! to exclude matching traffic.

Inline filters

Filters narrow a matching pattern without changing its action:

Text
api.example.com filter://m:POST reqHeaders://x-write=1api.example.com filter://p:https resHeaders://strict-transport-security=api.example.com filter://port:443 reqHeaders://x-tls=1api.example.com filter://h:content-type=json resDelay://200api.example.com filter:///\/v2\//i reqHeaders://x-api-version=2

Supported filters include method, protocol, port, content type, header, host, client IP, include/exclude patterns, and response status.

Rule ordering

When several enabled rules match, PostGate collects the applicable actions in rule order. Avoid broad rules that unintentionally overlap more specific mocks or routes. Keep environment-wide headers and traffic controls in separate groups so they can be enabled or disabled independently.