Rewrites

Translate the request path before forwarding to the upstream.

routes:
  - match:
      paths: ["/api/*"]
    upstream: http://api:8000
    rewrite:
      strip_prefix: /api

Three options. They can be combined; path overrides the others.

strip_prefix

Removes a leading prefix.

Incoming	After strip_prefix: /api
/api/users	/users
/api/v1/orders	/v1/orders

add_prefix

Prepends a prefix.

Incoming	After add_prefix: /v1
/users	/v1/users

Combine with strip_prefix to swap prefixes:

rewrite:
  strip_prefix: /api
  add_prefix: /v1

Incoming	Forwarded
/api/users	/v1/users

path

Replaces the entire path. Wins over strip_prefix and add_prefix.

rewrite:
  path: /healthcheck

Incoming	Forwarded
anything	/healthcheck

OpenAPI runs after rewrite

OpenAPI validation checks the rewritten path, so your spec should describe the upstream's URL space, not the public one.