Cors

Spec-compliant CORS filter with preflight handling, origin validation, and credential support

Category: Setup-dependent integration
Task: Spec-compliant CORS filter with preflight handling, origin validation, and credential support

Prerequisites: The external service, credentials, or certificates referenced by this configuration.

Run it: Use ghcr.io/praxis-proxy/praxis:0.7.2 and follow the first reverse-proxy tutorial to mount and start the configuration.

This configuration comes from the selected release. The example has not been run here; external services are not bundled.

Download the source file.

# CORS (Cross-Origin Resource Sharing)
#
# Spec-compliant CORS filter with preflight handling,
# origin validation, and credential support.
#
# The CORS filter must run before filters that reject
# requests (e.g. ip_acl, guardrails) so that preflight
# OPTIONS are handled before those filters block them.
#
# allow_credentials enables Access-Control-Allow-Credentials: true.
# Per the Fetch spec, credentials require explicit origins (not
# wildcards) for allow_origins, allow_methods, and allow_headers.
#
listeners:
  - name: default
    address: "127.0.0.1:8080"
    filter_chains:
      - main

filter_chains:
  - name: main
    filters:
      - filter: cors
        allow_origins:
          - "https://app.example.com"
          - "https://*.example.com"
        allow_methods:
          - GET
          - POST
          - PUT
          - DELETE
        allow_headers:
          - Content-Type
          - Authorization
          - X-Request-ID
        expose_headers:
          - X-Request-ID
          - X-RateLimit-Remaining
        max_age: 3600
        allow_credentials: true

      - filter: router
        routes:
          - path_prefix: "/"
            cluster: backend

      - filter: load_balancer
        clusters:
          - name: backend
            endpoints:
              - "127.0.0.1:3000"

insecure_options:
  allow_private_endpoints: true # example proxies to local backends