Mirroring

Send copies of requests to alternative backends for shadow testing.

Attaches to: Route

Route

Backend

Note

Agentgateway supports more than one configuration style. Where a feature can also be configured in the simplified llm or mcp modes, the examples on this page show each option in tabs. For more information, see Routing-based configuration.

Request mirroring allows sending a copy of each request to an alternative backend. These requests will not be retried if they fail.

Simplified (MCP)Routing-based

# yaml-language-server: $schema=https://agentgateway.dev/schema/config
mcp:
  port: 3000
  policies:
    requestMirror:
      backend:
        host: localhost:8080
      # Mirror 50% of requests
      percentage: 0.5
  targets:
    - name: everything
      stdio:
        cmd: npx
        args: ['@modelcontextprotocol/server-everything']
yaml
# yaml-language-server: $schema=https://agentgateway.dev/schema/config
gateways:
  default:
    port: 3000
routes:
  - policies:
      requestMirror:
        backend:
          host: localhost:8080
        # Mirror 50% of requests
        percentage: 0.5
    backends:
      - host: localhost:8000