Policy Context

# Policy with context_headers and context_meta
#
# Demonstrates the host-supplied context surface: `context_headers`
# maps reserved-prefix HTTP headers to agent / framework extension
# fields so APL rules can reference them; `context_meta` stamps
# operator-defined scope, tags, and properties onto every policy
# evaluation.
#
# Headers under reserved prefixes (`x-praxis-*`, `x-ext-agent-*`,
# `x-ext-protocol-*`) are set by the gateway itself — ingress rejects
# client requests carrying them, so values here are trusted.
#
# Usage:
#   cargo run -p praxis-proxy -- \
#     -c examples/configs/security/policy-context.yaml
#
# The `context_meta.scope` value feeds the PPE's scoped route resolver,
# selecting authentication and authorization blocks that declare the
# matching `meta.scope:` in the policy document.

listeners:
  - name: default
    address: "127.0.0.1:8080"
    filter_chains:
      - main

filter_chains:
  - name: main
    filters:
      # A trusted filter (or ingress controller) populates the
      # reserved-prefix headers before the policy filter reads them.
      # In production these are injected by infrastructure; `headers`
      # with `request_set` simulates this for the example.
      - filter: headers
        request_set:
          # Calling agent identity, e.g. from an orchestrator sidecar.
          - name: x-ext-agent-id
            value: "planner-v2"
          # Conversation identifier assigned by the host.
          - name: x-ext-agent-conversation
            value: "conv-00000000-0000-0000-0000-000000000000"
          # Client framework reported by the protocol classifier.
          - name: x-ext-protocol-framework
            value: "langchain"

      - filter: policy
        config_path: /etc/praxis/policy.yaml
        require_protocol_metadata: true

        # Map reserved-prefix headers to extension fields.
        # Keys are typed: only agent.* and framework.* targets listed
        # in ContextField are accepted (agent.session_id is excluded —
        # it has dedicated handling via the session taint subsystem).
        context_headers:
          agent.agent_id: x-ext-agent-id
          agent.conversation_id: x-ext-agent-conversation
          framework.framework: x-ext-protocol-framework

        # Operator-defined metadata stamped onto every evaluation.
        context_meta:
          scope: production
          tags:
            - compliance
          properties:
            region: us-east-1

      - 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