12-observability.yaml

# Observability: Prometheus metrics, OTLP traces, session recording, and
# semantic tool filtering.

listen: 127.0.0.1:8000

inbound:
  mode: anonymous

backends:
  everything:
    transport: stdio
    command: ["npx", "-y", "@modelcontextprotocol/server-everything"]

telemetry:
  # Exposes GET /metrics:
  #   mcpproxy_messages_total{direction,backend,method,tool,decision}
  #   mcpproxy_message_duration_seconds{direction,backend,method}
  #   mcpproxy_sessions_active
  prometheus_path: /metrics
  # OTLP gRPC trace export (e.g. an otel-collector or Jaeger):
  otlp_endpoint: 127.0.0.1:4317
  service_name: mcpproxyd

# Session recording: one append-only JSONL file per session holding each
# audit event (tool_call, tool_denied, tools_changed, approval_*, …).
# Replay:  jq -r '[.time,.event,.tool//""] | @tsv' sessions/<sid>.jsonl
wal_dir: ./sessions

# Semantic tool filtering: tools/list returns only the top_k tools most
# relevant to `purpose` (lexical scorer; plug in an embedding scorer when
# embedding the gateway). A smaller tool catalog costs fewer tokens per
# request.
optimizer:
  top_k: 8
  purpose: "read files and search documentation"