# Security Notes
## Current controls
- Confirmation token required for write tools:
- `auditlens.create_issue`
- `sitelint.export_report`
- `releasebutler.create_release`
- Policy checks for repositories and URLs.
- In-memory rate limiting for write/scan surfaces.
- Immutable receipt and audit references.
- Immutable object content addressing:
- local refs use `sha256` file names
- S3 refs use `s3://<bucket>/<prefix>/<sha256>...`
- Dual-read, S3-write strategy prevents legacy reference breakage during backend cutover.
- Structured logs include operation metadata with request IDs.
## Recommended hardening for internet-facing deployment
- Put `/mcp` behind reverse proxy TLS.
- Enable API key mode (`MCP_AUTH_MODE=api_key`) or mTLS.
- Restrict allowed outbound network destinations at host/firewall layer.
- Run with least privilege filesystem permissions on `data/`.
- Add external SIEM shipping for audit logs.
## Telemetry data sensitivity
- Logs:
- avoid logging secrets, PATs, private keys, or full tokenized payloads.
- keep to request metadata, tool names, status, and latency.
- Metrics:
- keep labels low-cardinality (`tool`, `status`, `bucket`) to prevent cardinality abuse.
- Traces:
- OTLP export may carry URL and API path metadata; route to trusted collectors only.
- treat trace storage as operationally sensitive data.
