The engine executes workflow programs and resolves real credentials, so we treat security reports with urgency.

Please do not open a public issue for a security vulnerability.

• Preferred: use GitHub's private vulnerability reporting ("Report a vulnerability" under the Security tab of this repository).
• Or email security@boardwalk.sh.

Include what you found, a reproduction, and the impact you believe it has. You'll get an acknowledgement within 72 hours and a status update at least weekly until resolution.

• Secret values must never appear in logs, run-event streams, error messages, or agent() context (the secrets invariant — exercised by the conformance suite). Anything that makes them do so is a vulnerability — report it.
• A workflow program is the operator's own trusted code, run in a per-run working directory. Reports should concern the engine's boundaries (secret handling, redaction, run isolation, the MCP token store, the SDK-resolution symlink), not what a program can do to its own workspace.
• Self-hosting runs on your own hardware with your own keys; deployment hardening of the box the engine runs on is the operator's responsibility.