signed-audit-trails-recipe

SKILL.md

Signed Audit Trails for Claude Code Tool Calls

Cookbook-style walkthrough for cryptographically signed receipts on every
Claude Code tool call. This is the teaching skill. For the runtime
implementation, install the protect-mcp plugin.

What this gives you

Every tool call (Bash, Edit, Write, WebFetch) is:

Evaluated against a Cedar policy before execution. If the policy denies
the call, the tool does not run.

Signed as an Ed25519 receipt after execution. Receipts are
JCS-canonical, hash-chained, and verifiable offline by anyone with the
public key.

An auditor, regulator, or counterparty can verify the full chain later with a
single CLI command (npx @veritasacta/verify receipts/*.json). No network
call, no vendor lookup, no trust in the operator.