agent-receipts/obsigna

brew install agent-receipts/tap/obsigna
obsigna daemon start
For Go: go get obsigna.dev/sdk/go
For TypeScript: npm install @obsigna/sdk-ts
For Python: pip install obsigna

Usage

• •Add PostToolUse hook to ~/.claude/settings.json
• •Inspect audit trail with obsigna list/show/verify
• •Use the MCP proxy to wrap any MCP server

Key features

• ✓Cryptographically signed audit trails
• ✓MCP stdio proxy signing every tool call
• ✓Policy hooks and risk scoring
• ✓Go/TypeScript/Python SDKs
• ✓Formal verification of the receipt chain

Best for

Teams that need tamper-evident audit trails for AI agent actions

Caveats

• ⚠Requires the daemon to hold the signing key and own the audit chain
• ⚠In-process trust model allows forgery by anyone with code execution