Run it locally

Flight recorder for AI agents

Every tool call your agent makes, on the record.

An MCP proxy signs a hash-chained receipt for every call. Edit or cut one, and verification names the step.

Play back a real run Verify a pack
Drawing of an orange flight recorder labelled Agent Recorder, Do Not Edit. Its tape window shows 10 receipts with step 3 marked; its data plate reads session 933f87da, 10 of 10 receipts sealed.AGENT RECORDERDO NOT EDIT · NE PAS MODIFIERS/N 933F87DARCPT 10/10 SEALEDROOT C30BB904394A1234
Drawn from recorded session 933f87da: 10 receipts, sealed.

The agent talks. The tape keeps the receipts.

Signed by the proxy, not the agent, and chained so nothing can be quietly removed from the record.

Three steps from a tool call to a verdict.

  1. 01

    Record

    An MCP proxy signs a receipt for every tool call, chained to the one before.

  2. 02

    Seal

    The session is sealed under a Merkle root. The key stays outside the workspace.

  3. 03

    Verify

    Anyone checks the pack offline. An edit, reorder or cut names the step.

A real agent asked for .env. The tape caught it.

Receipts
10
Denied
1
Tests
91
See the evidence

What’s live today

Live

The offline verifier and both recorded runs’ packs, checked in your browser.

Setup required

Zetaris and Meterless need API keys. The GitLab Duo flow has not run yet.

Put it between your agent and its tools.

Point any MCP client at the proxy, or wrap an existing stdio MCP server.

pnpm --filter @blackbox/proxy start
node packages/proxy/dist/server.js --upstream "<stdio MCP server>"
pnpm dev   # dashboard at localhost:3000/recorder
Run the recorder locally Verify a pack