What I built (in one paragraph)

verify-action-mcp is a small third-party HTTP service. You POST a (claim, evidence) pair from an AI agent, you get back a verdict and an HMAC-attested receipt. Cross-vendor (MCP-compatible — Claude Code, Cursor, Cline, Codex pick it up as a tool). Pure Python stdlib, no pip install, MIT-licensed. Live at verify.armadalab.dev .

The pattern it catches

If you've built anything with an AI agent harness, you've seen this:

"I deleted user 12345" — but the row count didn't change.

"I added a null check" — but the diff also rewrote 5 unrelated functions.

"I sent the welcome email to [email protected] " — but the request body actually targeted [email protected] .

These silent successes don't show up in benchmarks (which score "did the model say it succeeded?" ).…