CapCard is the open standard for machine-readable, verifiable capability claims. A single JSON file your project publishes so agents — and humans — know exactly what you've proven, measured, and reproduced.
The agent economy has inverted the discovery funnel. An AI agent researching tools doesn't read landing pages. It queries structured data, verifies claims, and reports back. If your project doesn't have a CapCard, the agent guesses — and guesses wrong.
Three layers, each independently useful. Start at layer one — you're done in an afternoon.
Drop a single JSON file at your repo root. Declare capabilities with honest status labels, benchmarks with reproducible commands, and proofs with verification dates. The schema enforces structure; you control the claims.
capcard verify validates your card against the schema, parses every reproducibility command, and returns a structured JSON report. Runs offline. No account needed. No data leaves your machine.
The hosted verification service re-runs your benchmarks in a clean-room container, issues a signed trust score, and attaches a CapCard Certified badge to your commit. Agents query the registry. Humans see the badge.
Monogate is an open-source mathematics library built around a single binary operator eml(x,y) = exp(x) − ln(y). It carries the most rigorous CapCard we know of — not because we wrote both, but because the results earned it.
A CapCard doesn't require certainty — it requires honesty. proven means proven. conjecture means conjecture. Agents and humans can handle nuance. What breaks trust is false precision.
{ "valid": true, "card_name": "Monogate", "version": "0.7.0", "capabilities_count": 17, "benchmarks_count": 22, "proofs_count": 11, "trust_score": 0.94, "errors": [] }
Verify any CapCard locally. The CLI is open-source, runs offline, and exits 0 on valid.
A minimal required surface — five top-level fields — plus rich optional structure for capabilities, benchmarks, proofs, and trust scores. Start minimal, add rigor as your claims earn it.
{ "capcard_version": "1.0.0", "name": "your-project", "version": "1.0.0", "capabilities": [{ "id": "my.feature", "name": "My Feature", "status": "empirically_confirmed" }], "benchmarks": [] }
Add a capability_card.json to your project. It costs an afternoon. It pays back every time an agent — or a careful human — needs to know what you've actually built.