XAIP Protocol
Behavioral trust scoring for MCP servers — open protocol, zero-auth API.
When an agent calls a service, a signed transaction proves the call was authorized. It does not prove the call was safe to make. XAIP is one attempt at that missing layer: dual-signed Ed25519 receipts per MCP tool call (hashes only — no raw content leaves your machine), aggregated into a live Bayesian trust score per server.
Every score below is computed from real receipts and is queryable without auth:
curl https://xaip-trust-api.kuma-github.workers.dev/v1/trust/context7trust — observed success probability for this server, based on signed execution receipts. Higher means the server has succeeded more often, across more independent callers, with fewer error patterns.
Live trust scores
| Server | Trust | Verdict | Receipts | Flags |
|---|---|---|---|---|
| fetching… | ||||
How these scores get used
The xaip-claude-hook fetches this API before every MCP tool call. If a server scores below the caution threshold, you see inline in Claude:
⚠ XAIP: "fetch" trust=0.38 (low_trust, 40 receipts)
Risk: high_error_rateAfter each call, the hook signs a receipt (hashes only — no raw content leaves your machine) and posts it to the aggregator. Next caller sees a slightly more accurate score.
For programmatic decision-making across candidate servers (e.g. "pick the highest-trust server that can handle task X"), that logic lives in a sibling project — Veridict — which consumes XAIP scores as one of its inputs. XAIP is the data layer; Veridict is the decision layer.
low_caller_diversity flag means one caller dominates the dataset — trust is uncertain because there aren't enough independent sources yet. Right now that caller is me, and closing that gap is exactly what installers are for. Error classification is heuristic; false positives possible.
How to contribute
The easiest way: install the Claude Code hook. Before each MCP tool call it fetches the score and warns inline if low; after each call it posts a signed receipt to the public aggregator.
npm install -g xaip-claude-hook && xaip-claude-hook installOr run your own aggregator node — the spec and reference implementation are MIT-licensed with zero runtime dependencies.