Facet Protocol

The index for agent-ready businesses.

Why

Every team building agents that transact ends up writing the same plumbing. An identity verifier. An x402 settlement loop. An audit trail. Five teams, five implementations, none compatible.

The pattern is a protocol, not a feature. So I wrote one, ran a verifier in production at facet.llc, and put both here. If you're building anything in this space, this saves you a few months.

Try the live one

curl -s https://facet.llc
# 402 Payment Required. Identify with a Facet KYA, pay per-query at the Terminal.

Windows note. PowerShell aliases curl to Invoke-WebRequest, which does not accept the -s flag. Use curl.exe -s https://facet.llc instead. The real curl binary ships with Windows 10+.

The site is the demo. Scrape it and you get the protocol response. Send a valid Facet KYA and you get ranked, typed listings to quote, reserve, and settle.

curl -X GET "https://facet.llc/v1/search?q=dallas+plumbing" \
  -H "Authorization: Bearer <Facet KYA>"

What Facet is

Agents identify with a Facet KYA: an ES256 JWT with typ: kya+jwt, sent as Authorization: Bearer <KYA> and verified against its issuer's JWKS. Each KYA is single use, so an agent mints a fresh one per call. The default issuer is Facet's own, https://issuer.facet.llc; a merchant lists the issuers it trusts under KYA-Issuers: in its /.well-known/agents.txt. On top of identity we ship five protocol layers: vertical depth, schema generation, signed response provenance, reputation registry, and an agent WAF.

The three open standards we ride:

Layer	Standard	What we do with it
Discovery	MCP (Anthropic)	POST /ucp/mcp speaks the stateless revision, with 2025-06-18 back-compat
Payments	x402 (Coinbase)	USDC settlement on Base L2
Bot signing	RFC 9421 (Cloudflare)	Verify signed platform requests on UCP checkout

What's in here

• SPEC.md: v0.1 protocol spec, RFC-style. Read this if you're implementing a verifier or a Facet-compliant merchant.
• ARCHITECTURE.md: how the pieces fit, where the trust boundaries are, the protocol-flow diagram.
• schemas/: JSON Schema for all six v0.1 endpoints.
• sdks/typescript/: @facet/sdk-js reference implementation. Verifier (works today) + Terminal client (search/quote/reserve/settle/audit).
• sdks/typescript/examples/hello-agent/: end-to-end demo. One file, walks the whole protocol against facet.llc.
• test-vectors/facet-kya/: conformance vectors. Real ES256-signed JWTs, deterministic against frozen now. 10 vectors covering happy path + every defense.

What's not in here

The hosted Terminal at api.facet.llc is closed. Same for the vertical knowledge graph, schema generator, reputation registry, and agent WAF. Those are how we make money. The spec is open so anyone can verify and integrate.

Status

Version	What's in
v0.0.x (today)	Spec, schemas, Facet KYA verifier, Terminal client (TypeScript), 10 conformance vectors, hello-agent example, CI
v0.1.0 (next)	Ed25519 audit-record verifier, AUDIT.md, multi-rail payments per the stp claim in the Facet KYA
v0.2.0	Python and Go SDK siblings, autogenerated TypeScript types from schemas, merchant-side example apps

License

Apache 2.0. See LICENSE.

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Built by Facet. Spec questions go in issues. RFC discussion lives in discussions.