What is Sill
Sill is the layer between an arriving AI agent and a merchant’s commerce stack. It does not replace the merchant’s existing systems; it sits in front of them and answers three questions about every agent interaction:
- Identity — who is the visitor, established by a signed agent card.
- Intent — what they are trying to do, expressed as a signed mandate (Transactional mode).
- Proof — what record remains, written to an append-only, signed, Merkle-chained audit envelope.
Two product modes
Section titled “Two product modes”Discovery (live)
Section titled “Discovery (live)”A one-line embed script identifies AI-agent traffic against a seeded identity registry (Anthropic, OpenAI, Google, and others), logs each agent interaction to the signed audit envelope, and exposes per-site, signed, agent-readable manifests at Sill’s edge:
- A2A-compatible agent card at
https://edge.sill.so/v1/agent-card/{site_key}.json - Streamable-HTTP MCP server at
POST https://edge.sill.so/v1/mcp/{site_key} - ARD
ai-catalog.jsonathttps://edge.sill.so/v1/catalog/{site_key}.json
Every signed surface can be verified independently against Sill’s public JWKS at https://edge.sill.so/.well-known/jwks.json. See Verify a signature.
Transactional (Phase 2)
Section titled “Transactional (Phase 2)”The Transactional pipeline — signed mandate → policy evaluation → payment authorization → signed, Merkle-chained audit record — has been validated end-to-end on the live Stripe rail in production, at dogfood scope (small real charges on a single Sill-controlled account, not scaled multi-merchant volume). See the Transactional overview for the honest bounds.
What Sill is not
Section titled “What Sill is not”Sill is not a payments processor, money transmitter, PCI-certified entity, fraud system, blockchain, identity-verification service, or loyalty platform. Sill evaluates and signs; the actual money movement is handed to the merchant’s processor (Stripe today). The merchant’s processor holds the card, authorizes the charge, settles, and pays out. No funds enter a Sill-controlled account at any step.
How the pieces fit
Section titled “How the pieces fit”| Layer | Where it runs | What it does |
|---|---|---|
| Embed script | Merchant page → Sill edge | Identifies the visiting agent, beacons the interaction. |
| Agent card | Sill edge | Publishes signed identity + capabilities per site. |
| MCP server | Sill edge | Exposes the site’s backed skills to MCP clients. |
| ARD catalog | Sill edge | Publishes a signed ai-catalog.json manifest per site. |
| Mandate engine | Sill edge | (Transactional) evaluates and signs a mandate. |
| Policy engine | Sill edge | (Transactional) applies the active rule set. |
| Audit envelope | Sill origin | Stores signed, Merkle-chained records; supports export. |
| Public JWKS | Sill edge | Publishes the ed25519 signing key for third-party verification. |
Phase posture
Section titled “Phase posture”- Phase 1 — Discovery — SHIPPED and LIVE. All Phase-1 deliverables are deployed.
- Phase 2 — Transactional core — LIVE in dogfood validation on the live Stripe rail. Shopify live-rail is a separate gate and has not been flipped (test-mode only). ACP, UCP, and x402 are on the roadmap.