What is Sill
Sill is the layer between AI agents and your store. It does not replace your store, your payment processor or your hosting; it sits in front of them and answers three questions about every agent interaction:
- Identity — which agent is visiting. Sill matches each visitor against its registry of known AI agents and crawlers, and, on Cloudflare Worker and WordPress plugin installs, checks the request signature when an agent sends one.
- Intent — what the agent is trying to do. In Transactional mode an agent sends a signed request (a mandate) and Sill checks it against your rules before anything is charged.
- Proof — what record remains. Every interaction is written to a signed, append-only audit log that you can export and anyone can verify.
Two modes
Section titled “Two modes”Discovery (live)
Section titled “Discovery (live)”Install the script tag, the WordPress plugin, the Shopify app or the Cloudflare Worker. Sill then:
- Identifies AI-agent traffic against its registry (Anthropic, OpenAI, Google, Perplexity, Microsoft, Meta and more) and logs each visit as a signed record.
- Publishes three agent-readable endpoints for your site at
edge.sill.so, so agents can learn what your store offers:- an A2A-compatible agent card at
https://edge.sill.so/v1/agent-card/{site_key}.json - an MCP server at
POST https://edge.sill.so/v1/mcp/{site_key} - an ARD catalog at
https://edge.sill.so/v1/catalog/{site_key}.json
- an A2A-compatible agent card at
The agent card and the ARD catalog are signed; MCP responses are not. Anyone can check the signatures against Sill’s public key set at https://edge.sill.so/.well-known/jwks.json. See Verify a signature.
Transactional (early access)
Section titled “Transactional (early access)”An agent sends a signed order, Sill evaluates it against your guardrails (approve, reject or hold for a person to review), Stripe authorizes the payment, and Sill writes a signed record of the decision. This runs end to end on the Stripe rail in early access. See the Transactional overview.
What Sill is not
Section titled “What Sill is not”Sill is not a payment processor, money transmitter, fraud system, blockchain, identity-verification service or loyalty platform. Sill evaluates and signs; your processor (Stripe today) holds the card, authorizes the charge, settles and pays out. No funds pass through a Sill account.
How the pieces fit
Section titled “How the pieces fit”| Piece | Where it runs | What it does for you |
|---|---|---|
| Script tag, plugin, Shopify app or Worker | Your site | Lets Sill see agent visits and serves your discovery files. |
| Agent card | edge.sill.so | Tells agents who you are and which skills your store offers. |
| MCP server | edge.sill.so | Lets MCP clients list and call your store’s skills. |
| ARD catalog | edge.sill.so | A signed ai-catalog.json listing your agent endpoints. |
| Rules | Sill | Your rules for what agents may do (Transactional). |
| Audit log | Sill | Signed, chained records of every interaction; exportable. |
| Public key set | edge.sill.so | The keys anyone uses to check Sill’s signatures. |
What’s live today
Section titled “What’s live today”- Discovery is live: the script tag, WordPress plugin, Shopify app, Cloudflare Worker, agent card, MCP server, ARD catalog,
llms.txt, the/agentpage and the public key set. - Transactional is in early access on the Stripe rail. Shopify checkout runs in test mode. Each protocol has its own status; see Protocols.