Facet UCP Shopping

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

The independent agent-commerce protocol for AI-agent checkout on any online store.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "Facet UCP Shopping": {
      "url": "https://api.facet.llc/ucp/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (23)

• search_catalog

  Search the merchant catalog for products matching a free-text query.

  Parameters:

  • catalog (required) — object

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• lookup_catalog

  Look up one or more products or variants by identifier (batch).

  Parameters:

  • catalog (required) — object

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_product

  Get full product detail by product or variant identifier.

  Parameters:

  • catalog (required) — object

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• discover_businesses

  Find businesses in the Facet Universal Business Index that an agent can transact with. Returns `featured` (claimed merchants with a live `terminal_url` — point your catalog and checkout calls there) and `results` (the wider directory). Use this first when you do not already know which merchant to talk to. REQUIRES IDENTITY: send a Facet KYA as `Authorization: Bearer <kya>` on the MCP request. A KYA is an ES256 JWT from Facet's default issuer https://issuer.facet.llc (or another issuer this Terminal trusts — see KYA-Issuers in its /.well-known/agents.txt). Calling without one returns 401 with a signup link.

  Parameters:

  • near — object — Optional geographic center to rank by proximity.
  • limit — integer — Max matches to return. Default 10, cap 50.
  • query — string — Free-text query, e.g. "flowers" or "makeup brushes".
  • radius_km — number — Search radius around `near`, km. Default 25.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• discover_products

  Search products ACROSS every merchant in the Facet network that has opted into cross-merchant discovery. Returns matches each carrying the selling merchant's `terminal_url` (point your catalog and checkout calls there). Filter by free-text `query` (product name + description), exact `category`, and/or `tags` (all must be present); at least one filter is required. Use this when you know WHAT you want but not WHICH merchant sells it. REQUIRES IDENTITY: send a Facet KYA as `Authorization: Bearer <kya>` on the MCP request. A KYA is an ES256 JWT from Facet's default issuer https://issuer.facet.llc (or another issuer this Terminal trusts; see KYA-Issuers in its /.well-known/agents.txt). Calling without one returns 401 with a signup link.

  Parameters:

  • tags — array — Tags that must ALL be present on a matching product.
  • limit — integer — Max matches to return. Default 10, cap 50.
  • query — string — Free-text over product name + description, e.g. "lavender soap".
  • category — string — Exact product category to match.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_quote

  Get the real landed cost of a product from this merchant: goods + shipping + tax for a specific destination, plus a signed `quote_token` the payment path binds to. Call this before paying — the token is what makes the price the MERCHANT's, not one you name. Physical products REQUIRE a `fulfillment` ship-to; without one you get FULFILLMENT_REQUIRED. An unserviceable destination returns UNDELIVERABLE (the merchant's own shipping zones, which Facet cannot waive). REQUIRES IDENTITY: send a Facet KYA as `Authorization: Bearer <kya>` (ES256 JWT from https://issuer.facet.llc, or another issuer in this Terminal's agents.txt KYA-Issuers).

  Parameters:

  • product_id (required) — string — Product or variant id, e.g. from search_catalog.
  • qty — integer — Quantity. Default 1.
  • site_id — string — Usually omitted — this Terminal's bound site is used.
  • fulfillment — object — Ship-to destination. REQUIRED for physical products.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_payment_capabilities

  Which settlement rails this merchant actually accepts (e.g. coin/boson-escrow for escrowed funds that release on fulfilment, coin/usdc-base for direct). Call before get_payment_requirements so you pass a rail_id this merchant registers, rather than guessing. No identity required — this is discovery data.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_payment_requirements

  Turn a `quote_token` from get_quote into a seller-signed payment offer to authorize. Returns `requirements` (escrow address, asset, exact atomic amount, network) — sign it LOCALLY with your own wallet (e.g. @bosonprotocol/x402-client handle402 for `coin/boson-escrow`, producing an X-PAYMENT string). Facet never holds your key and cannot sign for you, which is why paying is two steps and not one. The offer binds to the quote_token's sealed landed total and ship-to, so the amount is the merchant's, not one you name. REQUIRES IDENTITY: same Facet KYA as get_quote, and the SAME `aid` — the offer path rejects a quote_token issued to a different agent than the caller.

  Parameters:

  • product_id (required) — string — Must match the product the quote_token sealed.
  • rail_id (required) — string — Settlement rail, e.g. "coin/boson-escrow" (escrow: funds release on fulfilment) or "coin/usdc-base". See /v1/payments/capabilities for what this merchant registers.
  • amount (required) — object — The landed total in ATOMIC units. Must equal the quote_token's sealed total.
  • quote_token (required) — string — The signed token from get_quote.
  • qty — integer — Must match the quote_token. Default 1.
  • site_id — string — Usually omitted — this Terminal's bound site is used.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_order

  Read back one of YOUR orders on this merchant: status, amount, settlement state. Use the order_id returned when you paid. You can only read orders your own agent identity placed — another agent's order returns FORBIDDEN. REQUIRES IDENTITY: Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • order_id (required) — string — The order id returned at payment.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• list_orders

  List YOUR order history on this merchant, newest first. Scoped to your own agent identity — you never see another agent's orders. REQUIRES IDENTITY: Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • limit — integer — Max orders to return.
  • cursor — string — Opaque cursor from a previous page.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• post_delivery_refund

  Request a refund or return on a DELIVERED order you placed on this merchant. Opens a merchant-approved refund ticket (status `requested`); it moves NO money on its own. The merchant reviews and approves it, and only then does the send-back sign from the merchant's OWN wallet (non-custodial). Amount and recipient are NOT inputs: the refund amount is derived and capped server-side, and the recipient is the order's stamped payer, never one you name. Pass `refund_line_items` to refund only part of the order; omit for the whole order. Owner-scoped: another agent's order returns FORBIDDEN. REQUIRES IDENTITY: a Facet KYA as `Authorization: Bearer <kya>` (an ES256 JWT from https://issuer.facet.llc, or another issuer in this Terminal's agents.txt KYA-Issuers). A wallet-bound KYA also authorizes a platform-originated order by its stamped payer.

  Parameters:

  • order_id (required) — string — The order id returned at payment (settle / checkout complete). A reservation id is not an order id.
  • reason (required) — string — Why the refund or return is requested. Required.
  • receipt — object — Optional Ed25519-signed settlement receipt (the signed settle response you received). When valid and bound to this order it records receipt_verified on the ticket; it never gates the refund.
  • refund_line_items — array — Optional PARTIAL selection: refund only these lines instead of the whole order. Advisory at request time; the merchant is authoritative and may adjust it at decide. Omit for a full-order refund.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• wishlist_add

  Save a product to YOUR wishlist on this merchant for later. Idempotent: saving the same product again updates its note and keeps the original save time. Scoped to your own agent identity. REQUIRES IDENTITY: Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • product_id (required) — string — The product id to save.
  • note — string — Optional short note. No personal data.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• wishlist_list

  List YOUR saved items (wishlist) on this merchant, newest first. Scoped to your own agent identity, so you never see another agent's list. REQUIRES IDENTITY: Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • limit — integer — Max items to return.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• wishlist_remove

  Remove a product from YOUR wishlist on this merchant. Idempotent: removing something not on your list succeeds with removed:false. Scoped to your own agent identity. REQUIRES IDENTITY: Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • product_id (required) — string — The product id to remove.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• create_checkout

  Open a checkout session for one or more catalog line items (or promote a cart with `cart_id`). Returns the session plus server-resolved `payment_handlers` (rail, pay_to, exact amount) to satisfy: the price and pay_to are the MERCHANT's, sealed here, never read from your request. Physical goods REQUIRE a `fulfillment` ship-to (else FULFILLMENT_REQUIRED), sealed at create. REQUIRES IDENTITY on a signature-required Terminal: a Facet KYA as `Authorization: Bearer <kya>`.

  Parameters:

  • cart_id — string — Promote an existing cart: its stored lines drive the checkout and any line_items are ignored (the business must use the cart contents).
  • line_items — array — Items to buy, each `{ item: { id }, quantity }`. Omit when using cart_id.
  • fulfillment — object — Ship-to destination. REQUIRED for physical products; sealed at create.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• complete_checkout

  Complete a checkout you created and place the order by submitting the buyer-signed payment credential. This is the MONEY-MOVING leg: funds capture on-chain to the merchant's pay_to (x402) or into escrow (Boson). The amount is re-derived server-side from the reservation, never your request, and the buyer's signature is verified before any capture. A per-buyer refusal (FORBIDDEN, cap-exceeded, FULFILLMENT_REQUIRED) returns as an error result; a missing or invalid identity is a real 401. REQUIRES IDENTITY plus a signed Idempotency-Key on a signature-required Terminal.

  Parameters:

  • checkout_id (required) — string — The checkout id from create_checkout.
  • payment (required) — object — The payment container `{ instruments: [{ credential: { type, ... } }] }`, where credential.type is `x402_authorization` or `boson_commit_authorization`. Sign the seller-signed offer LOCALLY with your own wallet; Facet never holds your key.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_checkout

  Read back one of YOUR checkout sessions by id: status, totals, line items, payment_handlers. Owner-scoped, so another agent's id returns not_found. REQUIRES IDENTITY on a signature-required Terminal.

  Parameters:

  • id (required) — string — The checkout session id.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• update_checkout

  Return a checkout's CURRENT sealed snapshot. Facet seals price and items at create, so this is a no-op that reports the session plus a note: to change line items, update the cart and start a new checkout with create_checkout(cart_id). Owner-scoped.

  Parameters:

  • id (required) — string — The checkout session id.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• cancel_checkout

  Cancel a checkout session before completion, releasing its inventory hold. Idempotent, owner-scoped, and moves no money (distinct from an escrow refund). REQUIRES IDENTITY plus an Idempotency-Key on a signature-required Terminal.

  Parameters:

  • id (required) — string — The checkout session id.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• create_cart

  Create a pre-checkout cart from catalog line items. A cart is a mutable scratchpad: it moves no money and holds no inventory, so it carries estimated (server-derived) totals and NO payment_handlers. Assemble it, then create_checkout(cart_id) to convert. REQUIRES IDENTITY on a signature-required Terminal.

  Parameters:

  • line_items — array — Items, each `{ item: { id }, quantity }`. Prices are catalog-derived, never yours.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• get_cart

  Read back one of YOUR carts by id: line items and estimated totals. Owner-scoped, so another agent's id returns not_found. REQUIRES IDENTITY on a signature-required Terminal.

  Parameters:

  • id (required) — string — The cart id.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• update_cart

  Replace a cart's line items (full replacement), re-priced server-side. Owner-scoped. REQUIRES IDENTITY on a signature-required Terminal.

  Parameters:

  • id (required) — string — The cart id.
  • line_items — array — The new full set of items, each `{ item: { id }, quantity }`.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• cancel_cart

  Cancel a cart. Idempotent, owner-scoped, and moves no money. REQUIRES IDENTITY plus an Idempotency-Key on a signature-required Terminal.

  Parameters:

  • id (required) — string — The cart id.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

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