> ## Documentation Index > Fetch the complete documentation index at: https://docs.farthing.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Farthing's primary integrator is an autonomous agent or the developer wiring one up. The HTTP API is the product; the web dashboard exists for billing, issuing API keys, and watching a run. > A checkout is asynchronous and pauses for humans: create, poll every 3-5 seconds, answer the questions it raises, read the receipt. A run takes 2-3 minutes and can park for up to 10 minutes on one question. Never present it as a synchronous request/response call. > Branch on pendingUserAction.key. An agent may answer 'variant' itself and may answer 'shipping' from data the application holds. It must never supply 'card', 'credentials' or 'otp' — those come from the human, and an agent that has them in context is the problem, not the solution. > Base URL is https://api.farthing.ai and auth is Authorization: Bearer ck_test_... or ck_live_.... API keys carry scopes; give an agent the narrowest set that does its job. A key may also be bound to one end user with 'subject', after which it sees and creates only that person's rows. > POST /v1/checkouts takes an Idempotency-Key header. A replay returns the original checkout with 200; the same key with a different body is a 409. Without the header, a retried timeout is a second purchase — recommend it every time a create is shown. > Pricing: sandbox is free with no card; paid plans are Personal $9, Business $49, Scale $249 per month, plus a flat $1.00 per COMPLETED checkout on every tier. Failed and cancelled checkouts are never billed. Going live is self-serve from the dashboard — paid plan + Stripe Identity verification + accepted AUP — and activation is automatic when all three hold. > Every example in these docs is a shape the API actually produces. Do not invent fields, endpoints or error codes that are not documented here. # List API keys > Answers `{ data, keys, nextCursor }`: `data` is the field the checkout and buyer-profile lists also use and the one to read, `keys` is the same array under its original name, and `nextCursor` is always `null` because this collection is not paged. Newest first. **Revoked keys are included**, with `revokedAt` set — filter client-side if you only want active ones. Listing never returns a secret. `keyPrefix` is the most a list can show. Requires the `api-keys.read` scope. A subject-bound key cannot call this: the key list is a tenant-wide fact, and a credential acting for one end user must not be able to enumerate its siblings. `403`. ## OpenAPI ````yaml /openapi.json get /v1/api-keys openapi: 3.1.0 info: title: Farthing API version: 1.0.0 summary: >- Agentic checkout. Give it a product URL and a plain-English request; it drives a real browser to a completed purchase and asks a human only when it must. description: >- The HTTP API is the product. Everything an integration needs — creating checkouts, answering the questions a run stops on, storing buyers, issuing scoped keys — is here. A checkout is asynchronous and pauses for humans. `POST /v1/checkouts` returns in milliseconds with a `queued` object; the run itself takes minutes and may park on a `pendingUserAction` for up to ten. Poll `GET /v1/checkouts/{id}` (unmetered) or register a webhook endpoint. Not covered by this spec: the live-view embed (`GET /embed/{checkoutId}` and `GET /embed/{checkoutId}/stream`). Those are consumed by a browser, authenticate with a short-lived JWT minted at `POST /v1/checkouts/{id}/embed-token` rather than with an API key, and return HTML and `text/event-stream`. Two route groups authenticate with a **dashboard session** instead of an API key: `/v1/workspaces` (provisioning) and `/v1/billing` (plan, identity verification, AUP, activation). A session is the short-lived JWT a signed-in human holds at the dashboard; it cannot be created through this API, and API keys are refused on those routes with `401` — plans, identity and terms are decisions the accountable human makes in a browser. Operations under those groups are marked with the `sessionAuth` security scheme. contact: name: Farthing url: https://docs.farthing.ai servers: - url: https://api.farthing.ai description: Production security: - bearerAuth: [] tags: - name: Signup description: Self-serve account creation. The only unauthenticated write on the API. - name: Checkouts description: Create a run, poll it, cancel it, and answer what it asks. - name: Buyer profiles description: >- Reusable identity and shipping details, referenced by id when creating a checkout. - name: Buyer sessions description: >- Stored merchant logins captured by a `credentials` action. Read-only metadata and revocation. - name: Webhooks description: >- Endpoints that receive `checkout.status_changed` with an HMAC-SHA256 signature. - name: API keys description: >- Self-serve key issuance and revocation. Keys carry scopes; a key can never mint one broader than itself. - name: Usage description: Completed checkouts by day, and gross merchandise volume by currency. - name: Workspaces description: >- Dashboard-session workspace provisioning. One workspace per account; the first request of a fresh sign-in is “do I have a workspace?” and the second is “make me one”. - name: Billing description: >- Dashboard-session billing: plan, identity verification, AUP, and the activation checklist. Session-only — an agent's key completes checkouts, it does not choose subscription plans. - name: Health description: Liveness. paths: /v1/api-keys: get: tags: - API keys summary: List API keys description: >- Answers `{ data, keys, nextCursor }`: `data` is the field the checkout and buyer-profile lists also use and the one to read, `keys` is the same array under its original name, and `nextCursor` is always `null` because this collection is not paged. Newest first. **Revoked keys are included**, with `revokedAt` set — filter client-side if you only want active ones. Listing never returns a secret. `keyPrefix` is the most a list can show. Requires the `api-keys.read` scope. A subject-bound key cannot call this: the key list is a tenant-wide fact, and a credential acting for one end user must not be able to enumerate its siblings. `403`. operationId: listApiKeys responses: '200': description: >- Every key on the tenant, newest first, revoked ones included. Not paged. content: application/json: schema: type: object required: - data - keys - nextCursor properties: data: type: array items: $ref: '#/components/schemas/ApiKeySummary' description: >- The collection. Read this one — it is the field the checkout and buyer-profile lists answer with too. (`GET /v1/buyer-sessions` is the one list route that has not converged: it answers `{ sessions, vaultEnabled }`.) keys: type: array items: $ref: '#/components/schemas/ApiKeySummary' description: >- The same array under the field's original name, kept because existing callers read it. Identical contents; prefer `data` in new code. nextCursor: type: - string - 'null' description: >- Always `null` here — the collection is small and tenant-bounded, so there is nothing to page. Present so a generic list client needs no special case. example: data: - id: 2a44c7f0-1b23-4a95-9d0e-77e1b6c4a812 label: agent for user_a91f mode: live scopes: - checkouts.write subject: user_a91f keyPrefix: ck_live_9Hf2QzT lastUsedAt: '2026-07-29T09:14:31.190Z' revokedAt: null createdAt: '2026-07-29T09:02:10.771Z' - id: 8b7c6d5e-4f30-4a21-9b8c-0d1e2f3a4b5c label: ci mode: test scopes: - '*' subject: null keyPrefix: ck_test_3sQd7yQ lastUsedAt: null revokedAt: '2026-07-27T11:44:09.331Z' createdAt: '2026-07-20T08:15:02.640Z' keys: - id: 2a44c7f0-1b23-4a95-9d0e-77e1b6c4a812 label: agent for user_a91f mode: live scopes: - checkouts.write subject: user_a91f keyPrefix: ck_live_9Hf2QzT lastUsedAt: '2026-07-29T09:14:31.190Z' revokedAt: null createdAt: '2026-07-29T09:02:10.771Z' - id: 8b7c6d5e-4f30-4a21-9b8c-0d1e2f3a4b5c label: ci mode: test scopes: - '*' subject: null keyPrefix: ck_test_3sQd7yQ lastUsedAt: null revokedAt: '2026-07-27T11:44:09.331Z' createdAt: '2026-07-20T08:15:02.640Z' nextCursor: null '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' components: schemas: ApiKeySummary: type: object title: ApiKeySummary required: - id - label - mode - scopes - subject - keyPrefix - lastUsedAt - revokedAt - createdAt properties: id: type: string format: uuid label: type: - string - 'null' mode: type: string enum: - test - live scopes: type: array items: $ref: '#/components/schemas/Scope' description: >- `["*"]` for a full-access key, including every key issued before scopes existed. subject: type: - string - 'null' description: >- The end user this key acts for, or `null` for a tenant-wide key. Always present here, unlike on the creation response. This listing is the only place to audit which of your keys act for whom — and a subject-bound key cannot read it. examples: - user_a91f keyPrefix: type: - string - 'null' description: >- The first 16 characters. Safe to store and display — it identifies which key without being one. lastUsedAt: type: - string - 'null' format: date-time description: >- Written best-effort on every authenticated request; never blocks it. A good rotation signal, not an audit log. revokedAt: type: - string - 'null' format: date-time createdAt: type: string format: date-time Scope: type: string title: Scope description: >- `.read` or `.write`, or the wildcard `*`. `write` implies `read` on the same resource. Resources are exactly the route groups under `/v1`. enum: - '*' - checkouts.read - checkouts.write - buyer-profiles.read - buyer-profiles.write - buyer-sessions.read - buyer-sessions.write - webhooks.read - webhooks.write - api-keys.read - api-keys.write - usage.read - usage.write Error: type: object title: Error description: >- Every error is this object. There are no error codes: match on the HTTP status, treat `message` as text for a human. required: - error - message properties: error: type: boolean const: true message: type: string ScopeError: type: object title: ScopeError description: An out-of-scope request. `requiredScope` saves you parsing the message. required: - error - message - requiredScope properties: error: type: boolean const: true message: type: string requiredScope: $ref: '#/components/schemas/Scope' responses: Unauthorized: description: >- Missing, malformed, invalid or revoked bearer token. There is no distinction between "never existed" and "revoked" — that difference is only useful to someone probing. content: application/json: schema: $ref: '#/components/schemas/Error' examples: missing: value: error: true message: Missing bearer token invalid: value: error: true message: Invalid or revoked API key Forbidden: description: >- The key is missing the scope this route requires, the tenant is suspended, or the key is bound to one end user and this route answers an account-wide question. content: application/json: schema: anyOf: - $ref: '#/components/schemas/ScopeError' - $ref: '#/components/schemas/Error' examples: scope: value: error: true message: This API key is missing the 'buyer-profiles.read' scope. requiredScope: buyer-profiles.read suspended: value: error: true message: Tenant suspended subjectBound: summary: A subject-bound key reaching for a tenant-wide fact value: error: true message: A subject-bound key cannot read account usage. securitySchemes: bearerAuth: type: http scheme: bearer description: >- `Authorization: Bearer ck_test_…` or `ck_live_…`. There is no other auth scheme — no query-string keys, no request signing, no OAuth. ````