> ## Documentation Index > Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt > Use this file to discover all available pages before exploring further. # Respond to User Action > Submits or declines a pending user action on an agent checkout. The `actionId` is the `pendingUserAction.id` from the checkout view, supplied **in the path only** — including it in the body is rejected. A `submit` must carry `values` that satisfy the action's `responseSchema`. The response is an acknowledgement; more actions may follow, so return to polling `GET /{id}` afterwards. **API scope required**: `agent-checkouts.update` ## OpenAPI ````yaml post /unstable/agent-checkouts/{id}/actions/{actionId} openapi: 3.0.3 info: title: Crossmint Agent Checkouts API version: unstable description: >- Drive a real, automated browser session through any merchant's checkout on behalf of a signed-in user. You hand the API a product URL, an optional natural-language instruction, and a hard maximum cost. Crossmint runs a browser through the merchant's checkout pages, pausing for *user actions* (shipping, payment, anything only a human can answer) which you respond to with values that satisfy a supplied JSON Schema. There are no webhooks in v1 — poll the checkout until it reaches a terminal state. ## Base URL `https://www.crossmint.com/api` (production) · `https://staging.crossmint.com/api` (staging) ## Authentication Every request requires **two** credentials: - `X-API-KEY` — a client-side API key (`ck_...`) with the `agent-checkouts.*` scopes. - `Authorization: Bearer ` — a JWT identifying the end user, issued by an external auth provider your project trusts. Without it the API returns `401`. This API lives under the `unstable` namespace. The schema may change — pin and re-test on upgrades. servers: - url: https://www.crossmint.com/api description: Production - url: https://staging.crossmint.com/api description: Staging security: - ApiKeyAuth: [] BearerAuth: [] tags: - name: Agent Checkouts description: Create, poll, respond to, and cancel browser-driven checkouts. - name: Buyer Profiles description: >- Subject-scoped buyer identity and shipping address the agent can prefill during a checkout run. Payment data is never stored. paths: /unstable/agent-checkouts/{id}/actions/{actionId}: post: tags: - Agent Checkouts summary: Respond to User Action description: >- Submits or declines a pending user action on an agent checkout. The `actionId` is the `pendingUserAction.id` from the checkout view, supplied **in the path only** — including it in the body is rejected. A `submit` must carry `values` that satisfy the action's `responseSchema`. The response is an acknowledgement; more actions may follow, so return to polling `GET /{id}` afterwards. **API scope required**: `agent-checkouts.update` operationId: respondToAgenticCheckoutAction parameters: - $ref: '#/components/parameters/CheckoutId' - $ref: '#/components/parameters/ActionId' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/RespondToActionRequest' examples: Submit values: summary: Submit values for the pending action value: action: submit values: fullName: Ada Lovelace addressLine1: 12 Analytical Engine Way city: London postalCode: EC1A 1BB country: GB Decline: summary: Decline the pending action value: action: decline reason: Shipping cost above the user's budget responses: '201': description: The submission or decline was accepted. content: application/json: schema: $ref: '#/components/schemas/ActionAccepted' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' components: parameters: CheckoutId: name: id in: path required: true description: The agent checkout id (returned by create). schema: type: string format: uuid ActionId: name: actionId in: path required: true description: The id of the pending user action (`pendingUserAction.id`). schema: type: string format: uuid schemas: RespondToActionRequest: oneOf: - type: object required: - action - values properties: action: type: string enum: - submit values: type: object additionalProperties: true description: Values satisfying the action's `responseSchema`. - type: object required: - action properties: action: type: string enum: - decline reason: type: string minLength: 1 maxLength: 1000 description: Optional reason for declining. ActionAccepted: type: object required: - checkoutId - actionId - status - acceptedAt properties: checkoutId: type: string format: uuid actionId: type: string format: uuid status: type: string enum: - accepted acceptedAt: type: string format: date-time Error: type: object properties: statusCode: type: integer error: type: string message: type: string responses: BadRequest: description: The request body or parameters were invalid. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: >- Missing or invalid authentication. A valid `X-API-KEY` and `Authorization: Bearer ` are both required. content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: >- The API key lacks the required scope, or Agent Checkouts is not enabled for this project. content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: No checkout, action, or buyer profile with the given id. content: application/json: schema: $ref: '#/components/schemas/Error' Conflict: description: >- The action can no longer be responded to (e.g. it expired or was already handled). content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-KEY description: Client-side API key (`ck_...`) with the `agent-checkouts.*` scopes. BearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- JWT identifying the end user, issued by an external auth provider your project trusts. ````