Send Agent Checkout Message

Sends a message into a checkout run: free text, or an input_response that answers an awaiting_input run by submitting form values, choosing an alternative, or declining. The response acknowledges receipt with a messageId; the agent’s reply arrives as a later message.

API scope required: agent-checkouts.update

POST /unstable/agent-checkouts/{id}/messages

cURL

Answer a Question

curl --request POST \
  --url https://staging.crossmint.com/api/unstable/agent-checkouts/{id}/messages \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '
{
  "id": "msg_answer_1",
  "parts": [
    {
      "action": "submit",
      "requestId": "req_123",
      "response": {
        "answers": {
          "email": "[e-mail]"
        },
        "kind": "form"
      },
      "type": "input_response"
    }
  ]
}
'

202

{
  "messageId": "<string>",
  "status": "accepted"
}

Authorizations

apiKey & userJwtapiKey

X-API-KEY · string · header · required

API key required for authentication

Authorization · string · header · required

The end user's JWT, sent as Authorization: Bearer <JWT> together with a client-side API key. Validated against the project's external JWT configuration.

Headers

x-crossmint-user-id · string

Server-side subject to act on behalf of. Ignored for client-side user auth.

Path Parameters

id · string · required

Minimum string length: 1

Body

application/json

id · string · required

Required string length: 1 - 200

parts · object[] · required

Required array length: 1 element

Option 1

Option 2

Option 3

Option 4

Show child attributes

Response

202

application/json

messageId · string · required

Minimum string length: 1

status · enum<string> · required

Available options: accepted