One streamed model turn for the merchant console's agents

POST/v1/merchants/{merchantId}/assistant

Streams the Messages API events as newline-delimited JSON (the Anthropic SDK's MessageStream.toReadableStream). Each merchant has a daily budget; once it is spent the turn runs on claude-haiku-5-5, named in Keelson-Model.

Path parameters

merchantIdstringRequired

Headers

Content-Typeapplication/jsonRequired
Idempotency-KeystringRequired: 1 to 255 characters. A retry with the same key returns the first answer.

Request body

application/json

modelstring: One of claude-opus-5-5claude-haiku-5-5
systemstringRequired
messagesarray of objectRequired
toolsarray of object
tool_choicestring: One of autonone

Responses

200The turn's events
401No session
403The session is not this merchant's
429Too many turns, or today's budget is spent
502The model provider refused the turn
503No model provider configured

200 response

curl -X POST https://api.keelson.finance/v1/merchants/{merchantId}/assistant \
  -H 'content-type: application/json' \
  -H "idempotency-key: $(uuidgen)" \
  --data '{"model":"claude-opus-5-5","system":"string","messages":[{"role":"user","content":"string"}],"tools":[{"name":"string","description":"string","input_schema":{}}],"tool_choice":"auto"}'

const res = await fetch("https://api.keelson.finance/v1/merchants/{merchantId}/assistant", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "idempotency-key": crypto.randomUUID(),
  },
  body: JSON.stringify({
    "model": "claude-opus-5-5",
    "system": "string",
    "messages": [
      {
        "role": "user",
        "content": "string"
      }
    ],
    "tools": [
      {
        "name": "string",
        "description": "string",
        "input_schema": {}
      }
    ],
    "tool_choice": "auto"
  }),
});
const data = await res.json();

Response · shape from the schema

"string"