# Start a discussion thread on a record

Opens an internal thread on one record. `subject` is optional — a thread opened from a record needs no title — and `participants` is optional too, since the opener is always seated on their own thread. Several threads per record is deliberate: one deal legitimately carries 'stips before we submit' and 'why did Lender B decline' at once. Answers the new thread, whose id addresses its messages and its roster.

Access class: `def:read`.

## Endpoint

`POST /v1/definitions/{key}/rows/{rowId}/threads`

## Parameters

| Name | In | Type | Required |
| --- | --- | --- | --- |
| key | path | string | Yes |
| rowId | path | string | Yes |

## Request body

Content type: `application/json`.

```json
{
  "body": {
    "participants": [
      "string"
    ],
    "subject": "string"
  },
  "params": {
    ":key": "string",
    ":rowId": ""
  },
  "query": {}
}
```

## Responses

### 201

the action's answer

Content type: `application/json`.

```json
{
  "data": {
    "createdAt": "string",
    "createdBy": 1.5,
    "definitionKey": "string",
    "id": "",
    "messageCount": 1.5,
    "participants": [
      {
        "addedAt": "string",
        "email": "string",
        "isMuted": true,
        "name": "string",
        "role": "string",
        "userId": 1.5
      }
    ],
    "recordName": "string",
    "rowId": "",
    "status": "string",
    "subject": "string",
    "unread": 1.5,
    "updatedAt": "string"
  }
}
```

### default

a refusal: `{"error": "<what a person needs to read>"}`. 401 no credential, 402 the plan does not include this, 403 the seat does not, 404 the thing does not exist or is not yours to see.

Content type: `application/json`.

```json
{
  "error": "string"
}
```