Trading Halt Windows

A trading halt window halts trading for a firm at a set time and resumes it at a later time. Windows can run once or repeat on a schedule, and can optionally liquidate the firm when the halt starts.

Admin API Swagger Documentation

• One-time (no repeat): haltTime must be in the future.
• Repeating: only the time of day of haltTime and openTime is used; the date is the first occurrence. The halt and open must fall on the same calendar day (a repeating window cannot cross midnight).

Common repeat values:

POST https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows

{
  "description": "Daily close flatten",
  "enabled": true,
  "haltTime": "2026-10-12T15:55:00",
  "openTime": "2026-10-12T17:00:00",
  "liquidateOnHalt": true,
  "repeat": "* * 1-5",
  "timeZone": "America/Chicago",
  "notificationUrl": "https://hooks.example.com/t4/trading-halt"
}

Returns 201 Created with the new window:

{
  "data": {
    "tradingHaltTimeWindowId": "3f2b8c1e-6a4d-4e2f-9b7a-1c5d8e0f2a31",
    "firmId": "a1b2c3d4-e5f6-4a7b-8c9d-0e1f2a3b4c5d",
    "description": "Daily close flatten",
    "enabled": true,
    "haltTime": "2026-10-12T15:55:00",
    "openTime": "2026-10-12T17:00:00",
    "liquidateOnHalt": true,
    "repeat": "* * 1-5",
    "timeZone": "America/Chicago",
    "notificationUrl": "https://hooks.example.com/t4/trading-halt",
    "nextExecutionTime": "2026-10-12T15:55:00-05:00"
  },
  "metadata": { "timestamp": "2026-10-09T14:00:00Z", "requestId": "..." }
}

nextExecutionTime is the next scheduled halt or open, in the window's time zone. During an active halt it is the pending open. It is omitted when the window is disabled or a one-time window has already run.

GET https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows
GET https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows/{windowID}

The list returns an array of windows in data; get returns a single window. Both use the same format as the create response.

PUT https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows/{windowID}

The body is the same as create and replaces the whole window, so send every field. Returns 200 OK with the updated window.

To pause a window, PUT it with “enabled”: false. To resume, PUT it with “enabled”: true.

DELETE https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows/{windowID}

Returns 204 No Content. Any future halt and open actions are cancelled.

Returns the halt and open actions taken for a window, newest first.

GET https://api.t4login.com/admin/v1/firms/{firmID}/trading-halt-windows/{windowID}/executions?sinceDate=2026-10-01&pageSize=100&pageNumber=1

{
  "data": {
    "items": [
      {
        "tradingHaltTimeWindowId": "3f2b8c1e-6a4d-4e2f-9b7a-1c5d8e0f2a31",
        "description": "Daily close flatten",
        "action": "Open",
        "scheduledTimeUtc": "2026-10-08T22:00:00Z",
        "completedTimeUtc": "2026-10-08T22:00:01Z",
        "status": "Completed"
      },
      {
        "tradingHaltTimeWindowId": "3f2b8c1e-6a4d-4e2f-9b7a-1c5d8e0f2a31",
        "description": "Daily close flatten",
        "action": "Halt",
        "scheduledTimeUtc": "2026-10-08T20:55:00Z",
        "completedTimeUtc": "2026-10-08T20:55:02Z",
        "status": "Completed"
      }
    ],
    "totalCount": 2,
    "pageSize": 100,
    "pageNumber": 1,
    "totalPages": 1
  },
  "metadata": { "timestamp": "2026-10-09T14:00:00Z", "requestId": "..." }
}

When notificationUrl is set, T4 sends a POST with a JSON body to it after every halt and open, whether it succeeded or not. Respond with any 2xx status. Non-2xx responses and timeouts (10 seconds) are retried up to 4 more times with increasing delays.

jobId is the tradingHaltTimeWindowId of the window that ran. taskName is Halt <firm> or Open <firm>.

Success:

{
  "taskId": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "jobId": "3f2b8c1e-6a4d-4e2f-9b7a-1c5d8e0f2a31",
  "taskName": "Halt Acme Trading",
  "executionId": "0b5d3a2e-91f4-4c8a-b6e7-2d4f8a1c9e30",
  "status": "Completed",
  "scheduledTimeUtc": "2026-10-12T20:55:00Z",
  "startedUtc": "2026-10-12T20:55:00.120Z",
  "completedUtc": "2026-10-12T20:55:01.480Z",
  "durationMs": 1360,
  "attempts": 1,
  "httpStatus": 200
}

Failure:

{
  "taskId": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "jobId": "3f2b8c1e-6a4d-4e2f-9b7a-1c5d8e0f2a31",
  "taskName": "Halt Acme Trading",
  "executionId": "5f1c8e7a-2b3d-4e6f-9a0b-c4d5e6f7a8b9",
  "status": "Failed",
  "scheduledTimeUtc": "2026-10-13T20:55:00Z",
  "startedUtc": "2026-10-13T20:55:00.095Z",
  "completedUtc": "2026-10-13T20:55:42.310Z",
  "durationMs": 42215,
  "attempts": 4,
  "httpStatus": 503,
  "error": "Service Unavailable"
}

Validation and other errors return the matching HTTP status with an errors array. Each error has a message and the target field it applies to:

{
  "errors": [
    { "message": "OpenTime must be later than HaltTime.", "target": "openTime" }
  ],
  "metadata": { "timestamp": "2026-10-09T14:00:00Z", "requestId": "..." }
}