Create a test clock
The test_clocks.create operation: POST /api/v1/test_clocks in the REST API and the test_clocks_create tool in the MCP server.
/api/v1/test_clocksCreates a test clock (test mode only): a time of its own that customers can be attached to when they are
created (customers.create with testClockId). Their subscriptions then bill at the clock's time: renewals,
trial ends, cancellations and notices happen when you advance the clock (test_clocks.advance), not when real
time passes. Use it to test billing scenarios end to end in seconds.
frozenTime is the clock's starting time (default: now), within a year back and five years ahead. A clock holds
at most 10 customers. Emits test_clock.created.
At a glance
- REST:
POST /api/v1/test_clocks - MCP tool:
test_clocks_create - Operation ID:
test_clocks.create - Scope: Brand
- Permission:
subscriptions:write - Risk tier:
write - Dry run: Supported (send
Ownrecord-Dry-Run: true) - Idempotency:
Idempotency-Keyrequired - Modes: Test mode only
- Authentication: API key with the
subscriptions:writescope - Since: M5
Request
Body
A JSON object (Content-Type: application/json):
| Field | Type | Required | Description |
|---|---|---|---|
name | string | Yes | A name for the clock, e.g. the scenario it tests. |
frozenTime | date-time | No | The clock's starting time (default: now), within a year back and five years ahead. |
Response
201 Created with a JSON object:
| Field | Type | Description |
|---|---|---|
id | clk_… ID | |
object | "test_clock" | |
livemode | false | |
brandId | brd_… ID | |
name | string | |
frozenTime | date-time | The clock's time: its customers' subscriptions bill as if it were now. |
status | one of ready, advancing, internal_failure | ready, advancing (an advance runs: wait for ready) or internal_failure (the last advance stopped on an error, see advance.error; advance again). |
advance | object or null | The latest advance. |
version | integer | |
createdAt | date-time | |
updatedAt | date-time |
Examples
A clock starting now
POST /api/v1/test_clocks
Authorization: Bearer or_test_…
Idempotency-Key: 3f1c9a52-7d0e-4b8f-9a61-0c2d5e8b7f14
Content-Type: application/json
{
"name": "Monthly renewal",
"frozenTime": "2026-10-20T09:00:00.000Z"
}
Response (201):
{
"id": "clk_01jacq4m3xf0v8w9zq2y7k5n6h",
"object": "test_clock",
"livemode": false,
"brandId": "brd_01jacq4m3xf0v8w9zq2y7k5n6b",
"name": "Monthly renewal",
"frozenTime": "2026-10-20T09:00:00.000Z",
"status": "ready",
"advance": null,
"version": 1,
"createdAt": "2026-10-20T09:00:00.000Z",
"updatedAt": "2026-10-20T09:00:00.000Z"
}
Errors
| Code | HTTP status | When | What to do |
|---|---|---|---|
validation_failed | 400 | The name is empty or too long, or frozenTime is out of range. | Fix the fields listed in details.issues and send the request again. |
mode_not_supported | 400 | The request is in live mode: test clocks exist in test mode only. | Use the mode the operation supports (details.supported_mode): test-only operations such as test clocks need test-mode credentials. |
permission_denied | 403 | The credentials can't manage this brand's subscriptions (subscriptions:write). | Ask an organization owner or admin for a role or scope that allows this action. |
It can also return these common errors: api_version_unsupported, invalid_json, unsupported_media_type, authentication_required, api_key_invalid, scope_required, resource_not_found, idempotency_key_required, idempotency_key_reused, idempotency_in_progress, approval_required, approval_rejected, approval_expired, stale_approval, approval_policy_denied, rate_limited, internal_error.