curl --request POST \
  --url https://commet.co/api/v1/customers/{id}/plan-grants \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "subscriptionId": "<string>",
  "planId": "<string>",
  "reason": "<string>",
  "duration": "cycles",
  "durationCycles": 123
}
'

import { Commet } from "@commet/node";

const commet = new Commet({ apiKey: "ck_xxx" });

const planGrant = await commet.customers.createPlanGrant({
  id: "cus_xxx",
  subscriptionId: "sub_xxx",
  planId: "pln_xxx",
  reason: "Customer requested",
  duration: "cycles",
  durationCycles: 1,
});

from commet import Commet

commet = Commet("ck_xxx")

plan_grant = commet.customers.create_plan_grant(
    "cus_xxx",
    subscription_id="sub_xxx",
    plan_id="pln_xxx",
    reason="Customer requested",
    duration="cycles",
    duration_cycles=1,
)

client, err := commet.New("ck_xxx")
if err != nil {
	log.Fatal(err)
}
ctx := context.Background()

planGrant, err := client.Customers.CreatePlanGrant(ctx, "cus_xxx", &commet.CreatePlanGrantParams{
	SubscriptionID: "sub_xxx",
	PlanID: "pln_xxx",
	Reason: "Customer requested",
	Duration: "cycles",
	DurationCycles: func(value int) *int { return &value }(1),
})
if err != nil {
	log.Fatal(err)
}

import co.commet.Commet;
import co.commet.params.CreatePlanGrantParams;

var commet = Commet.builder().apiKey("ck_xxx").build();

var planGrant = commet.customers().createPlanGrant(
    "cus_xxx",
    CreatePlanGrantParams.builder("sub_xxx", "pln_xxx", "Customer requested", "cycles").durationCycles(1L).build()
);

use Commet\Commet;

$commet = new Commet('ck_xxx');

$planGrant = $commet->customers->createPlanGrant(
    id: 'cus_xxx',
    subscriptionId: 'sub_xxx',
    planId: 'pln_xxx',
    reason: 'Customer requested',
    duration: 'cycles',
    durationCycles: 1,
);

{
  "id": "grant_1a2b3c4d",
  "customerId": "cus_1a2b3c4d",
  "subscriptionId": "sub_1a2b3c4d",
  "basePlanId": "plan_1a2b3c4d",
  "planId": "plan_5e6f7a8b",
  "planReleaseId": "release_5e6f7a8b",
  "status": "active",
  "duration": "until_date",
  "durationCycles": null,
  "startsAt": "2026-09-07T12:00:00.000Z",
  "expiresAt": "2026-10-07T12:00:00.000Z",
  "reason": "Evaluate Business features",
  "source": "api",
  "revokedAt": null,
  "createdAt": "2026-09-07T12:00:00.000Z",
  "updatedAt": "2026-09-07T12:00:00.000Z",
  "events": [
    {
      "id": "event_1a2b3c4d",
      "type": "created",
      "reason": "Evaluate Business features",
      "source": "api",
      "previousExpiresAt": null,
      "expiresAt": "2026-10-07T12:00:00.000Z",
      "duration": "until_date",
      "durationCycles": null,
      "requestedExpiresAt": "2026-10-07T12:00:00.000Z",
      "createdAt": "2026-09-07T12:00:00.000Z"
    }
  ],
  "object": "plan_grant",
  "livemode": false
}

{
  "error": {
    "type": "validation_error",
    "code": "validation_error",
    "message": "The request contains an invalid parameter.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/validation_error.md"
  }
}

{
  "error": {
    "type": "authentication_error",
    "code": "unauthorized",
    "message": "A valid API key is required.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/unauthorized.md"
  }
}

{
  "error": {
    "type": "authentication_error",
    "code": "forbidden",
    "message": "You do not have permission to perform this operation.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/forbidden.md"
  }
}

{
  "error": {
    "type": "not_found_error",
    "code": "not_found",
    "message": "The requested resource was not found.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/not_found.md"
  }
}

{
  "error": {
    "type": "conflict_error",
    "code": "idempotency_in_progress",
    "message": "A request with this idempotency key is still being processed.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/idempotency_in_progress.md"
  }
}

{
  "error": {
    "type": "rate_limit_error",
    "code": "rate_limited",
    "message": "Too many requests. Retry after the interval specified in the Retry-After header.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/rate_limited.md"
  }
}

{
  "error": {
    "type": "internal_error",
    "code": "internal_error",
    "message": "An unexpected error occurred while processing the request.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/internal_error.md"
  }
}

{
  "error": {
    "type": "internal_error",
    "code": "idempotency_unavailable",
    "message": "Idempotency storage is temporarily unavailable. Retry with the same idempotency key.",
    "doc_url": "https://commet.co/docs/api-reference/2026-08-27/errors/idempotency_unavailable.md"
  }
}