curl --request POST \
  --url https://commet.co/api/v1/subscriptions \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "customerId": "<string>",
  "planId": "<string>",
  "offerId": "<unknown>"
}
'

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

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

const createdSubscription = await commet.subscriptions.create({
  customerId: "user_123",
  planId: "pln_xxx",
});

from commet import Commet

commet = Commet("ck_xxx")

created_subscription = commet.subscriptions.create(
    customer_id="user_123",
    plan_id="pln_xxx",
)

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

createdSubscription, err := client.Subscriptions.Create(ctx, &commet.CreateSubscriptionParams{
	CustomerID: "user_123",
	PlanID: func(value string) *string { return &value }("pln_xxx"),
})
if err != nil {
	log.Fatal(err)
}

import co.commet.Commet;
import co.commet.params.CreateSubscriptionParams;

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

var createdSubscription = commet.subscriptions().create(
    CreateSubscriptionParams.builder("user_123").planId("pln_xxx").build()
);

use Commet\Commet;

$commet = new Commet('ck_xxx');

$createdSubscription = $commet->subscriptions->create(
    customerId: 'user_123',
    planId: 'pln_xxx',
);

{
  "id": "sub_1a2b3c4d",
  "customerId": "cus_1a2b3c4d",
  "plan": {
    "id": "plan_1a2b3c4d",
    "name": "Pro"
  },
  "name": "Pro",
  "description": null,
  "status": "pending_payment",
  "billingInterval": "monthly",
  "trialEndsAt": null,
  "currentPeriod": null,
  "cancellation": null,
  "cancelAtPeriodEnd": false,
  "scheduledPlanChange": null,
  "startDate": "2026-09-07T12:00:00.000Z",
  "endDate": null,
  "billingDayOfMonth": null,
  "nextBillingDate": null,
  "checkoutUrl": "https://commet.co/checkout/example_checkout_token",
  "createdAt": "2026-09-07T12:00:00.000Z",
  "updatedAt": "2026-09-07T12:00:00.000Z",
  "offerApplications": [],
  "pause": null,
  "priceId": "price_1a2b3c4d",
  "object": "subscription",
  "livemode": false,
  "checkoutProvider": "commet"
}

{
  "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"
  }
}