---
title: "Create Checkout Session"
method: POST
path: "/api/v1/auth/signup/{session_id}/checkout/create"
tags: ["User APIs", "auth"]
---

# Create Checkout Session

`POST /api/v1/auth/signup/{session_id}/checkout/create`

Create Stripe Checkout session.

Validates:
- Status is EMAIL_VERIFICATION_VERIFIED or PAYMENT_FAILED (allows retry)
- Creates Stripe Checkout session for subscription

## Path parameters

- `session_id` string, required

## Request body

- CheckoutInitiateData
  - `fbp` string, nullable — Meta _fbp browser cookie
  - `fbc` string, nullable — Meta _fbc click ID cookie
  - `marketing_consent` boolean — Visitor granted the CMP's marketing category. Persisted on the signup so the Purchase webhook can honour it later (PRO-3255).
  - `promo_code` string, nullable — Curated ad-attribution promo slug (e.g. utm_campaign when utm_source='promo'); resolved server-side to a Stripe promotion code.

## Response `200`

Successful Response

- SignupCheckoutCreateResponse
  - `session_id` string, required
  - `checkout_session_id` string, required
  - `client_secret` string, nullable
  - `url` string, nullable
  - `status` string, required
  - `capi_event_id` string, nullable
  - `purchase_capi_event_id` string, nullable

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/carbonarc/apis/carbon-arc-client-admin-api.md) · [All operations](https://skmtc.net/carbonarc/apis/carbon-arc-client-admin-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/carbonarc/carbon-arc-client-admin-api/revisions/a8ca30023371/schema)