> ## Documentation Index
> Fetch the complete documentation index at: https://docs.llmgenerator.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Subscription Checkout

> Create a Stripe checkout session for subscribing to a plan.

## Overview

Creates a Stripe checkout session for subscribing to a plan. Returns a URL where you should redirect the user to complete the payment. Requires session-based authentication (JWT access token).

<Note>
  **For third-party integrations:** Use `POST /subscriptions/checkout/api` with API Key authentication instead.
</Note>

## Authentication

<ParamField header="Authorization" type="string" required>
  Your JWT access token. Format: `Bearer YOUR_ACCESS_TOKEN`
</ParamField>

## Request Body

<ParamField body="planId" type="string" required>
  The plan identifier to subscribe to. Must be one of: `starter`, `professional`, `business`, or `agency`.
</ParamField>

<ParamField body="billingCycle" type="string" default="monthly">
  Billing frequency. Options: `monthly` or `yearly`.
</ParamField>

<ParamField body="successUrl" type="string">
  URL to redirect to after successful payment. Defaults to application dashboard.
</ParamField>

<ParamField body="cancelUrl" type="string">
  URL to redirect to if user cancels payment. Defaults to pricing page.
</ParamField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST https://api.llmgenerator.com/api/v1/subscriptions/checkout \
    -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
    -H "Content-Type: application/json" \
    -d '{
      "planId": "professional",
      "successUrl": "https://yourapp.com/subscription/success",
      "cancelUrl": "https://yourapp.com/pricing"
    }'
  ```

  ```javascript JavaScript theme={null}
  const response = await fetch('https://api.llmgenerator.com/api/v1/subscriptions/checkout', {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer YOUR_ACCESS_TOKEN',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      planId: 'professional',
      successUrl: 'https://yourapp.com/subscription/success',
      cancelUrl: 'https://yourapp.com/pricing'
    })
  });

  const data = await response.json();
  // Redirect user to Stripe checkout
  window.location.href = data.url;
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      'https://api.llmgenerator.com/api/v1/subscriptions/checkout',
      headers={
          'Authorization': 'Bearer YOUR_ACCESS_TOKEN',
          'Content-Type': 'application/json'
      },
      json={
          'planId': 'professional',
          'successUrl': 'https://yourapp.com/subscription/success',
          'cancelUrl': 'https://yourapp.com/pricing'
      }
  )
  data = response.json()
  print(f"Redirect to: {data['url']}")
  ```
</RequestExample>

<ResponseExample>
  ```json Response theme={null}
  {
    "sessionId": "cs_test_a1b2c3d4e5f6g7h8i9j0",
    "url": "https://checkout.stripe.com/c/pay/cs_test_a1b2c3d4...",
    "plan": {
      "id": "professional",
      "name": "Professional",
      "monthlyCredits": 3000,
      "priceCents": 1299
    }
  }
  ```
</ResponseExample>

## Response Fields

<ResponseField name="sessionId" type="string">
  Stripe checkout session ID. Can be used to verify the session later.
</ResponseField>

<ResponseField name="url" type="string">
  URL to redirect the user to for payment. This is a Stripe-hosted checkout page.
</ResponseField>

<ResponseField name="plan" type="object">
  Details of the selected plan.
</ResponseField>

## Checkout Flow

1. **Create session**: Call this endpoint with the desired plan
2. **Redirect user**: Send user to the returned `url`
3. **Payment processing**: User completes payment on Stripe
4. **Webhook**: Stripe notifies your webhook endpoint
5. **Success redirect**: User is redirected to `successUrl`
6. **Verify (optional)**: Check subscription status via `/subscriptions/current`

## Error Responses

<ResponseField name="400">
  Bad Request - Invalid plan ID or user already has an active subscription.
</ResponseField>

<ResponseField name="401">
  Unauthorized - Invalid or missing token.
</ResponseField>

<Note>
  If the user already has an active subscription, they should use the billing portal (`/subscriptions/portal`) to change plans instead.
</Note>

***

## POST /subscriptions/checkout/api

Creates a Stripe checkout session using API Key authentication. Ideal for third-party integrations.

### Authentication

Requires API Key authentication. Include your API key in the `Authorization` header:

```
Authorization: Bearer llmgen_your_api_key_here
```

### Request Body

Same as `/subscriptions/checkout` above.

### Response

Same as `/subscriptions/checkout` above.

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST https://api.llmgenerator.com/api/v1/subscriptions/checkout/api \
    -H "Authorization: Bearer llmgen_your_api_key_here" \
    -H "Content-Type: application/json" \
    -d '{
      "planId": "professional",
      "successUrl": "https://yourapp.com/subscription/success",
      "cancelUrl": "https://yourapp.com/pricing"
    }'
  ```

  ```javascript JavaScript theme={null}
  const response = await fetch('https://api.llmgenerator.com/api/v1/subscriptions/checkout/api', {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer llmgen_your_api_key_here',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      planId: 'professional',
      successUrl: 'https://yourapp.com/subscription/success',
      cancelUrl: 'https://yourapp.com/pricing'
    })
  });

  const data = await response.json();
  // Redirect user to Stripe checkout
  window.location.href = data.url;
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      'https://api.llmgenerator.com/api/v1/subscriptions/checkout/api',
      headers={
          'Authorization': 'Bearer llmgen_your_api_key_here',
          'Content-Type': 'application/json'
      },
      json={
          'planId': 'professional',
          'successUrl': 'https://yourapp.com/subscription/success',
          'cancelUrl': 'https://yourapp.com/pricing'
      }
  )
  data = response.json()
  print(f"Redirect to: {data['url']}")
  ```
</RequestExample>