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

# Create checkout session

> Initiate a payment session to upgrade or change your plan.

```http theme={null}
POST /v1/billing/checkout
```

Creates a checkout session with the appropriate payment provider for your region. The response includes a URL where the user completes payment.

## Request body

<ParamField body="plan_key" type="string" required>
  The plan to subscribe to: `STARTER`, `BUSINESS`, or `ENTERPRISE`.
</ParamField>

<ParamField body="provider" type="string">
  Payment provider to use (`stripe`, `paystack`, or `flutterwave`). If omitted, the provider is selected automatically based on your region. See [billing configuration](/api-reference/billing/config) to check your default provider.
</ParamField>

<ParamField body="success_url" type="string" required>
  URL to redirect the user to after successful payment.
</ParamField>

<ParamField body="cancel_url" type="string" required>
  URL to redirect the user to if they cancel the checkout.
</ParamField>

## Response

<ResponseField name="checkout_url" type="string">
  The hosted checkout page URL. Redirect the user to this URL to complete payment.
</ResponseField>


## OpenAPI

````yaml mint-openapi.yaml POST /v1/billing/checkout
openapi: 3.0.3
info:
  title: Truthlocks API
  description: >
    Truthlocks is a universal verification infrastructure for documents,
    credentials, and digital assets.

    This specification defines the canonical API for interacting with Truthlocks
    services.


    ## Base URLs

    - **Production**: `https://api.truthlocks.com`

    - **Sandbox**: `https://sandbox-api.truthlocks.com`


    ## Authentication

    - **API Keys**: Use `X-API-Key` header for machine-to-machine operations

    - **Bearer Tokens**: Use `Authorization: Bearer <jwt>` for user-initiated
    operations


    ## Tenant Identity

    In production, tenant identity is derived from the authenticated context
    (API key or JWT).

    The `X-Tenant-ID` header is ignored in production to prevent spoofing.
  version: 1.0.0
  contact:
    name: Truthlocks Support
    url: https://truthlocks.com/support
    email: support@truthlocks.com
servers:
  - url: https://api.truthlocks.com
    description: Production API
  - url: https://sandbox-api.truthlocks.com
    description: Sandbox Environment
security:
  - APIKey: []
tags:
  - name: Authentication
    description: API key and token management
  - name: Issuers
    description: Issuer registration and trust management
  - name: Keys
    description: Cryptographic key management for issuers
  - name: Attestations
    description: Attestation lifecycle (mint, revoke, supersede)
  - name: Verification
    description: Attestation verification and proof bundles
  - name: Governance
    description: Issuer governance workflows (admin only)
  - name: Identity
    description: Organization, user, and role management
  - name: Audit
    description: Audit event queries
  - name: Platform
    description: Platform administration (super admin only)
  - name: Platform Review
    description: Staff review workflows for issuer applications
  - name: Tenant Console
    description: Tenant profile and lifecycle endpoints
  - name: Health
    description: Service health and readiness endpoints
  - name: Risk
    description: Risk signal ingestion and fraud detection
  - name: Risk Enforcement
    description: Risk enforcement actions — block, challenge, quarantine, and configuration
  - name: Billing
    description: Billing, subscription, and addon management
  - name: Machine Identity
    description: >-
      Machine Agent Identity Protocol (MAIP) — agent registration, sessions,
      trust, witness, compliance, orchestration, and observability
externalDocs:
  description: Transparency read-only API (separate service spec)
  url: >-
    https://github.com/truthlocks/truthlock/blob/main/docs/transparency/openapi.yaml
paths:
  /v1/billing/checkout:
    post:
      tags:
        - Billing
      summary: Create checkout session
      description: >-
        Creates a hosted checkout session for plan upgrade or subscription
        creation.
      operationId: billing.checkout
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - plan
              properties:
                plan:
                  type: string
                  description: Plan identifier to subscribe to
                success_url:
                  type: string
                  description: URL to redirect after successful checkout
                cancel_url:
                  type: string
                  description: URL to redirect on checkout cancellation
      responses:
        '200':
          description: Checkout session
          content:
            application/json:
              schema:
                type: object
                properties:
                  checkout_url:
                    type: string
                  session_id:
                    type: string
                  expires_at:
                    type: string
        '401':
          description: Authentication required
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorEnvelope'
      security:
        - APIKey: []
components:
  schemas:
    ErrorEnvelope:
      type: object
      required:
        - code
        - message
        - http_status
      properties:
        code:
          type: string
          description: Machine-readable error code
          enum:
            - AUTH_REQUIRED
            - AUTH_INVALID
            - PERMISSION_DENIED
            - TENANT_IDENTITY_UNVERIFIED
            - NOT_FOUND
            - VALIDATION_ERROR
            - CONFLICT
            - PAYLOAD_TOO_LARGE
            - RATE_LIMIT_EXCEEDED
            - QUOTA_EXCEEDED
            - SERVICE_UNAVAILABLE
            - INTERNAL_ERROR
        message:
          type: string
          description: Human-readable error message
        http_status:
          type: integer
          description: HTTP status code
        retry_after_ms:
          type: integer
          description: Milliseconds to wait before retrying (for rate limits)
        details:
          type: object
          description: Additional error context
      example:
        code: AUTH_REQUIRED
        message: Authentication required
        http_status: 401
  securitySchemes:
    APIKey:
      type: apiKey
      in: header
      name: X-API-Key
      description: API key for machine-to-machine authentication

````