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

# Start a subscription

> Creates a hosted checkout session for a first subscription and returns its URL.

First purchase only. An account that already has a subscription gets
`409`; to move from Individual to Pro use `POST /billing/upgrade`.




## OpenAPI

````yaml /openapi/zebratruth-v1.yaml post /billing/checkout
openapi: 3.1.0
info:
  title: ZebraTruth Compliance API
  version: 1.0.0
  description: >
    AI-powered compliance checking for advertising content. Check text and
    images against

    jurisdiction laws, platform policies, and rights clearance requirements.
    Results include

    embeddable annotations mapped to content locations (text spans, video
    timestamps, image regions).
  contact:
    name: ZebraTruth Support
    email: support@zebratruth.ai
    url: https://developers.zebratruth.ai
  license:
    name: MIT
    url: https://opensource.org/licenses/MIT
servers:
  - url: https://api.zebratruth.ai/v1
    description: Production
security:
  - bearerAuth: []
tags:
  - name: Video Compliance
    description: >
      **Primary endpoint.** Async compliance analysis for video ads. 3-step
      flow:

      get an upload URL, upload the video bytes, submit for analysis. Poll or

      receive an HMAC-signed webhook with the report. Returns timestamped

      findings citing stable evidence IDs (`audio_NNN`, `frame_NNN`, `ocr_NNN`,

      `signal_NNN`). 3-180 second videos. mp4 / webm /

      quicktime. Built for ad agencies and creators.
  - name: Authentication
    description: Validate API keys and check account status
  - name: Compliance
    description: >-
      Run compliance checks on text + image content (sync). For video, use the
      Video Compliance endpoints above.
  - name: Agents
    description: Discover and invoke individual compliance agents
  - name: Jobs
    description: Poll async job status and view execution traces
  - name: Reports
    description: Retrieve and replay compliance reports
  - name: Observability
    description: Request logs and webhook delivery status
  - name: Billing
    description: Subscriptions, plan changes, and credit balance
  - name: Documents
    description: Extract text from PDF and Word documents before or as part of a check
  - name: Check History
    description: List and retrieve past compliance checks for the workspace
  - name: Provenance
    description: Inspect and sign Content Credentials (C2PA) on images and video
  - name: Corpus
    description: >-
      Review queue for proposed changes to the governed legal corpus (dashboard
      session)
  - name: Webhooks
    description: Saved webhook endpoints (dashboard session) and delivery logs
paths:
  /billing/checkout:
    post:
      tags:
        - Billing
      summary: Start a subscription
      description: >
        Creates a hosted checkout session for a first subscription and returns
        its URL.


        First purchase only. An account that already has a subscription gets

        `409`; to move from Individual to Pro use `POST /billing/upgrade`.
      operationId: startCheckout
      requestBody:
        required: false
        content:
          application/json:
            schema:
              type: object
              properties:
                plan:
                  type: string
                  enum:
                    - individual
                    - pro
                  default: pro
                  description: >-
                    Plan to subscribe to. Defaults to `pro` for backward
                    compatibility.
                successUrl:
                  type: string
                  format: uri
                cancelUrl:
                  type: string
                  format: uri
      responses:
        '200':
          description: Checkout session created
          content:
            application/json:
              schema:
                type: object
                properties:
                  url:
                    type: string
                    format: uri
                    description: Hosted checkout page. Redirect the customer here.
        '400':
          description: |
            `invalid_plan` — `plan` was not one of `individual` or `pro`.
        '401':
          $ref: '#/components/responses/Unauthorized'
        '409':
          description: |
            The account already has billing state. Use the billing portal, or
            `POST /billing/upgrade` to move from Individual to Pro.
components:
  responses:
    Unauthorized:
      description: |
        Invalid, missing, or expired API key. Standard error envelope —
        read `message` for the human-readable reason.
      content:
        application/json:
          schema:
            type: object
            description: Standard error envelope.
            required:
              - statusCode
              - message
            properties:
              error:
                type: boolean
                example: true
              url:
                type: string
                format: uri
                example: https://api.zebratruth.ai/v1/whoami
              statusCode:
                type: integer
                example: 401
              statusMessage:
                type: string
                example: Invalid API key
              message:
                type: string
                description: Canonical human-readable reason — pattern-match on this field.
                example: Invalid API key
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: |
        API key starting with `zt_live_` (production) or `zt_test_` (sandbox).
        Get your key at https://developers.zebratruth.ai

````

This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.