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

# Answer the webhook challenge

> The GET verification some systems perform before sending the first event.



## OpenAPI

````yaml openapi/en/cell.json GET /v1/ingest/webhook/{source_id}
openapi: 3.1.0
info:
  title: Niadra data API
  version: '1'
  description: >-
    Writing, context, history, objects, identity, privacy and governance of one
    space. Every space has a stable address, with the space and the region in
    its name.
servers:
  - url: https://{space}.{region}.api.niadra.com
    variables:
      space:
        default: acme-prod
        description: The space, which comes in the source key.
      region:
        default: us-east-1
        description: The region of the space, which also comes in the key.
security: []
paths:
  /v1/ingest/webhook/{source_id}:
    get:
      tags:
        - ingest
      summary: Answer the webhook challenge
      description: >-
        Some systems check a webhook address with a `GET` before they send the
        first event. When the mapping of the source names a verification
        parameter, Niadra answers with the value of that query parameter as
        plain text; with `url_token` authentication the token is checked first.
        Without a configured challenge the answer is 404.


        **Authentication.** Authentication declared in the mapping of the
        source: bearer, HMAC signature, URL token or mTLS. No source key.
      operationId: webhook_challenge_v1_ingest_webhook__source_id__get
      parameters:
        - in: path
          name: source_id
          required: true
          schema:
            format: uuid
            title: Source Id
            type: string
          description: The source configured for this system.
          example: 0192f7a1-5b10-7c3a-8e21-4d2f8a4c0e0b
      responses:
        '200':
          content:
            text/plain:
              schema:
                type: string
          description: The challenge value, echoed as plain text.
        '422':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: The request does not match the contract.
      security: []
components:
  schemas:
    Problem:
      additionalProperties: false
      description: RFC 9457 problem details; `code` comes from the versioned error catalog.
      properties:
        code:
          title: Code
          type: string
        detail:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          title: Detail
        request_id:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          title: Request Id
        status:
          title: Status
          type: integer
        title:
          title: Title
          type: string
        type:
          default: about:blank
          title: Type
          type: string
      required:
        - title
        - status
        - code
      title: Problem
      type: object

````