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

# Register a webhook subscription (discovery.revision). Deliveries are HMAC-SHA256 signed with the provided secret in the X-Webhook-Signature header.



## OpenAPI

````yaml /openapi/buyer.yaml post /api/v2/buyer/webhook-subscriptions
openapi: 3.1.0
info:
  title: Semicola Exchange buyer API
  version: 2.0.0
  description: >-
    Buyer endpoints: advertisers, storefronts and connections, product
    discovery, campaigns, proposals, media buys, creatives and reporting. Every
    write accepts an Idempotency-Key header.
servers:
  - url: https://api.semicola.com
security:
  - bearerAuth: []
  - sessionCookie: []
tags:
  - name: Advertisers
  - name: Storefronts
  - name: Product Discovery
  - name: Campaigns
  - name: Media Buys
  - name: Creatives
  - name: Catalogs
  - name: Reporting
  - name: Event Sources
  - name: Webhooks
  - name: Tasks
  - name: Audit Logs
  - name: Activity
paths:
  /api/v2/buyer/webhook-subscriptions:
    post:
      tags:
        - Webhooks
      summary: >-
        Register a webhook subscription (discovery.revision). Deliveries are
        HMAC-SHA256 signed with the provided secret in the X-Webhook-Signature
        header.
      operationId: postBuyerWebhookSubscriptions
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                url:
                  type: string
                  maxLength: 2048
                  format: uri
                secret:
                  type: string
                  minLength: 16
                  maxLength: 256
                eventTypes:
                  minItems: 1
                  type: array
                  items:
                    type: string
                    enum:
                      - discovery.revision
              required:
                - url
                - secret
                - eventTypes
              additionalProperties: false
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    anyOf:
                      - type: object
                        properties:
                          subscription:
                            type: object
                            properties:
                              id:
                                type: string
                              url:
                                type: string
                              eventTypes:
                                type: array
                                items:
                                  type: string
                              status:
                                type: string
                                enum:
                                  - active
                                  - inactive
                                  - failed
                              failureCount:
                                type: integer
                                minimum: 0
                                maximum: 9007199254740991
                              lastSuccess:
                                anyOf:
                                  - type: string
                                    format: date-time
                                    pattern: >-
                                      ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
                                  - type: 'null'
                              lastFailure:
                                anyOf:
                                  - type: string
                                    format: date-time
                                    pattern: >-
                                      ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
                                  - type: 'null'
                              createdAt:
                                type: string
                                format: date-time
                                pattern: >-
                                  ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
                              updatedAt:
                                type: string
                                format: date-time
                                pattern: >-
                                  ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
                            required:
                              - id
                              - url
                              - eventTypes
                              - status
                              - failureCount
                              - lastSuccess
                              - lastFailure
                              - createdAt
                              - updatedAt
                            additionalProperties: false
                        required:
                          - subscription
                        additionalProperties: false
                      - type: 'null'
                  error:
                    anyOf:
                      - type: object
                        properties:
                          code:
                            type: string
                          message:
                            type: string
                          field:
                            type: string
                          details: {}
                        required:
                          - code
                          - message
                        additionalProperties: false
                      - type: 'null'
                required:
                  - data
                  - error
                additionalProperties: false
        default:
          description: >-
            Error envelope `{data: null, error: {code, message, field?,
            details?}}`.
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: API key or OAuth access token.
    sessionCookie:
      type: apiKey
      in: cookie
      name: sc_session

````