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

# Create Webhook

> Register a webhook URL to receive event notifications.

Events:
- trade.executed: Fired when a trade fills or is submitted
- market.resolved: Fired when a market you hold positions in resolves
- price.movement: Fired on >5% price change for markets you hold

Payload includes X-Simmer-Signature header (HMAC-SHA256) if secret is set.
Webhooks auto-disable after 10 consecutive delivery failures.



## OpenAPI

````yaml /openapi.json post /api/sdk/webhooks
openapi: 3.1.0
info:
  title: Simmer API
  description: Agent-native trading infrastructure for prediction markets.
  version: 1.0.0
servers:
  - url: https://api.simmer.markets
security: []
paths:
  /api/sdk/webhooks:
    post:
      tags:
        - sdk-webhooks
      summary: Create Webhook
      description: >-
        Register a webhook URL to receive event notifications.


        Events:

        - trade.executed: Fired when a trade fills or is submitted

        - market.resolved: Fired when a market you hold positions in resolves

        - price.movement: Fired on >5% price change for markets you hold


        Payload includes X-Simmer-Signature header (HMAC-SHA256) if secret is
        set.

        Webhooks auto-disable after 10 consecutive delivery failures.
      operationId: api_create_webhook_api_sdk_webhooks_post
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/WebhookCreateRequest'
        required: true
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/WebhookResponse'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    WebhookCreateRequest:
      properties:
        url:
          type: string
          title: Url
        events:
          items:
            type: string
          type: array
          title: Events
        secret:
          anyOf:
            - type: string
            - type: 'null'
          title: Secret
      type: object
      required:
        - url
        - events
      title: WebhookCreateRequest
      description: Request to register a webhook subscription.
    WebhookResponse:
      properties:
        id:
          type: string
          title: Id
        url:
          type: string
          title: Url
        events:
          items:
            type: string
          type: array
          title: Events
        active:
          type: boolean
          title: Active
        consecutive_failures:
          type: integer
          title: Consecutive Failures
          default: 0
        last_delivery_at:
          anyOf:
            - type: string
            - type: 'null'
          title: Last Delivery At
        created_at:
          type: string
          title: Created At
      type: object
      required:
        - id
        - url
        - events
        - active
        - created_at
      title: WebhookResponse
      description: Response for a single webhook subscription.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError

````