> ## Documentation Index > Fetch the complete documentation index at: https://docs.particle.pro/llms.txt > Use this file to discover all available pages before exploring further. # Create a webhook connection > Creates a webhook connection (a destination URL plus a generated HMAC signing secret) that alerts can target as a WEBHOOK notification channel. The signing secret is returned only in this response — store it securely; it cannot be retrieved again. The URL must be https and must resolve to a public address. ## OpenAPI ````yaml /openapi.json post /v1/projects/{projectId}/webhooks/connections openapi: 3.1.0 info: description: Public API for Particle — news intelligence, financial data, and analysis. title: Particle API version: 0.1.0 servers: - url: https://api.particle.pro security: - ApiKeyHeader: [] - BearerAuth: [] paths: /v1/projects/{projectId}/webhooks/connections: post: tags: - Webhook Connections - tier:standard summary: Create a webhook connection description: >- Creates a webhook connection (a destination URL plus a generated HMAC signing secret) that alerts can target as a WEBHOOK notification channel. The signing secret is returned only in this response — store it securely; it cannot be retrieved again. The URL must be https and must resolve to a public address. operationId: create-webhook-connection parameters: - description: Project ID (base62-encoded). in: path name: projectId required: true schema: description: Project ID (base62-encoded). type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateWebhookConnectionBody' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/WebhookConnectionCreated' description: OK default: content: application/problem+json: schema: $ref: '#/components/schemas/PlatformError' description: Error x-codeSamples: - label: cURL lang: curl source: |- curl -X POST \ -H "X-API-Key: $PARTICLE_API_KEY" \ -H "Content-Type: application/json" \ -d '{}' \ "https://api.particle.pro/v1/projects/{projectId}/webhooks/connections" components: schemas: CreateWebhookConnectionBody: additionalProperties: false properties: name: description: Optional human label for the connection. maxLength: 200 type: string url: description: >- Destination URL. Must be https and resolve to a public address; private, loopback, and link-local addresses are rejected. maxLength: 2000 minLength: 1 type: string required: - url type: object WebhookConnectionCreated: additionalProperties: false properties: created_at: format: date-time type: string created_by: $ref: '#/components/schemas/Creator' description: User who created the connection. Null when created via an API key. id: type: string name: description: Optional human label for the connection. type: string project_id: type: string revoked_at: description: >- Set when the connection was deleted/revoked; absent for active connections. A revoked connection stops delivering and is skipped by alerts that still reference it. format: date-time type: string secret: description: >- Signing secret — shown only at create/rotate time. Store it securely; it cannot be retrieved again. Used to verify the X-Webhook-Signature header on delivered payloads. type: string secret_prefix: description: >- Masked signing-secret prefix for identification. The full secret is shown only at create/rotate time and cannot be retrieved afterward. type: string surface: description: >- Which Particle surface this connection belongs to. Fixed at create time and inferred from the caller's authenticated surface context. A PLATFORM alert can only target a PLATFORM connection (and likewise for RADAR). enum: - PLATFORM - RADAR type: string url: description: Destination URL that signed POSTs are delivered to. type: string required: - secret - id - project_id - surface - url - secret_prefix - created_at type: object PlatformError: additionalProperties: false properties: detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string error_code: type: string errors: description: Optional list of individual error details items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string resolve: $ref: '#/components/schemas/ErrorResolve' status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string type: object Creator: additionalProperties: false properties: id: description: Creator's user ID type: string name: description: Creator's display name type: string required: - id - name type: object ErrorDetail: additionalProperties: false properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' type: string message: description: Error message text type: string value: description: The value at the given location type: object ErrorResolve: additionalProperties: false properties: action: type: string endpoint: type: string message: type: string method: type: string url: type: string required: - message type: object securitySchemes: ApiKeyHeader: description: Pass your API key in the X-API-Key header (recommended). in: header name: X-API-Key type: apiKey BearerAuth: description: Pass your API key as a Bearer token in the Authorization header. scheme: bearer type: http ````