> ## Documentation Index > Fetch the complete documentation index at: https://docs.timbal.ai/llms.txt > Use this file to discover all available pages before exploring further. # Attach Channel to Alarm > Attach another notification channel to an alarm, so one condition reaches several destinations (page Slack and email the on-call, say). Accepts the same channel shape as alarm creation: `{ "id": }` to reuse an existing channel, or inline `type` + `config` to create one. Inline channels identical to an existing row are deduped rather than duplicated. Idempotent — re-attaching a channel that is already linked returns `already_linked: true` and changes nothing. Gated by the alarm, not the channel: `alarms.manage` for an org-level alarm, `projects.alarms.manage` on the owner for a project alarm. Channels themselves are org-wide, so a project-scoped caller can point their alarm at any existing channel — attaching one is a routing decision about their alarm, whereas creating or deleting the channel row needs `notification_channels.manage`. ## OpenAPI ````yaml POST /orgs/{org_id}/alarms/{alarm_id}/channels openapi: 3.1.0 info: title: Timbal Platform API description: Public API documentation for the Timbal platform license: name: '' version: 2.0.0 servers: - url: https://api.timbal.ai description: Production - url: https://api.dev.timbal.ai description: Development security: [] tags: - name: ace description: Action Control Engine (ACE) operations - name: alarms description: Metric series and threshold alarms - name: analytics description: Org and project analytics - name: billing description: Subscriptions, usage, and payment-related operations - name: channels description: Delivery channels alarms notify through - name: content description: Re-sign stored content URLs - name: files description: File operations - name: iam description: IAM — actions, roles, users, and authorization introspection - name: k2 description: Knowledge Bases v2 operations - name: orgs description: Organization operations - name: projects description: Project operations - name: runs description: Execution operations - name: templates description: Public project template catalog - name: users description: Authenticated user profile paths: /orgs/{org_id}/alarms/{alarm_id}/channels: post: tags: - alarms summary: Attach a channel to an alarm description: >- Attach another notification channel to an alarm, so one condition reaches several destinations (page Slack and email the on-call, say). Accepts the same channel shape as alarm creation: `{ "id": }` to reuse an existing channel, or inline `type` + `config` to create one. Inline channels identical to an existing row are deduped rather than duplicated. Idempotent — re-attaching a channel that is already linked returns `already_linked: true` and changes nothing. Gated by the alarm, not the channel: `alarms.manage` for an org-level alarm, `projects.alarms.manage` on the owner for a project alarm. Channels themselves are org-wide, so a project-scoped caller can point their alarm at any existing channel — attaching one is a routing decision about their alarm, whereas creating or deleting the channel row needs `notification_channels.manage`. operationId: add_org_alarm_channel parameters: - name: org_id in: path required: true schema: type: string - name: alarm_id in: path required: true schema: type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateChannelReq' examples: New Slack channel: value: type: slack name: oncall-pages config: token: xoxb-1234567890123-1234567890123 channel: C0123456789 Reuse an existing channel: value: id: '13' required: true responses: '200': description: Channel attached content: application/json: schema: $ref: '#/components/schemas/AddAlarmChannelOut' '400': description: Bad request content: application/json: schema: $ref: '#/components/schemas/ErrorMessage' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ErrorMessage' '404': description: Alarm not found content: application/json: schema: $ref: '#/components/schemas/ErrorMessage' security: - bearer_auth: [] components: schemas: CreateChannelReq: type: object description: |- Channel reference embedded in another resource's create body (alarms). Either reuse by `id`, or supply `type` + `config` inline. properties: config: type: object description: Omitted or null when linking by `id` only. id: type: - string - 'null' description: >- Existing `NotificationChannels.id` for this org. When set, `type` / `config` / `name` are ignored. name: type: - string - 'null' type: $ref: '#/components/schemas/NotificationChannelType' AddAlarmChannelOut: type: object required: - channel_id - channel_action - already_linked properties: already_linked: type: boolean description: |- `true` when this channel was already attached, so the call changed nothing. Linking is idempotent — retries must not create duplicates, which would notify the same destination twice per transition. channel_action: $ref: '#/components/schemas/ChannelAction' description: >- How the underlying `NotificationChannels` row was resolved: referenced by `id`, deduped onto an identical existing row, or inserted. channel_id: type: integer format: int64 ErrorMessage: type: object required: - code - message properties: code: type: string description: Machine-readable error code (e.g. `ALREADY_EXISTS`, `BAD_REQUEST`). message: type: string description: Human-readable description. NotificationChannelType: type: string enum: - email - slack ChannelAction: type: string description: How the request was wired to `NotificationChannels`. enum: - linked - reused - created securitySchemes: bearer_auth: type: http scheme: bearer description: >- Timbal API key. Obtain your API key from the Timbal platform settings. See [Authentication](/api-reference/authentication) for more information. ````