Prometheus Alertmanager Webhook Events

asyncapi: 2.6.0
info:
  title: Prometheus Alertmanager Webhook Events
  description: >-
    The Prometheus Alertmanager webhook receiver sends HTTP POST requests to
    configured endpoints when alert groups are triggered. Each webhook payload
    contains a group of alerts sharing common routing labels, their annotations,
    firing status, and the external Alertmanager URL. Alertmanager delivers
    webhooks for both firing and resolved alerts, enabling downstream systems
    to react to alert lifecycle events.
  version: v0.28.0
  contact:
    name: Prometheus Project
    url: https://prometheus.io/community/
externalDocs:
  description: Alertmanager Webhook Receiver Documentation
  url: https://prometheus.io/docs/alerting/latest/configuration/#webhook_config
servers:
  webhookReceiver:
    url: '{webhookURL}'
    protocol: https
    description: >-
      The webhook receiver endpoint configured in Alertmanager's webhook_config.
      Alertmanager POSTs alert group payloads to this URL when routing rules
      match.
    variables:
      webhookURL:
        description: The full URL of the webhook receiver endpoint.
channels:
  /{path}:
    description: >-
      Alertmanager sends HTTP POST requests to configured webhook receiver
      URLs when alert groups fire or resolve. The path is determined by the
      webhook receiver URL configuration.
    parameters:
      path:
        description: Path component of the webhook URL as configured.
        schema:
          type: string
    publish:
      operationId: receiveAlertGroup
      summary: Receive alert group notification
      description: >-
        Alertmanager POSTs this payload when a group of alerts fires or
        resolves. The payload includes the alert group's status, group labels,
        common labels, common annotations, and individual alert details.
        Webhook receivers should respond with 2xx to acknowledge receipt.
        Non-2xx responses cause Alertmanager to retry with exponential backoff.
      message:
        $ref: '#/components/messages/AlertGroupMessage'
components:
  messages:
    AlertGroupMessage:
      name: AlertGroupMessage
      title: Alert Group Webhook Payload
      summary: Batch of alerts sharing common group labels from Alertmanager
      description: >-
        The webhook payload sent by Alertmanager when a group of alerts
        transitions to firing or resolving state. Contains all alerts in the
        group, their current status (firing or resolved), and label/annotation
        data aggregated across the group.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AlertGroupPayload'
  schemas:
    AlertGroupPayload:
      type: object
      required:
        - version
        - groupKey
        - status
        - receiver
        - groupLabels
        - commonLabels
        - commonAnnotations
        - externalURL
        - alerts
      description: >-
        The top-level webhook payload from Alertmanager containing a group of
        related alerts and their current firing or resolved state.
      properties:
        version:
          type: string
          description: Webhook payload version. Currently "4".
          example: '4'
        groupKey:
          type: string
          description: >-
            Key identifying this alert group, composed of routing labels and
            their values.
          example: '{alertname="HighCPU"}/{instance="server01"}'
        truncatedAlerts:
          type: integer
          description: >-
            Number of alerts that were truncated from this payload due to the
            max_alerts configuration setting. 0 if no truncation occurred.
          default: 0
        status:
          type: string
          enum:
            - firing
            - resolved
          description: >-
            Whether any alerts in this group are still firing (firing) or
            all have resolved (resolved).
        receiver:
          type: string
          description: The name of the Alertmanager receiver that dispatched this webhook.
          example: webhook-receiver
        groupLabels:
          type: object
          additionalProperties:
            type: string
          description: >-
            The labels used to group these alerts as configured in the routing
            rules. These labels are common to all alerts in the group.
        commonLabels:
          type: object
          additionalProperties:
            type: string
          description: >-
            Labels present on every alert in the group. A superset of
            groupLabels.
        commonAnnotations:
          type: object
          additionalProperties:
            type: string
          description: >-
            Annotations present on every alert in the group. Useful for
            extracting a shared runbook URL or description.
        externalURL:
          type: string
          format: uri
          description: >-
            The external URL configured for this Alertmanager instance. Used
            to construct links back to the Alertmanager web UI.
        alerts:
          type: array
          items:
            $ref: '#/components/schemas/WebhookAlert'
          description: >-
            The list of alerts in this group. Includes both firing and resolved
            alerts depending on Alertmanager configuration.
    WebhookAlert:
      type: object
      required:
        - status
        - labels
        - annotations
        - startsAt
        - endsAt
        - generatorURL
        - fingerprint
      description: An individual alert within a webhook payload.
      properties:
        status:
          type: string
          enum:
            - firing
            - resolved
          description: Current status of this specific alert.
        labels:
          type: object
          additionalProperties:
            type: string
          description: >-
            Identification labels for this alert. Always includes alertname and
            any labels set by the alerting rule and its recording metric.
        annotations:
          type: object
          additionalProperties:
            type: string
          description: >-
            Non-identifying annotations for this alert such as summary,
            description, and runbook_url.
        startsAt:
          type: string
          format: date-time
          description: Timestamp when this alert transitioned to firing state.
        endsAt:
          type: string
          format: date-time
          description: >-
            Timestamp when this alert resolved. Set to a far-future timestamp
            for currently firing alerts.
        generatorURL:
          type: string
          format: uri
          description: >-
            URL to the Prometheus expression browser for the rule that
            generated this alert.
        fingerprint:
          type: string
          description: >-
            SHA256-based fingerprint of the alert's label set, used to
            deduplicate alerts across Alertmanager instances.
          example: b3e4e2c9a5b23e1f