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

# GTFS-Realtime Service Alerts

> Service alerts for a single agency or the regional feed. The transit page says `agency` is optional and `format` is optional.



## OpenAPI

````yaml /openapi/511-transit-openapi.json get /transit/servicealerts
openapi: 3.1.0
info:
  title: 511.org Transit API Reference
  version: docs-snapshot-2026-03-25
  description: >-
    Official-style API reference for the public 511.org transit surface.


    Primary source documents for this reference snapshot:


    - [Transit spec PDF](/511/source/511-transit-spec.pdf)

    - [Overview spec PDF](/511/source/511-overview-spec.pdf)

    - [Data agreement PDF](/511/source/511-data-agreement.pdf)

    - [Pathways PDF](/511/source/511-pathways-stations.pdf)


    Implementation notes:


    - The public transit page and the transit PDF disagree on some
    query-parameter casing.

    - This reference uses the public page casing where the public API currently
    depends on it and calls out mismatches in endpoint descriptions.

    - The transit page currently documents a default limit of 60 requests per
    3600 seconds.
servers:
  - url: https://api.511.org
    description: Official 511.org API origin
security:
  - apiKeyQuery: []
tags:
  - name: Static NeTEx
    description: >-
      Static schedule and network structure endpoints backed by NeTEx content in
      a SIRI `ServiceDelivery` envelope.


      Covers transit spec sections 2.1 through 2.7 plus the Shapes endpoint
      described later in section 2.20.
  - name: Realtime SIRI
    description: >-
      Stop- and vehicle-level monitoring endpoints described in the transit PDF
      as SIRI services.


      This family covers StopTimetable, StopMonitoring, and VehicleMonitoring.
      The transit PDF also documents discontinued or future-looking SIRI
      services around announcements and timetable updates, which are not modeled
      as stable operations here.
  - name: GTFS & Bulk Feeds
    description: >-
      Bulk static GTFS and GTFS-Realtime feed download endpoints.


      The transit PDF also documents GTFS+ support files and historic regional
      feed behavior. Those details are supporting operational notes rather than
      request-by-request API fields.
paths:
  /transit/servicealerts:
    get:
      tags:
        - GTFS & Bulk Feeds
      summary: GTFS-Realtime Service Alerts
      description: >-
        Service alerts for a single agency or the regional feed. The transit
        page says `agency` is optional and `format` is optional.
      parameters:
        - in: query
          name: format
          required: false
          description: Desired response format. JSON is the default when omitted.
          schema:
            type: string
            enum:
              - json
              - xml
            default: json
        - in: query
          name: agency
          required: false
          description: >-
            Optional agency identifier. Use `RG` for the consolidated regional
            feed when supported by the current endpoint behavior.
          schema:
            type: string
      responses:
        '200':
          description: Alerts in JSON, XML, or protobuf depending on format.
          content:
            application/json:
              schema:
                type: object
            application/xml:
              schema:
                type: string
            application/x-protobuf:
              schema:
                type: string
                format: binary
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  responses:
    Unauthorized:
      description: Invalid API key.
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
  securitySchemes:
    apiKeyQuery:
      type: apiKey
      in: query
      name: api_key
      description: 511.org token query parameter.

````