openapi: 3.1.0
info:
  title: CWMS Data Basins Forecasts API
  description: The Corps Water Management System (CWMS) Data API provides a RESTful interface for accessing water management data from the U.S. Army Corps of Engineers. This includes time series data, locations, levels, ratings, forecasts, projects, turbines, gates, and water supply information for USACE-managed water resources across the United States.
  version: 3.0.0
  contact:
    name: USACE CWMS Data API Support
    url: https://github.com/USACE/cwms-data-api
  license:
    name: MIT
    url: https://github.com/USACE/cwms-data-api/blob/develop/LICENSE.md
  x-tags:
  - Water Management
  - Federal Government
  - Hydrology
  - Engineering
servers:
- url: https://cwms-data.usace.army.mil/cwms-data
  description: Production CWMS Data API
- url: https://water.usace.army.mil/cwms-data
  description: Water Data Platform
tags:
- name: Forecasts
  description: Forecast instances and specifications
paths:
  /forecast-spec:
    get:
      operationId: getForecastSpecs
      summary: Get Forecast Specifications
      description: Returns forecast specifications available in the CWMS system.
      tags:
      - Forecasts
      parameters:
      - name: office
        in: query
        required: false
        description: Three-character USACE district office code
        schema:
          type: string
      - name: spec-id-mask
        in: query
        required: false
        description: Mask for filtering forecast spec IDs (supports wildcards)
        schema:
          type: string
      - name: designator-mask
        in: query
        required: false
        description: Mask for filtering designators
        schema:
          type: string
      - name: location-mask
        in: query
        required: false
        description: Mask for filtering locations
        schema:
          type: string
      responses:
        '200':
          description: Forecast specifications
          content:
            application/json:
              schema:
                type: object
  /forecast-instance:
    get:
      operationId: getForecastInstances
      summary: Get Forecast Instances
      description: Returns forecast instances with time series data.
      tags:
      - Forecasts
      parameters:
      - name: office
        in: query
        required: false
        description: Three-character USACE district office code
        schema:
          type: string
      - name: name
        in: query
        required: false
        description: Forecast spec name
        schema:
          type: string
      - name: designator
        in: query
        required: false
        description: Forecast designator
        schema:
          type: string
      - name: forecast-date
        in: query
        required: false
        description: Forecast issue date in ISO 8601 format
        schema:
          type: string
      - name: issue-date
        in: query
        required: false
        description: Date forecast was issued in ISO 8601 format
        schema:
          type: string
      responses:
        '200':
          description: Forecast instance data
          content:
            application/json:
              schema:
                type: object
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: JWT Bearer token for authenticated operations (create, update, delete). Obtain a token from the CWMS authorization endpoint.