openapi: 3.0.3
info:
  title: Spring Boot Actuator Application Metrics API
  description: Spring Boot Actuator exposes production-ready management and monitoring endpoints for Spring Boot applications. Endpoints provide health checks, metrics, environment info, configuration properties, thread dumps, and more.
  version: 3.3.0
  contact:
    name: Spring Team
    url: https://spring.io/projects/spring-boot
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
- url: http://localhost:8080/actuator
  description: Default Actuator base path
tags:
- name: Metrics
paths:
  /metrics:
    get:
      operationId: listMetrics
      summary: Spring Boot List available metric names
      tags:
      - Metrics
      responses:
        '200':
          description: List of metric names
          content:
            application/json:
              schema:
                type: object
                properties:
                  names:
                    type: array
                    items:
                      type: string
  /metrics/{metricName}:
    get:
      operationId: getMetric
      summary: Spring Boot Get metric measurements
      tags:
      - Metrics
      parameters:
      - name: metricName
        in: path
        required: true
        schema:
          type: string
        description: Metric name (e.g., jvm.memory.used, http.server.requests)
      - name: tag
        in: query
        required: false
        schema:
          type: array
          items:
            type: string
        description: Tag filter in KEY:VALUE format
      responses:
        '200':
          description: Metric measurements and available tags
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MetricResponse'
        '404':
          description: Metric not found
  /prometheus:
    get:
      operationId: getPrometheus
      summary: Spring Boot Prometheus metrics scrape endpoint
      description: Returns metrics in Prometheus exposition format
      tags:
      - Metrics
      responses:
        '200':
          description: Prometheus metrics
          content:
            text/plain:
              schema:
                type: string
components:
  schemas:
    MetricResponse:
      type: object
      properties:
        name:
          type: string
        description:
          type: string
        baseUnit:
          type: string
        measurements:
          type: array
          items:
            type: object
            properties:
              statistic:
                type: string
                enum:
                - TOTAL
                - TOTAL_TIME
                - COUNT
                - MAX
                - VALUE
                - ACTIVE_TASKS
                - DURATION
              value:
                type: number
        availableTags:
          type: array
          items:
            type: object
            properties:
              tag:
                type: string
              values:
                type: array
                items:
                  type: string