NATS

NATS Server API

The Server API from NATS — 2 operation(s) for server.

GitHub OpenAPI

Operations 2

GET /varz General server information #
GET /ipqueuesz IP queue sizes #

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/nats/refs/heads/main/openapi/nats-server-api-openapi.yml

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OpenAPI Specification

nats-server-api-openapi.yml Raw ↑ 
openapi: 3.2.0
info:
  title: NATS Monitoring HTTP Accounts Server API
  description: The NATS server exposes a monitoring HTTP endpoint that provides real-time server statistics including connection info, route details, subscription data, JetStream metrics, and health checks for observability and operations.
  version: 2.10.0
  contact:
    name: NATS.io
    url: https://nats.io/
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
- url: http://localhost:8222
  description: Default NATS monitoring endpoint
tags:
- name: Server
paths:
  /varz:
    get:
      summary: General server information
      operationId: getVarz
      tags:
      - Server
      description: Returns general information about the server state including memory, connections, message rates, and configuration.
      responses:
        '200':
          description: Server variables and statistics
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Varz'
  /ipqueuesz:
    get:
      summary: IP queue sizes
      operationId: getIpqueuesz
      tags:
      - Server
      description: Reports sizes of internal IP queues.
      responses:
        '200':
          description: IP queue sizes
          content:
            application/json:
              schema:
                type: object
components:
  schemas:
    Varz:
      type: object
      properties:
        server_id:
          type: string
        server_name:
          type: string
        version:
          type: string
        proto:
          type: integer
        go:
          type: string
        host:
          type: string
        port:
          type: integer
        max_connections:
          type: integer
        max_payload:
          type: integer
        now:
          type: string
          format: date-time
        uptime:
          type: string
        mem:
          type: integer
        cores:
          type: integer
        cpu:
          type: number
        connections:
          type: integer
        total_connections:
          type: integer
        routes:
          type: integer
        remotes:
          type: integer
        leafnodes:
          type: integer
        in_msgs:
          type: integer
        out_msgs:
          type: integer
        in_bytes:
          type: integer
        out_bytes:
          type: integer
        slow_consumers:
          type: integer
        subscriptions:
          type: integer
        jetstream:
          type: object
          properties:
            config:
              type: object
            stats:
              type: object