Linkerd Statistics API

openapi: 3.1.0
info:
  title: Linkerd Proxy Admin Discovery Statistics API
  description: The Linkerd proxy exposes an admin HTTP server on each meshed pod, providing health check endpoints, readiness probes, Prometheus-compatible metrics, and runtime diagnostic information. By default this server listens on port 4191.
  version: 2.x
  contact:
    name: Linkerd
    url: https://linkerd.io/
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
- url: http://localhost:4191
  description: Linkerd proxy admin server (default port)
tags:
- name: Statistics
  description: Resource statistics and golden metrics
paths:
  /api/v1/stat:
    post:
      operationId: getStatSummary
      summary: Linkerd Get stat summary for resources
      description: Returns aggregated metrics (request rate, success rate, latency percentiles) for the specified Kubernetes resources. This powers the linkerd viz stat command. Supports deployments, pods, namespaces, services, replicasets, statefulsets, daemonsets, cronjobs, jobs, and replicationcontrollers.
      tags:
      - Statistics
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/StatSummaryRequest'
      responses:
        '200':
          description: Stat summary response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StatSummaryResponse'
        '500':
          description: Internal server error
components:
  schemas:
    StatSummaryResponse:
      type: object
      properties:
        ok:
          type: object
          properties:
            stat_tables:
              type: array
              items:
                $ref: '#/components/schemas/StatTable'
        error:
          type: object
          properties:
            error:
              type: string
    Resource:
      type: object
      properties:
        namespace:
          type: string
        type:
          type: string
        name:
          type: string
    BasicStats:
      type: object
      properties:
        success_count:
          type: integer
          format: int64
        failure_count:
          type: integer
          format: int64
        latency_ms_p50:
          type: number
          format: double
        latency_ms_p95:
          type: number
          format: double
        latency_ms_p99:
          type: number
          format: double
        actual_success_count:
          type: integer
          format: int64
        actual_failure_count:
          type: integer
          format: int64
    StatTable:
      type: object
      properties:
        pod_group:
          type: object
          properties:
            rows:
              type: array
              items:
                $ref: '#/components/schemas/StatTableRow'
    StatTableRow:
      type: object
      properties:
        resource:
          $ref: '#/components/schemas/Resource'
        time_window:
          type: string
        status:
          type: string
        meshed_pod_count:
          type: integer
        running_pod_count:
          type: integer
        failed_pod_count:
          type: integer
        stats:
          $ref: '#/components/schemas/BasicStats'
        tcp_stats:
          $ref: '#/components/schemas/TcpStats'
    TcpStats:
      type: object
      properties:
        open_connections:
          type: integer
          format: int64
        read_bytes_total:
          type: integer
          format: int64
        write_bytes_total:
          type: integer
          format: int64
    StatSummaryRequest:
      type: object
      properties:
        resource_type:
          type: string
          description: The Kubernetes resource type to query metrics for.
          enum:
          - deployment
          - pod
          - namespace
          - service
          - replicaset
          - statefulset
          - daemonset
          - cronjob
          - job
          - replicationcontroller
        resource_name:
          type: string
          description: Optional specific resource name to filter by.
        namespace:
          type: string
          description: Kubernetes namespace to scope the query.
        time_window:
          type: string
          description: Time window for aggregation (e.g., 1m, 10m, 1h).
          default: 1m
        from_resource_type:
          type: string
          description: Filter by source resource type.
        from_resource_name:
          type: string
          description: Filter by source resource name.
        from_namespace:
          type: string
          description: Filter by source namespace.
        to_resource_type:
          type: string
          description: Filter by destination resource type.
        to_resource_name:
          type: string
          description: Filter by destination resource name.
        to_namespace:
          type: string
          description: Filter by destination namespace.
        tcp_stats:
          type: boolean
          description: Include TCP-level statistics.
      required:
      - resource_type
externalDocs:
  description: Linkerd Proxy Configuration Reference
  url: https://linkerd.io/2-edge/reference/proxy-configuration/