Fathom Analytics Reports API

openapi: 3.2.0
info:
  title: Fathom Analytics REST Account Reports API
  description: 'Privacy-first, GDPR-compliant, cookie-free website analytics API. Manage sites, events, and milestones; generate aggregated custom reports; and retrieve real-time visitor counts. Authentication uses Bearer token API keys generated in the account settings area.

    '
  version: '1'
  contact:
    name: Fathom Analytics Support
    email: support@usefathom.com
  termsOfService: https://usefathom.com/terms
  license:
    name: Proprietary
servers:
- url: https://api.usefathom.com/v1
  description: Fathom Analytics API v1
security:
- BearerAuth: []
tags:
- name: Reports
  description: Aggregation reports and current visitor counts
paths:
  /aggregations:
    get:
      operationId: getAggregations
      summary: Get aggregations
      description: 'Returns aggregated analytics data. Rate limited to 10 requests per minute. Supports grouping by time period and dimension fields, sorting, filtering, and timezone-aware date ranges.

        '
      tags:
      - Reports
      parameters:
      - name: entity
        in: query
        required: true
        description: The entity type to aggregate.
        schema:
          type: string
          enum:
          - pageview
          - event
      - name: entity_id
        in: query
        required: false
        description: Required when entity is "pageview". The site ID.
        schema:
          type: string
      - name: site_id
        in: query
        required: false
        description: Required when entity is "event". The site ID.
        schema:
          type: string
      - name: entity_name
        in: query
        required: false
        description: Required when entity is "event". The event name.
        schema:
          type: string
      - name: aggregates
        in: query
        required: true
        description: 'Comma-separated list of aggregate metrics. For pageviews: visits, uniques, pageviews, avg_duration, bounce_rate. For events: conversions, unique_conversions, value.

          '
        schema:
          type: string
      - name: date_grouping
        in: query
        required: false
        description: Group results by time period.
        schema:
          type: string
          enum:
          - hour
          - day
          - month
          - year
      - name: field_grouping
        in: query
        required: false
        description: 'Dimension field to group by. Allowed values: hostname, pathname, referrer_hostname, browser, country_code, city, device_type, operating_system, utm_source, utm_medium, utm_campaign, utm_content, utm_term, keyword.

          '
        schema:
          type: string
      - name: sort_by
        in: query
        required: false
        description: Sort order in field:asc or field:desc format.
        schema:
          type: string
      - name: timezone
        in: query
        required: false
        description: IANA TZ database timezone name (e.g. America/New_York).
        schema:
          type: string
      - name: date_from
        in: query
        required: false
        description: Start of date range as Unix timestamp.
        schema:
          type: integer
      - name: date_to
        in: query
        required: false
        description: End of date range as Unix timestamp.
        schema:
          type: integer
      - name: limit
        in: query
        required: false
        description: Maximum number of results to return.
        schema:
          type: integer
      - name: filters
        in: query
        required: false
        description: 'JSON-encoded array of filter objects with field, operator (is, is not, is like, matching, not matching), and value keys.

          '
        schema:
          type: string
      responses:
        '200':
          description: Aggregated analytics results
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AggregationResult'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /current_visitors:
    get:
      operationId: getCurrentVisitors
      summary: Get current visitors
      description: 'Returns the number of visitors currently on a site. Rate limited to 10 requests per minute.

        '
      tags:
      - Reports
      parameters:
      - name: site_id
        in: query
        required: true
        description: The site ID to query.
        schema:
          type: string
      - name: detailed
        in: query
        required: false
        description: If true, returns breakdown by page and referrer.
        schema:
          type: boolean
      responses:
        '200':
          description: Current visitor count and optional detail
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CurrentVisitors'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    Error:
      type: object
      properties:
        error:
          type: string
          description: Human-readable error message.
      required:
      - error
    AggregationResult:
      type: object
      properties:
        data:
          type: array
          items:
            type: object
            additionalProperties:
              type: string
              description: Dynamic keys matching the requested aggregates and groupings.
    CurrentVisitors:
      type: object
      properties:
        total:
          type: integer
          description: Total number of current visitors on the site.
        content:
          type: array
          description: Per-page breakdown (when detailed=true).
          items:
            type: object
            properties:
              pathname:
                type: string
              total:
                type: integer
        referrers:
          type: array
          description: Per-referrer breakdown (when detailed=true).
          items:
            type: object
            properties:
              referrer:
                type: string
              total:
                type: integer
  responses:
    BadRequest:
      description: Bad request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Missing or invalid API key
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: API key generated in account settings at https://app.usefathom.com/api