Sleeper Users API

openapi: 3.1.0
info:
  title: Sleeper Drafts Users API
  version: '1.0'
  description: The Sleeper API is a read-only HTTP API that exposes public fantasy sports data — users, leagues, rosters, matchups, transactions, drafts, draft picks, traded picks, and players. It is free to use and requires no API token, because no content can be modified through it. All endpoints are GET requests that return JSON.
  contact:
    name: Sleeper API Docs
    url: https://docs.sleeper.com/
  x-provenance:
    generated: '2026-07-21'
    method: generated
    source: https://docs.sleeper.com/
    note: Authored by the API Evangelist enrichment pipeline from the operations documented at docs.sleeper.com. Sleeper does not publish an OpenAPI; every path, method, and parameter here is transcribed from the public docs.
servers:
- url: https://api.sleeper.app/v1
  description: Sleeper read-only API (v1)
tags:
- name: Users
paths:
  /user/{id_or_username}:
    get:
      operationId: getUser
      summary: Get a user by username or user_id
      description: Retrieve a user object by either their username or their numeric user_id. Returns the user's user_id, username, display_name and avatar.
      tags:
      - Users
      parameters:
      - name: id_or_username
        in: path
        required: true
        description: The Sleeper username or numeric user_id.
        schema:
          type: string
      responses:
        '200':
          description: A user object.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/TooManyRequests'
components:
  schemas:
    User:
      type: object
      properties:
        user_id:
          type: string
        username:
          type: string
        display_name:
          type: string
        avatar:
          type: string
          description: Avatar id; resolve at https://sleepercdn.com/avatars/{avatar}
        metadata:
          type: object
  responses:
    NotFound:
      description: The requested resource was not found.
    TooManyRequests:
      description: Rate limit exceeded — stay under 1000 API calls per minute to avoid IP blocks.