Sleeper Transactions API

openapi: 3.1.0
info:
  title: Sleeper Drafts Transactions 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: Transactions
paths:
  /league/{league_id}/transactions/{round}:
    get:
      operationId: getLeagueTransactions
      summary: Get transactions (trades, waivers, free-agent moves) for a week
      tags:
      - Transactions
      parameters:
      - name: league_id
        in: path
        required: true
        schema:
          type: string
      - name: round
        in: path
        required: true
        description: The week/round of transactions.
        schema:
          type: integer
          example: 1
      responses:
        '200':
          description: Array of transaction objects.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Transaction'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/TooManyRequests'
components:
  schemas:
    TradedPick:
      type: object
      properties:
        season:
          type: string
        round:
          type: integer
        roster_id:
          type: integer
          description: Original owner Roster of the pick
        previous_owner_id:
          type: integer
          description: Previous owner roster_id
        owner_id:
          type: integer
          description: Current owner roster_id
    Transaction:
      type: object
      properties:
        transaction_id:
          type: string
        type:
          type: string
          description: trade
          waiver: null
          or free_agent: null
        status:
          type: string
        roster_ids:
          type: array
          items:
            type: integer
        adds:
          type: object
          description: Map of player_id to roster_id
        drops:
          type: object
          description: Map of player_id to roster_id
        draft_picks:
          type: array
          items:
            $ref: '#/components/schemas/TradedPick'
        waiver_budget:
          type: array
          items:
            type: object
        created:
          type: integer
  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.