Remote MCP and OAuth
A client must support the endpoint transport and complete OAuth. Accepting a URL is not proof that authorization or tool calls work.
Yahoo Fantasy API, no code needed
A hosted Yahoo Fantasy MCP server
League Loom is a free, hosted, read-only Yahoo Fantasy MCP server.
Skip registering a Yahoo developer app and handling OAuth refresh: add https://leagueloom.com/mcp to Claude, ChatGPT or another MCP client on a computer, sign in with Yahoo in setup, and use the same tools as ESPN, Sleeper and Fantrax. Claude's phone app can then use it.
Free connector · ESPN, Sleeper, Fantrax & Yahoo · Works with compatible AI tools
Looking for plain setup steps instead? See Connect Yahoo Fantasy to ChatGPT and Claude.
Looking for the Claude-only walkthrough? See Connect Yahoo Fantasy to Claude.
Last updated
Before you start
Check your client and Yahoo access
A Yahoo sign-in in setup
Sign in with the Yahoo account that manages your team. League Loom lists that account's current-season leagues.
Data varies by league
Football, basketball, baseball and hockey leagues are supported. A field Yahoo does not return stays unavailable rather than becoming a made-up value.
Get connected
From your league to your AI tool
1
Add the connector
In Claude or any MCP tool, add a custom connector; in ChatGPT on the web, turn on developer mode and use the + button on the Plugins page. Give it a name and paste the League Loom URL as the server address.
2
Choose your leagues
Load your leagues in the setup wizard. Select a personal team for team-specific help, or leave it unselected for league overviews. No API keys.
3
Just ask
Ask about your roster, waivers, matchups, and more, in plain language, across every league.
Remote connector URL
https://leagueloom.com/mcpAdd this URL in your AI tool, then follow the guided setup.
On your phone? Send yourself this setup link to finish on a computer.
Worked example
Verify one complete retrieval
A reproducible integration checklist, not a fabricated live response.
Discover and authorize
Add https://leagueloom.com/mcp in your client and complete OAuth. In setup, choose Yahoo, sign in, select a league and team, and return to the assistant.
Read the configured profile
Ask for your connected setup. The fantasy_get_my_setup result should list the expected Yahoo league before the assistant asks for a roster.
Read one team
Ask for your Yahoo team. Check the reported league, roster and lineup period. A successful handshake alone does not verify Yahoo access.
Resolve the correct failure
An OAuth failure happens before Yahoo is called. A Yahoo authorization error means the sign-in needs renewing in setup. A missing field is a coverage gap, not evidence of an empty team.
More about this connection
MCP transport, OAuth authorization and Yahoo data access are separate checks. League Loom is hosted, so there is no server to deploy, no Yahoo developer app to register and no refresh logic to write.
Your client authorizes with League Loom over OAuth; during setup you sign in with Yahoo, and League Loom asks Yahoo for read-only Fantasy Sports access. The long-lived Yahoo refresh token is sealed into your connection token, and short-lived access tokens stay in memory.
The tools that serve a Yahoo league are fantasy_list_providers, fantasy_get_my_setup, fantasy_list_user_leagues, fantasy_get_league_info, fantasy_get_rosters, fantasy_get_standings, fantasy_get_matchups, fantasy_get_draft, fantasy_get_available_players, fantasy_get_my_team, fantasy_analyze_trade, fantasy_get_my_teams, fantasy_get_my_players, fantasy_get_league_health, fantasy_get_transactions, fantasy_get_weekly_digest, fantasy_share_league_page. Not available for Yahoo: fantasy_get_player_data, fantasy_get_schedule, fantasy_get_trending_players. Current tools retrieve or analyze data without submitting moves.
Before you connect
Questions, answered
Do I need to register a Yahoo developer app?
No. League Loom has its own Yahoo app and handles the Yahoo sign-in and token refresh. You add one connector URL, sign in with Yahoo in setup and choose your teams. There is no consumer key, secret or callback URL for you to manage.
How does Yahoo sign-in work?
Yahoo uses OAuth with read-only Fantasy Sports access. You sign in on Yahoo's own page, so League Loom never sees your Yahoo password. The refresh token Yahoo returns is sealed into your connection token, and access tokens are kept only in memory. If Yahoo replaces the refresh token, League Loom stores the newer one encrypted for up to 400 days, located by a one-way hash rather than your name or account. No Yahoo write access is requested.
Which tools work with a Yahoo league?
fantasy_list_providers, fantasy_get_my_setup, fantasy_list_user_leagues, fantasy_get_league_info, fantasy_get_rosters, fantasy_get_standings, fantasy_get_matchups, fantasy_get_draft, fantasy_get_available_players, fantasy_get_my_team, fantasy_analyze_trade, fantasy_get_my_teams, fantasy_get_my_players, fantasy_get_league_health, fantasy_get_transactions, fantasy_get_weekly_digest, fantasy_share_league_page. The capabilities page shows the same support per provider.
What is not available for Yahoo?
fantasy_get_player_data, fantasy_get_schedule, fantasy_get_trending_players do not serve Yahoo leagues, so there is no Yahoo player research, trending list or playoff odds yet. Player projections, keeper costs, salaries and past seasons are not returned either. Transactions are the league's most recent moves, not grouped by week.
Is League Loom an official Yahoo product?
No. League Loom is an independent MCP server that reads Yahoo Fantasy through Yahoo's Fantasy Sports API after you sign in. It is not made or endorsed by Yahoo.
Which AI apps can use it?
Clients that support hosted Streamable HTTP and League Loom's OAuth flow, including Claude, its phone apps once the connector is added, and ChatGPT on the web with developer mode. League Loom is free; your chosen AI service has its own access requirements.
Can it change my Yahoo lineup?
No. League Loom requests read-only access from Yahoo, and no League Loom tool can change your league. You make every move in Yahoo.
Before you connect a league, read how League Loom is built, what the privacy policy says is stored, the terms of service and the full FAQ, or check the press kit with key facts and who builds it.