A chess coach
in every chat.
Connect your CoaChess account to Claude, ChatGPT or Gemini so it knows your courses, your homework and your openings. This takes about two minutes and there is no API key to create.
What you can ask for once it is connected
Ask, instead of clicking
You say
“What homework do I have, and when is it due?”
Reads your real assignments and what you have finished.
You say
“Why is this move played here?”
Explains the plan, the pawn breaks and why the alternative is worse.
You say
“Where are the holes in my repertoire?”
The common replies you have no answer to, worst first.
You say
“Give me a puzzle around 1200 on forks.”
Hands you a real rated puzzle to solve — you play it, not the assistant.
Do you run an academy? There is a separate CoaChess Org server, with its own guide, for coaches and academy staff: schedules, materials, homework and reports.
Open the Org guideStep 1 — the address
Copy your server URL
This is the only value you paste anywhere. It is the CoaChess Player server.
Your courses, homework, schedule, repertoire, puzzles and progress.
https://api.coachess.net/player/mcpYou sign in with the CoaChess account you already have. There is no API key and no password to paste into your assistant. The first time you connect, CoaChess opens its own sign-in page, shows you exactly what the assistant will be allowed to do, and asks you to approve it. You can disconnect at any time from your assistant’s settings.
Step 2 — your assistant
Connect it
Pick your assistant. The URL above is the only value you need.
Claude — web, desktop and mobile
Custom connectors work on Free, Pro, Max, Team and Enterprise plans, and on claude.ai, Claude Desktop and the mobile apps. On Free you can have one custom connector.
- 1Open Customize → Connectorsclaude.ai/customize/connectors
- 2Click “+”, then “Add custom connector”
- 3Paste the URL from step 1, then click “Add”
- 4Sign in to CoaChess and approve the permission screen
- 5In a chat, open the “+” menu → Connectors and turn CoaChess on. Then ask:“What homework do I have this week?”
On Team and Enterprise, an Owner goes first. An Owner adds the connector once under Organization settings → Connectors → Add → Custom → Web. After that each member connects it themselves from Customize → Connectors, so everyone still only sees their own data.
It travels with you. The same connector works in the Claude mobile apps once you have added it, which is handy when you are at the board rather than at a desk.
ChatGPT
MCP servers are added through developer mode, on Pro, Plus, Business, Enterprise and Education plans. Developer mode is available on the web.
- 1Open Settings → Security and login and turn on Developer modeIt is under Security and login, not under Connectors.
- 2Go to chatgpt.com/plugins and click the “+” button
- 3Paste the URL from step 1 and choose OAuthSign in to CoaChess and approve the permission screen.
- 4Your new app appears under “Drafts”
- 5In a chat, choose Developer mode from the “+” menu and select CoaChessThen ask it a question.
It asks before it changes anything. ChatGPT requires confirmation before any tool that writes. You see the exact request before it is sent, and you can approve it once or for the rest of the conversation.
Deep research works too. The server ships the search and fetch pair ChatGPT expects, so it can be used as a research source over your own courses and homework.
Gemini
Gemini supports MCP through the Gemini CLI. One command adds it:
gemini mcp add --transport http coachess https://api.coachess.net/player/mcpOr add it by hand in ~/.gemini/settings.json:
{
"mcpServers": {
"coachess": {
"httpUrl": "https://api.coachess.net/player/mcp"
}
}
}Sign in with /mcp auth coachess. The CLI opens a browser and listens on localhost:7777 for the reply, so run it on a machine with a browser — not over a plain SSH session. Use /mcp to check the connection afterwards.
Worth knowing. The consumer Gemini app does not yet accept custom MCP servers the way Claude and ChatGPT do — the CLI is the supported path today.
Editors, CLIs and everything else
Claude Code
claude mcp add --transport http coachess https://api.coachess.net/player/mcpCursor — ~/.cursor/mcp.json
{"mcpServers":{"coachess":{"url":"https://api.coachess.net/player/mcp"}}}Any stdio client
uvx fastmcp-remote https://api.coachess.net/player/mcpStep 3 — what you are approving
It can only do what you can do
The connector acts as you. Every request is checked against your real CoaChess account, so it can never reach data that is not yours, or do something your account is not allowed to do. This is the exact wording on the approval screen.
It can
- Read your courses, homework, sessions, session feedback, profile, progress reports, imported games and bootcamps
- Read your opening repertoires and where your games left them; create repertoires, add lines to them and change your training limits
- Look up openings, endgames, position ideas, cloud evaluations and videos
- Give you puzzles to solve
It cannot
- Record practice results or submit homework for you
- Change your account, profile or billing
Your progress stays yours. The assistant can hand you a puzzle, but only you can solve it. When you play it, the app records the result. No tool lets an assistant mark work as done on your behalf.
Reference
What the Player server exposes
36 tools, grouped the way you actually work. You never call these by name — your assistant picks the right one from what you asked.
- Orient
- Your profile, your schedule, and where you left off last time
- Learn
- Your courses and chapters, your homework and what is still open
- Repertoire
- Your opening books: lines, coverage, the gaps, and where real games left the book. It can add lines when you agree
- Position
- Why a move is played, what people play here, exact endgame results, cloud evaluations, and videos of the position
- Practice
- One unsolved puzzle at a time, filtered by rating and theme
- Progress
- A progress report over 7/30/90 days, your session feedback from coaches, and your imported games
If something goes wrong
Troubleshooting
“Not found” when you know it exists
That is the permission system answering, not a bug. The item is either not yours or not assigned to you. Check it in the CoaChess app.
It asks you to sign in again
Sessions expire. Remove the connector and add it again. It takes about twenty seconds and no data is lost.
The assistant cannot see the connector
Custom connectors are a paid-plan feature in both Claude and ChatGPT, and in ChatGPT they need developer mode switched on. Also start a NEW chat after adding one.
Visual panels do not appear
Not every client draws them, and mobile apps often do not. The written answer is always complete on its own.
First run
Worth asking on day one
- “What homework do I have this week?”
- “How am I doing this month?”
- “What did my coach say after the last session?”
- “Give me a puzzle and don't tell me the answer.”
It will not do your training for you. That is deliberate. The assistant can explain, find and organise — but the moves have to be yours, or the progress your coach sees would be a lie.
Ready when you are.
Paste the URL into your assistant and ask it the first question.