Using BetterChess in Claude

The connector gives Claude a real chess engine and the actual geometry of the board. You use it by asking — there is nothing to memorise.

The one rule: never for a live game against a person

Using an engine to choose your moves against a human opponent is cheating. On chess.com and Lichess it is detected and it gets your account closed — the fair play systems look for exactly this pattern, and “I only checked a few moves” is not a defence.

Fine, and what this is built for:

Games against a bot or computer opponent — Chess.com's fair play policy explicitly exempts these.
A game that is already over. Review it, find where it turned.
Any position you are studying, from a book, a puzzle, or your own head.
Openings, tactics, endgames — anything that is not a move you are about to play against someone.

Not fine, and we will not help with it: a live game against another person, anywhere — online, over the board, or correspondence. If you ask Claude for a move in a game against a human, it is instructed to ask who the opponent is and to decline while the answer is a person.

Setup

Use the Claude desktop app — that is where the live coach runs. A connector is saved to your Claude account, so it also shows up on claude.ai and on your phone, but the desktop app is the one you want.

In the desktop app: Settings → Connectors, scroll to the bottom, click Add custom connector.
Name: BetterChess. Remote MCP server URL: https://mcp.betterchess.co
If the dialog shows Advanced settings (OAuth Client ID, Client Secret): leave them empty. BetterChess registers itself; there is nothing to paste there.
Click Add, then Connect. The app opens a BetterChess sign-in page in your web browser. Sign in, or create an account there — it takes a moment — and approve. Then come back to the app.
Back in Claude, start a new conversation. The tools are picked up when a chat starts, not mid-way through one.

That is the whole setup. Nothing installs on your machine, and subscribing later lifts the cap on the connector you already added — you never reconnect it.

If something goes wrong

“Account mismatch — the account signed in to this browser is different from the one used in the Claude Desktop app”: That message is Claude's, not ours, and it is about your two Claude accounts — it has nothing to do with your BetterChess account. When you click Connect, the desktop app hands the sign-in to your web browser. If the browser is signed in to a different Claude account than the app (work in one, personal in the other), Claude refuses to attach the connector across the two. BetterChess never even saw the request.

Fix: in your web browser, go to claude.ai and sign in with the same Claude account the desktop app uses. Then click Connect in the app again. Nothing changes on the BetterChess side.
“Free users are limited to one custom connector”: Anthropic's limit on the free Claude plan: one custom connector. Remove another one, or upgrade your Claude plan. Not something BetterChess can change.
The connector is listed, but Claude does not use it: Start a new conversation — tools load at the start of a chat. If it still does not, open the tools menu in the chat (the + or sliders icon) and check BetterChess is switched on.
You signed in to the wrong BetterChess account: Settings → Connectors → BetterChess → Disconnect, then Connect again and sign in with the right one. Your subscription follows the BetterChess account, not the Claude account.
Does it matter which BetterChess account I use on which Claude?: No. BetterChess does not check your Claude account at all. One BetterChess account works from any Claude account, any app, any device.

Live coaching while you play a bot

This is the thing in the video on the homepage, and you can run it exactly the same way. Claude watches the board in its own browser, warns you about the captures and checks that lose before you play them, draws the recommendation on the board, and explains every move. Nothing installs.

Open the Claude desktop app and open its built-in browser.
Go to chess.com/play/computer, pick a bot, press Play. Guest is fine — you do not need a chess.com account.
In the chat, pick the coach prompt from the BetterChess connector — or just type:
```
Coach my live chess game against a bot, in the Claude browser.
```

Claude loads the coaching rig into the page, confirms it is a bot game, and starts. From then on: it waits for the board, analyses your position, draws the move, and tells you why. Press H or the Ask coach button any time to ask about the position. Ask “what about Ng5?” and it tells you what that walks into.

Install the live-coach skill (recommended)

The coach prompt above works on its own. The skill makes it reliable: it tells Claude exactly how to run the loop — arm the rig once, read the board from the page, never stop to ask “say go”, never fall back to a local engine, and explain theplan behind each move (a trade that removes their attacker, a sacrifice and what it buys, a real material win) rather than just naming it.

Claude app: download chess-live-coach-skill.zip. In Claude, open Settings → Capabilities → Skills → Upload skill, pick the zip, and make sure it is switched on.
Cowork / Claude Code: run /plugin marketplace add yuvalsuede/betterchess-connector and then /plugin install betterchess@betterchess. The plugin includes the connector and the skill.
Open a bot game in the Claude desktop app's browser and type coach me. Claude should say which game it is coaching and, after your first move, draw on the board.

Bot games only. If the page is a game against a person, Claude refuses before the first analysis — it reads the page, not what you tell it. Desktop app only for now: the loop needs Claude's own browser, which the web and mobile apps do not have.

What to ask

There are no commands. Ask in plain language and Claude picks the right tool. These work as-is:

Analyse a position

Here is my position: rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2. What is undefended, what attacks it, and what are the best moves?

Runs chess_analyse. You get the top moves with real evaluations, whose turn it is, whether that side is in check, undefended pieces and what attacks them, and the material balance.

Check one piece's reach

In that position, exactly which squares does the knight on f3 attack?

Runs chess_attacks. This is the one that stops confident nonsense about knights, pins and discovered attacks — the squares are computed, not recalled.

Review a finished game

Here is my PGN from a game I just finished. Where did I actually lose it? [paste PGN]

Runs chess_review (Pro). It replays the game and reports only the moves where the evaluation genuinely swung — the two moves that decided it, not forty small inaccuracies.

Sanity-check a move you are considering

I am studying this position and I want to play Ng5. Is that actually good, or is there a refutation? [paste FEN]

Analyses the position after your move, so you get the concrete refutation rather than an opinion. Use this while studying — not mid-game against a person.

What the connector actually gives Claude

Tool	Returns	Plan
`chess_analyse`	Top moves with evaluations, side to move, check, undefended pieces and their attackers, material balance.	Free (daily budget)
`chess_attacks`	The exact squares a given piece attacks, and its type and colour.	Free (daily budget)
`chess_review`	Every move in a finished game where the evaluation swung past a threshold, with the move played, the better move, and the position after.	Pro

Getting better answers

Paste the position. A FEN, a PGN, or the moves so far. Describing it in words means Claude has to reconstruct it, and that is where mistakes come from.
Ask why, not just what. “What is the best move” gets you a move. “Why is that better than the obvious capture” gets you the thing that transfers to your next game.
Push back. If an explanation does not add up, say so and ask it to re-check against the board. The tools are there to be re-run.
Name your mistake. “I keep hanging pieces in the opening — go through this game and show me where” is a much better prompt than “review this game”.

Frequently asked

Do I need to install anything?

No. Paste the connector URL into Claude's connector settings and sign in with your BetterChess account. There is no terminal step, no config file and no local Stockfish. It works on the free Claude plan and on mobile.

Is there a /coach command?

There is a coach prompt in the connector, and a chess-live-coach skill you can install (download it from this page, or install the BetterChess plugin in Cowork / Claude Code). With the skill on, saying "coach me" with a bot game open is enough.

Can I use it while I am playing someone?

No. Using an engine to pick moves against a human opponent is cheating and will get your account banned on chess.com and Lichess. Against a bot, in a finished game, or on a position you are studying, it is fine — see the fair play section above.

What is the free limit?

A free account gets a daily analysis budget, which is enough to work through a game or study positions. Pro removes the cap for $5.99/month, cancel anytime.

Does Claude ever guess?

The board facts do not. Attackers, defenders, evaluations and legal moves are computed by the engine and handed to Claude as fact. Claude still writes the explanation around them, so if it ever says something that contradicts the numbers it returned, tell it — it will re-check.

Which position formats work?

FEN, PGN, or a plain list of moves from the start (e.g. e4 e5 Nf3 Nc6). Paste whichever you have.

Questions or something not working: info@betterchess.co. BetterChess is independent and not affiliated with Chess.com, Lichess or Anthropic; those names are their owners' trademarks. BetterChess is a practice tool — we make no guarantee of any rating result.

PRINTED CHESS PUZZLE CARDS