Chess Coach

Evaluates a position with Stockfish and returns the best moves with their lines. 'fen' is the starting position and 'moves' (optional, SAN, in order) a line played from it before the evaluation. If a move is illegal, the response explains why (pinned piece, king in check…).

analyze_position

Telemetry sent by the interactive board itself, not by the assistant: it records on the Chess Coach server the board action (tab opened, lesson opened, question asked, practice answer right or wrong, a failure), the host app's name and version and an error text of up to 200 characters, with a pseudonymous account code. No moves, positions or conversation text. Server logs keep it for 30 days and product analytics for up to 12 months.

board_event

Turns the mistakes from up to 30 of the player's games into exercises: position, side to move, the move that was played and the engine's solution. It takes the most recent games, or those of a period: from_month and to_month (YYYY-MM), narrowed by time_class, color, result, opponent or opening. Included in the 14-day trial of new accounts; otherwise requires an existing entitlement. Uses 1 review per 8 games analyzed (10 games = 2).

training_drills

Saves how the user wants explanations: 'beginner' (default: no notation, plain words and boards), 'intermediate' or 'advanced' (notation and numeric evaluations).

set_explanation_level

Lists a player's finished games on Chess.com or Lichess as a numbered list: date, opponent, rating, result, color, time control and opening. Searches the whole history, not just recent games: filter by month ('2024-03'), opponent, result (win/loss/draw), color (white/black), time control (bullet/blitz/rapid/daily) or opening, and go further back with 'page' (2, 3…). Without a username it uses the saved one. Doesn't use any reviews.

list_games

Shows the player's plan (Trial, Free, Plus or Pro), the days left in the trial, what they have used today and their saved usernames.

my_account

Summarizes the openings a user plays with white and with black, how many games and their score, and points out the weakest ones. Without a username it uses the player's own; with an opponent's username it helps prepare for a game against them.

opening_report

Analyzes up to 30 of the player's games and scores five areas from 0 to 100: blunders, tactics, clock, converting won positions and openings, sorted from weakest to strongest with examples. It takes the most recent games, or those of a period: from_month and to_month (YYYY-MM), narrowed by time_class, color, result, opponent or opening. Included in the 14-day trial of new accounts; otherwise requires an existing entitlement. Uses 1 review per 8 games analyzed (15 games = 2).

player_report

In-depth, move-by-move Stockfish review of one game: accuracy for each side and by phase, every inaccuracy, mistake and blunder with the best move and its line, the turning point, the missed chances and every move evaluated. 'game' is a game id from the game list, a link to any of the player's games (from any date) or 'latest' for the most recent; 'month' (YYYY-MM) speeds up the search. Without 'game' or 'pgn' it returns the player's recent games instead of analyzing. It also accepts a pasted PGN ('pgn') with the user's color. Shows an interactive board with the game, the evaluation graph and a mode to practice the mistakes. Each moment includes 'plain', a description without notation. Uses 1 review (free plan: 1 a day; 14-day trial: 20 a day).

review_game

Verifies and saves the player's own Chess.com or Lichess username, replacing the saved name for that platform. It is meant for the player's own account, for example when they provide it or correct a spelling mistake; researching an opponent doesn't need it, because game and report tools accept any username. A nonexistent username leaves the saved account unchanged.

set_chess_username