--- name: connect-four description: This skill should be used when the user says "来一盘四子棋", "我要玩四子棋", "玩四子棋", "四连棋", "コネクトフォーで遊ぼう", "四目並べ", "play Connect Four", "let's play Connect Four", "start a Connect Four game", or any request in any language to play a game of Connect Four / 四子棋 / 四目並べ. version: 0.1.0 allowed-tools: Bash, TeamCreate, TaskCreate, TaskUpdate, Agent, SendMessage, TeamDelete --- # Connect Four Skill Two AI agents — Blue and Red — play Connect Four on a 6×7 board. You (team-lead) orchestrate the game, display the board after every move, and referee the result. --- ## Step 1 — Prerequisites Check Run this Bash command: ```bash printenv CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS ``` If the output is NOT exactly `1`, output the following message and **stop immediately** (do not proceed to any further steps): ``` ⚠️ Connect Four requires the experimental Agent Teams feature. To enable it, add the following to the "env" section of ~/.claude/settings.json: "CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS": "1" Then restart Claude Code and try again. ``` --- ## Step 2 — Create the Team Call `TeamCreate` with: - `team_name`: `"connect-four"` - `description`: `"Connect Four — Blue vs Red"` --- ## Step 3 — Spawn Both Player Agents (in parallel) In a **single message**, make two Agent tool calls simultaneously: **Call 1 — blue-player:** - `subagent_type`: `"general-purpose"` - `team_name`: `"connect-four"` - `name`: `"blue-player"` - `prompt`: (see **Appendix A** below) **Call 2 — red-player:** - `subagent_type`: `"general-purpose"` - `team_name`: `"connect-four"` - `name`: `"red-player"` - `prompt`: (see **Appendix B** below) --- ## Step 4 — Initialize the Board The board is a **42-character flat string** (6 rows × 7 columns, row-major, top to bottom): - `.` = empty cell - `B` = blue piece - `R` = red piece - Cell index formula: `index = row * 7 + col` (row 0 = top row, row 5 = bottom row; col 0..6 = left..right) - Column numbers shown to users: **1–7** (col_index = column_number − 1) Initial board: `".........................................."` (exactly 42 dots) Render and display the initial empty board to the user (see **Board Rendering** below), then proceed to the game loop. --- ## Step 5 — Game Loop Track these variables: - `board` — the current 42-char board string - `move_count` — starts at 0, increments each move - `current_player` — starts as `"blue-player"` - `current_piece` — starts as `"B"` (blue goes first) - `last_move_description` — starts as `"Game start"` Repeat the following until `game_over`: ### 5a — Send board to current player Call `SendMessage` with: ``` type: "message" recipient: content: BOARD: <42-char board string> TURN: YOUR_PIECE: OPPONENT_PIECE: LAST_MOVE: summary: "Your turn — choose column 1-7" ``` ### 5b — Receive and parse the response The player's reply will arrive automatically. Extract from the content: - `MOVE: N` — the column chosen (1–7) - `BOARD: <42-char string>` — the updated board after placing their piece ### 5c — Validate the move Check: 1. The new board string is exactly 42 characters. 2. The new board has exactly one more occurrence of `current_piece` compared to the old board. 3. All other characters are unchanged. If validation fails, re-send the original board with an error note: ``` ERROR: Your board update was invalid. Please re-read the rules and try again. BOARD: TURN: YOUR_PIECE: OPPONENT_PIECE: LAST_MOVE: ``` ### 5d — Update state and render Set `board` to the new board string. Set `last_move_description` to `"Blue played column N"` or `"Red played column N"`. Increment `move_count`. Render the board for the user (see **Board Rendering** below), including the move description. ### 5e — Check for win After each move, check whether `current_piece` has four in a row anywhere on the board. Use the index formula `board[row*7+col]`. **Horizontal** (4 checks per row, 6 rows = 24 checks): For r = 0..5, c = 0..3: → win if board[r*7+c], board[r*7+c+1], board[r*7+c+2], board[r*7+c+3] are all `current_piece` **Vertical** (3 starting rows per column, 7 columns = 21 checks): For r = 0..2, c = 0..6: → win if board[r*7+c], board[(r+1)*7+c], board[(r+2)*7+c], board[(r+3)*7+c] are all `current_piece` **Diagonal ↘** (down-right, 3 rows × 4 starting cols = 12 checks): For r = 0..2, c = 0..3: → win if board[r*7+c], board[(r+1)*7+c+1], board[(r+2)*7+c+2], board[(r+3)*7+c+3] are all `current_piece` **Diagonal ↙** (down-left, 3 rows × 4 starting cols = 12 checks): For r = 0..2, c = 3..6: → win if board[r*7+c], board[(r+1)*7+c-1], board[(r+2)*7+c-2], board[(r+3)*7+c-3] are all `current_piece` If any check passes → **win detected**, proceed to **Step 6**. ### 5f — Check for draw If `move_count == 42` and no win was detected → **draw**, proceed to **Step 6**. ### 5g — Rotate player Swap: - `current_player`: `"blue-player"` ↔ `"red-player"` - `current_piece`: `"B"` ↔ `"R"` Continue the loop. --- ## Board Rendering To display the board after each move, convert the 42-char string to a visual grid: **Character mapping:** - `.` → `⚪` - `B` → `🔵` - `R` → `🔴` **Format** (output this to the user): ``` 1 2 3 4 5 6 7 +---------------------+ | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 0 (chars 0–6) | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 1 (chars 7–13) | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 2 (chars 14–20) | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 3 (chars 21–27) | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 4 (chars 28–34) | ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ ⚪ | ← row 5 (chars 35–41) +---------------------+ Move N — 🔵 Blue played column 4 Next: 🔴 Red's turn ``` For the initial board, omit the "Move" and "Next" lines and instead print: `🎮 Game started! 🔵 Blue goes first.` --- ## Step 6 — End the Game Display the final board (rendered), then announce the result: - Blue win: `🎉 Game over! 🔵 Blue wins in N moves!` - Red win: `🎉 Game over! 🔴 Red wins in N moves!` - Draw: `🤝 Game over! It's a draw — the board is full!` ### Cleanup Send shutdown requests to both players **in parallel** (single message, two SendMessage calls): ``` SendMessage type="shutdown_request" recipient="blue-player" content="Game over, thanks for playing!" SendMessage type="shutdown_request" recipient="red-player" content="Game over, thanks for playing!" ``` After both shutdown_response messages are received, call `TeamDelete`. --- ## Appendix A — blue-player Prompt Use this verbatim as the `prompt` parameter when spawning `blue-player`: ``` You are blue-player in a Connect Four game, part of team "connect-four". Your piece color is BLUE, represented as the character 'B'. ## Your Role You wait for messages from team-lead. Each message contains the current board state and asks you to make a move. You choose a column, place your piece, and reply with the updated board. ## Board Format The board is a 42-character string (6 rows × 7 columns, row-major, top to bottom). - Index formula: position = row * 7 + col (row 0 = top, row 5 = bottom; col 0 = leftmost, col 6 = rightmost) - Characters: '.' = empty, 'B' = blue piece, 'R' = red piece - Columns are numbered 1–7 for humans (col_index = column_number - 1) ## When You Receive a Message team-lead will send you a message containing lines like: BOARD: <42-char string> YOUR_PIECE: B OPPONENT_PIECE: R Do the following: 1. Parse the 42-character board string carefully. 2. Decide which column (1–7) to play. Use strategic reasoning: - If the opponent has 3 in a row with an open end, block it immediately. - If you have 3 in a row with an open end, complete it for the win. - Otherwise, prefer the center column (4), then adjacent columns. 3. Determine the target cell: scan rows 5 down to 0 in your chosen column (col_index = column - 1). The first '.' you find is where your piece lands. If the entire column is full (no '.'), pick a different column. 4. Replace that '.' with 'B' in the 42-char string. All other characters must remain identical. 5. Double-check: your new board string is exactly 42 characters and contains exactly one more 'B' than the original. ## How to Respond After deciding your move, send a message back to team-lead using SendMessage: type: "message" recipient: "team-lead" content: MOVE: BOARD: summary: "Played column N" ## Important Rules - Never play in a full column (no '.' available). - Your response MUST contain exactly one SendMessage call. - Do not check for wins — team-lead handles that. - Do not ask questions or add commentary — just play your move and reply. - After replying, go idle and wait for the next message from team-lead. - If you receive a shutdown_request, respond with a shutdown_response approving shutdown. ``` --- ## Appendix B — red-player Prompt Use this verbatim as the `prompt` parameter when spawning `red-player`: ``` You are red-player in a Connect Four game, part of team "connect-four". Your piece color is RED, represented as the character 'R'. ## Your Role You wait for messages from team-lead. Each message contains the current board state and asks you to make a move. You choose a column, place your piece, and reply with the updated board. ## Board Format The board is a 42-character string (6 rows × 7 columns, row-major, top to bottom). - Index formula: position = row * 7 + col (row 0 = top, row 5 = bottom; col 0 = leftmost, col 6 = rightmost) - Characters: '.' = empty, 'B' = blue piece, 'R' = red piece - Columns are numbered 1–7 for humans (col_index = column_number - 1) ## When You Receive a Message team-lead will send you a message containing lines like: BOARD: <42-char string> YOUR_PIECE: R OPPONENT_PIECE: B Do the following: 1. Parse the 42-character board string carefully. 2. Decide which column (1–7) to play. Use strategic reasoning: - If the opponent has 3 in a row with an open end, block it immediately. - If you have 3 in a row with an open end, complete it for the win. - Otherwise, prefer the center column (4), then adjacent columns. 3. Determine the target cell: scan rows 5 down to 0 in your chosen column (col_index = column - 1). The first '.' you find is where your piece lands. If the entire column is full (no '.'), pick a different column. 4. Replace that '.' with 'R' in the 42-char string. All other characters must remain identical. 5. Double-check: your new board string is exactly 42 characters and contains exactly one more 'R' than the original. ## How to Respond After deciding your move, send a message back to team-lead using SendMessage: type: "message" recipient: "team-lead" content: MOVE: BOARD: summary: "Played column N" ## Important Rules - Never play in a full column (no '.' available). - Your response MUST contain exactly one SendMessage call. - Do not check for wins — team-lead handles that. - Do not ask questions or add commentary — just play your move and reply. - After replying, go idle and wait for the next message from team-lead. - If you receive a shutdown_request, respond with a shutdown_response approving shutdown. ```