feat(claude): remove coder_report_task tool call message (#157)

Author: 35C4n0r

README.md

@@ -73,7 +73,7 @@ agentapi server -- goose
 ```
 
 > [!NOTE]
-> When using Codex, Opencode, Copilot, Gemini, Amp or CursorCLI, always specify the agent type explicitly (eg: `agentapi server --type=codex -- codex`), or message formatting may break.
+> When using Claude, Codex, Opencode, Copilot, Gemini, Amp or CursorCLI, always specify the agent type explicitly (eg: `agentapi server --type=codex -- codex`), or message formatting may break.
 
 An OpenAPI schema is available in [openapi.json](openapi.json).
 

lib/httpapi/server.go

@@ -226,7 +226,7 @@ func NewServer(ctx context.Context, config ServerConfig) (*Server, error) {
 	humaConfig.Info.Description = "HTTP API for Claude Code, Goose, and Aider.\n\nhttps://github.com/coder/agentapi"
 	api := humachi.New(router, humaConfig)
 	formatMessage := func(message string, userInput string) string {
-		return mf.FormatAgentMessage(config.AgentType, message, userInput)
+		return mf.FormatAgentMessage(config.AgentType, message, userInput, logger)
 	}
 
 	isAgentReadyForInitialPrompt := func(message string) bool {

lib/msgfmt/message_box.go

@@ -1,6 +1,7 @@
 package msgfmt
 
 import (
+	"log/slog"
 	"strings"
 )
 
@@ -100,3 +101,57 @@ func removeAmpMessageBox(msg string) string {
 	}
 	return formattedMsg
 }
+
+func removeClaudeReportTaskToolCall(msg string, logger *slog.Logger) string {
+	// Remove all tool calls that start with `● coder - coder_report_task (MCP)` till we encounter the next line starting with ●
+	lines := strings.Split(msg, "\n")
+
+	toolCallStartIdx := -1
+	newLineAfterToolCallIdx := -1
+
+	// Store all tool call start and end indices [[start, end], ...]
+	var toolCallIdxs [][]int
+
+	for i := 0; i < len(lines); i++ {
+		line := strings.TrimSpace(lines[i])
+
+		if strings.HasPrefix(line, "● coder - coder_report_task (MCP)") {
+			toolCallStartIdx = i
+		} else if toolCallStartIdx != -1 && strings.HasPrefix(line, "●") {
+			// Store [start, end] pair
+			toolCallIdxs = append(toolCallIdxs, []int{toolCallStartIdx, i})
+
+			// Reset to find the next tool call
+			toolCallStartIdx = -1
+			newLineAfterToolCallIdx = -1
+		}
+		if len(line) == 0 && toolCallStartIdx != -1 && newLineAfterToolCallIdx == -1 {
+			newLineAfterToolCallIdx = i
+		}
+	}
+
+	// Handle the case where the last tool call goes till the end of the message
+	// And a failsafe when the next message is not prefixed with ●
+	if toolCallStartIdx != -1 && newLineAfterToolCallIdx != -1 {
+		toolCallIdxs = append(toolCallIdxs, []int{toolCallStartIdx, newLineAfterToolCallIdx})
+	}
+
+	// If no tool calls found, return original message
+	if len(toolCallIdxs) == 0 {
+		return msg
+	}
+
+	// Remove tool calls from the message
+	for i := len(toolCallIdxs) - 1; i >= 0; i-- {
+		idxPair := toolCallIdxs[i]
+		start, end := idxPair[0], idxPair[1]
+
+		// Capture the tool call content before removing it
+		toolCallContent := strings.Join(lines[start:end], "\n")
+		logger.Info("Removing tool call", "content", toolCallContent)
+
+		lines = append(lines[:start], lines[end:]...)
+	}
+
+	return strings.Join(lines, "\n")
+}

lib/msgfmt/msgfmt.go

@@ -1,6 +1,7 @@
 package msgfmt
 
 import (
+	"log/slog"
 	"strings"
 )
 
@@ -254,6 +255,14 @@ func formatGenericMessage(message string, userInput string, agentType AgentType)
 	return message
 }
 
+func formatClaudeMessage(message string, userInput string, logger *slog.Logger) string {
+	message = RemoveUserInput(message, userInput, AgentTypeClaude)
+	message = removeMessageBox(message)
+	message = removeClaudeReportTaskToolCall(message, logger)
+	message = trimEmptyLines(message)
+	return message
+}
+
 func formatCodexMessage(message string, userInput string) string {
 	message = RemoveUserInput(message, userInput, AgentTypeCodex)
 	message = removeCodexInputBox(message)
@@ -275,10 +284,10 @@ func formatAmpMessage(message string, userInput string) string {
 	return message
 }
 
-func FormatAgentMessage(agentType AgentType, message string, userInput string) string {
+func FormatAgentMessage(agentType AgentType, message string, userInput string, logger *slog.Logger) string {
 	switch agentType {
 	case AgentTypeClaude:
-		return formatGenericMessage(message, userInput, agentType)
+		return formatClaudeMessage(message, userInput, logger)
 	case AgentTypeGoose:
 		return formatGenericMessage(message, userInput, agentType)
 	case AgentTypeAider:

lib/msgfmt/msgfmt_test.go

@@ -2,6 +2,7 @@ package msgfmt
 
 import (
 	"embed"
+	"log/slog"
 	"path"
 	"strings"
 	"testing"
@@ -233,7 +234,7 @@ func TestFormatAgentMessage(t *testing.T) {
 					assert.NoError(t, err)
 					expected, err := testdataDir.ReadFile(path.Join(dir, string(agentType), c.Name(), "expected.txt"))
 					assert.NoError(t, err)
-					assert.Equal(t, string(expected), FormatAgentMessage(agentType, string(msg), string(userInput)))
+					assert.Equal(t, string(expected), FormatAgentMessage(agentType, string(msg), string(userInput), slog.Default()))
 				})
 			}
 		})

lib/msgfmt/testdata/format/claude/remove-task-tool-call/expected.txt

@@ -0,0 +1,39 @@
+● I'll build a snake game for you. Let me start by reporting my
+   progress and creating a task list.
+
+● Now I'll create a complete snake game with HTML, CSS, and
+  JavaScript:
+
+● Write(snake-game.html)
+  ⎿  Wrote 344 lines to snake-game.html
+     <!DOCTYPE html>
+     <html lang="en">
+     <head>
+         <meta charset="UTF-8">
+         <meta name="viewport" content="width=device-width,
+     initial-scale=1.0">
+         <title>Snake Game</title>
+         <style>
+             * {
+                 margin: 0;
+                 padding: 0;
+     … +334 lines (ctrl+o to expand)
+
+● I've built a complete snake game for you! The game is saved
+  at /home/coder/snake-game.html.
+
+  Features:
+  - Classic snake gameplay with smooth controls
+  - Use arrow keys to control the snake
+  - Press SPACE to pause/unpause
+  - Score tracking with increasing difficulty (speed increases
+  every 5 points)
+  - Colorful gradient background and styled UI
+  - Game over screen with restart option
+  - Snake grows when eating food
+  - Collision detection for walls and self-collision
+
+  How to play:
+  Open the HTML file in your web browser and use the arrow keys
+   to move the snake. Collect the red food to grow and increase
+   your score!

lib/msgfmt/testdata/format/claude/remove-task-tool-call/msg.txt

@@ -0,0 +1,72 @@
+> Build a snake game
+
+● I'll build a snake game for you. Let me start by reporting my
+   progress and creating a task list.
+
+● coder - coder_report_task (MCP)(summary: "Building a snake game
+                                 with HTML/CSS/JavaScript", link:
+                                 "", state: "working")
+  ⎿  {
+       "message": "Thanks for reporting!"
+     }
+
+● Now I'll create a complete snake game with HTML, CSS, and
+  JavaScript:
+
+● Write(snake-game.html)
+  ⎿  Wrote 344 lines to snake-game.html
+     <!DOCTYPE html>
+     <html lang="en">
+     <head>
+         <meta charset="UTF-8">
+         <meta name="viewport" content="width=device-width,
+     initial-scale=1.0">
+         <title>Snake Game</title>
+         <style>
+             * {
+                 margin: 0;
+                 padding: 0;
+     … +334 lines (ctrl+o to expand)
+
+● coder - coder_report_task (MCP)(summary: "Snake game created
+                                 successfully at snake-game.html",
+                                 link: "file:///home/coder/snake-ga
+                                 me.html", state: "working")
+  ⎿  {
+       "message": "Thanks for reporting!"
+     }
+
+
+● I've built a complete snake game for you! The game is saved
+  at /home/coder/snake-game.html.
+
+  Features:
+  - Classic snake gameplay with smooth controls
+  - Use arrow keys to control the snake
+  - Press SPACE to pause/unpause
+  - Score tracking with increasing difficulty (speed increases
+  every 5 points)
+  - Colorful gradient background and styled UI
+  - Game over screen with restart option
+  - Snake grows when eating food
+  - Collision detection for walls and self-collision
+
+  How to play:
+  Open the HTML file in your web browser and use the arrow keys
+   to move the snake. Collect the red food to grow and increase
+   your score!
+
+● coder - coder_report_task (MCP)(summary: "Snake game created
+                                 successfully at snake-game.html",
+                                 link: "file:///home/coder/snake-ga
+                                 me.html", state: "working")
+  ⎿  {
+       "message": "Thanks for reporting!"
+     }
+
+
+──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
+> 
+──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
+  ? for shortcuts                                                                                                                                                                            ⧉ In message_box.go
+

lib/msgfmt/testdata/format/claude/remove-task-tool-call/user.txt

@@ -0,0 +1 @@
+Build a snake game