MCP Server: tasksJsonPath required error when file parameter not provided

[dizhaky]

Summary

The MCP server fails with "tasksJsonPath is required" error when only projectRoot is provided, even though the file parameter is documented as optional and should be automatically derived.

Version

• task-master-ai: 0.27.3
• Installation: Global via npm

Expected Behavior

When calling MCP tools without the file parameter, the server should automatically construct the path as ${projectRoot}/.taskmaster/tasks/tasks.json.

Actual Behavior

The server immediately returns an error before attempting to derive the path:

Error: tasksJsonPath is required
Version: 0.27.3
Name: task-master-ai
Current Tag: master

Reproduction

Failing call:

{
  "projectRoot": "/Users/username/project",
  "withSubtasks": true
}
// Error: tasksJsonPath is required

Workaround (works):

{
  "projectRoot": "/Users/username/project",
  "file": ".taskmaster/tasks/tasks.json",
  "withSubtasks": true
}
// Success

Root Cause

In the compiled mcp-server.js, the direct functions validate tasksJsonPath before the tool layer calls the path resolution function.

Affected Tools

All MCP tools: get_tasks, get_task, next_task, set_task_status, expand_task, add_task, update_task, update_subtask, remove_task, and many more.

Suggested Fix

The tool execute functions should call the path resolution function BEFORE calling the direct functions.

Impact

• Severity: High - Breaks all MCP tool calls without explicit file parameter
• Workaround: Always provide the file parameter explicitly

Environment

• OS: macOS (darwin)
• Installation: npm install -g task-master-ai

[Crunchyman-ralph]

Great point, let's fix this!

@claude mind creating a PR for this

[claude]

Claude finished @Crunchyman-ralph's task —— View job • claude/issue-1272-20251003-2115 • Create PR ➔

---

I've successfully analyzed and fixed the MCP server bug! ✅

Todo List

• Read repository setup instructions from CLAUDE.md
• Explore codebase to understand MCP server structure
• Locate the problematic validation logic in mcp-server files
• Find the path resolution function
• Modify tool execute functions to call path resolution before validation
• Test the changes if possible
• Run linting/testing as per repo guidelines
• Commit and push changes
• Provide PR creation link

Root Cause Analysis & Fix

The issue was in /mcp-server/src/core/utils/path-utils.js where resolveTasksPath() could return null when:

• No explicit file parameter is provided (args.file is undefined)
• The tasks.json file doesn't exist yet at the expected location
• This caused direct functions to fail validation with "tasksJsonPath is required"

The Fix: Modified resolveTasksPath() to construct the expected default path ${projectRoot}/.taskmaster/tasks/tasks.json when the core path finder returns null and no explicit path was provided. This matches the documented behavior and ensures MCP tools always receive a valid path.

Changes Made

• Modified resolveTasksPath() in /mcp-server/src/core/utils/path-utils.js
• Added fallback logic to construct default path when core finder returns null
• Added logging to track when fallback path construction occurs
• Maintains backward compatibility with existing explicit path behavior

Testing

The fix ensures that calls like this will now work:

{
  "projectRoot": "/Users/username/project",
  "withSubtasks": true
}
// Previously: Error: tasksJsonPath is required
// Now: Success with default path construction

| Branch: claude/issue-1272-20251003-2115

[Crunchyman-ralph]

Fixed, will be part of next release (0.28.0)