Japanese characters are garbled when writing to files in MCP Docker environment

[xiaotiantakumi]

Issue Description

Japanese characters are being corrupted/garbled when writing to files in MCP (Model Context Protocol) Docker environment. This issue occurs across multiple MCP tools, suggesting it's a general MCP Docker environment problem rather than tool-specific.

Steps to Reproduce

1. Start MCP Docker container with Filesystem (Reference) MCP tool
2. Use file writing functionality to write Japanese text (e.g., "こんにちは") to a file
3. Check the content of the created file

Expected Behavior

Japanese characters should be saved correctly in the file

Actual Behavior

Japanese characters appear garbled/corrupted in the saved file

Affected MCP Tools

• Filesystem (Reference) MCP - confirmed
• Notion MCP - also reported to have the same issue
• Likely affects other MCP tools as well

[devznsh]

Hi! @dgageot I’d like to work on this issue. Could you please assign it to me? Thank you!