MCP server

libretranslate-mcp gives Claude Code, Codex, OpenCode or any other MCP client machine translation through a LibreTranslate instance.

libretranslate-mcp            # stdio: what the MCP client runs
libretranslate-mcp --http     # http://127.0.0.1:3768/mcp (PORT changes the port)
libretranslate mcp start      # the same in the background; stop/status; boot enable to start it at login

Tools

Tool	What for
libretranslate_translate	One text or a list, with auto detection, HTML and alternatives
libretranslate_translate_file	A local document, saved beside the original as <name>.<target><ext>
libretranslate_detect	The candidate languages of a text
libretranslate_languages	The language codes, or the targets of one source
libretranslate_status	Health, whether a key is required, the character limit, the file formats
libretranslate_suggest	Sends a better translation back, when the user asks for it
libretranslate_resources / libretranslate_describe / libretranslate_call	The raw API, operation by operation

• Tools: the curated tools in detail.
• Generic tools: the raw API.

The HTTP mode

• It is stateless and listens on 127.0.0.1 only.
• It refuses a Host that is not loopback, against DNS rebinding.
• GET /health answers { ok, baseUrl, apiKey, version }, apiKey saying whether one is configured.
• POST /shutdown with the token libretranslate mcp start generates closes it; that is how libretranslate mcp stop stops the server, Windows included.

In stdio mode, stdout carries the protocol: the server logs to stderr only.

Errors never carry the API key: every tool error goes through the same masking as the SDK's.