paraglide-messages-mcp

An MCP server that turns AI agents into a parallel translation team for Paraglide JS / inlang messages/{locale}.json files.

The agent calling the tools is the translator. The server makes that safe and fast:

• Validated writes — every translation is checked against the source (placeholders, markup, plural variants) before anything lands on disk; bad items are rejected individually, never the whole batch.

• One agent per locale, in parallel — the translate loop reads and writes only the source and target locale's files, so subagents can translate all locales concurrently without conflicts.

• Fast and offline — direct JSON file access with a stat-validated cache; tool calls cost milliseconds regardless of project size, and no network is ever needed.

• Toolchain-invisible — written files are byte-compatible with the message-format plugin's own output, and external edits (editor, compiler, git) are always picked up.

Quick start

No installation — add this to your .mcp.json (Claude Code) or claude_desktop_config.json:

{
  "mcpServers": {
    "paraglide": {
      "command": "npx",
      "args": [
        "-y",
        "paraglide-messages-mcp",
        "--project",
        "./project.inlang",
        "--translation-style",
        "Concise product UI; informal address; keep brand terms untranslated."
      ]
    }
  }
}

--project is optional: the server finds project.inlang in the working directory (or a single *.inlang directory up to one level deep) by itself. --translation-style is optional but recommended: it gives agents the linguistic brief to use for tone, formality, and terminology instead of deriving style from existing translations.

Then ask your agent to translate — or use the translate_project prompt to translate every locale at once with one subagent per locale.

Related MCP server: SimpleLocalize MCP Server

Tools

Prompts

Read-only state is also exposed as MCP resources (paraglide://project/info, paraglide://locales/{locale}/missing, paraglide://messages/{locale}/{key}), so clients can pin it as context without spending tool calls.

Agent skill

skill/paraglide-translation/ is an optional installable skill in the open Agent Skills format. The skill simply points the agent to the MCP server.

# Codex, via the skills CLI
npx skills add whazeted/paraglide-messages-mcp --skill paraglide-translation -a codex

# Or install from the skill folder URL directly
npx skills add https://github.com/whazeted/paraglide-messages-mcp/tree/main/skill/paraglide-translation -a codex

For other skills-compatible agents, replace codex with that agent's skills CLI target name. You can list the skill before installing:

npx skills add whazeted/paraglide-messages-mcp --list

Compatibility

Requires the standard Paraglide JS setup: the inlang message format plugin with a single message file per locale (any pathPattern location). Other inlang plugins (i18next, next-intl, ICU) and multi-file namespaces are deliberately not supported — see COMPATIBILITY.md for the exact criteria and reasoning.

Performance

A full 10-locale translation run over a 5,000-message project costs ~3 s of server time (M1 Max Mac Studio)— the pipeline is bounded by the agent's translation speed, not the server.

Documentation

• DEVELOPMENT.md — architecture, message format details, validation rules, building, testing, benchmarking, releasing

• COMPATIBILITY.md — supported project setups

License

MIT