Intlayer LSP Server

The Intlayer Language Server is a Language Server Protocol (LSP) implementation that makes your IDE — and your AI agent — Intlayer-aware. It connects a call like useIntlayer("home") to the .content.ts file that declares it, in both directions.

Features

Two extra behaviours are worth knowing:

• Merged dictionaries — a key split across several content files returns one result per file, so you can navigate to every declaration.
• Monorepo-aware — the server resolves the closest intlayer.config.* to each file, so several projects in one workspace each get their own dictionaries.

Supported calls

The key is read either from a positional string argument or from an options object ({ namespace }, { id }).

This works for every *-intlayer package (next-intlayer, react-intlayer, vue-intlayer, svelte-intlayer, solid-intlayer, preact-intlayer, angular-intlayer, lit-intlayer, express-intlayer, hono-intlayer, fastify-intlayer, intlayer), and for the compat adapter packages that let you keep your existing i18n syntax.

Dictionaries are read from the build output, so run npx intlayer build — or keep your dev server running — to give the server something to resolve.

Installation

The server ships as the intlayer-lsp binary in @intlayer/lsp:

npm install --save-dev @intlayer/lsp

Install it globally instead (npm install -g @intlayer/lsp) if your editor needs intlayer-lsp on the PATH — this is the case for the Claude Code plugin and for any configuration below that calls the binary directly.

Setup

npm install -g @intlayer/lsp

claude plugin marketplace add intlayer@github:aymericzip/intlayer
claude plugin install intlayer-lsp@intlayer

{
  "env": {
    "ENABLE_LSP_TOOL": "1"
  }
}

{
  "lsp": {
    "intlayer-lsp": {
      "binary": {
        "path": "npx",
        "arguments": ["--yes", "@intlayer/lsp"]
      }
    }
  },
  "languages": {
    "TypeScript": { "language_servers": ["intlayer-lsp", "..."] },
    "TSX": { "language_servers": ["intlayer-lsp", "..."] },
    "JavaScript": { "language_servers": ["intlayer-lsp", "..."] },
    "Vue.js": { "language_servers": ["intlayer-lsp", "..."] },
    "Svelte": { "language_servers": ["intlayer-lsp", "..."] }
  }
}

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')

if not configs.intlayer_lsp then
  configs.intlayer_lsp = {
    default_config = {
      -- Launch the server with npx so you don't need a global install
      cmd = { 'npx', '--yes', '@intlayer/lsp' },
      filetypes = {
        'typescript',
        'typescriptreact',
        'javascript',
        'javascriptreact',
        'vue',
        'svelte',
      },
      root_dir = lspconfig.util.root_pattern(
        'intlayer.config.ts',
        'intlayer.config.js',
        'package.json'
      ),
    },
  }
end

lspconfig.intlayer_lsp.setup({})

{
  "languageserver": {
    "intlayer": {
      "command": "npx",
      "args": ["@intlayer/lsp"],
      "filetypes": [
        "typescript",
        "typescriptreact",
        "javascript",
        "javascriptreact",
        "vue",
        "svelte"
      ],
      "rootPatterns": [
        "intlayer.config.ts",
        "intlayer.config.js",
        "package.json"
      ]
    }
  }
}

[language-server.intlayer-lsp]
command = "npx"
args = ["@intlayer/lsp"]

[[language]]
name = "typescript"
language-servers = ["intlayer-lsp", "typescript-language-server"]

[[language]]
name = "tsx"
language-servers = ["intlayer-lsp", "typescript-language-server"]

Note on terminal AI agents

Claude Code acts as a real LSP client — see the tab above.

OpenAI Codex and most other terminal tools are not LSP clients: they read and write files directly. Running the server on its own does not help them; the value comes from having it active in a companion editor whose index the agent can query (Cursor Composer, Windsurf Cascade, Copilot Chat).

How It Works

For each file, the server locates the closest intlayer.config.* and loads that project's configuration to find the compiled dictionaries. Configuration, dictionaries and the source-file list are cached with short TTLs, and invalidated whenever a watched content file changes.

On a request, the server parses the document (via oxc) and inspects the cursor position:

1. On a key string (useIntlayer("home")) → returns every content file declaring that key, positioned on its key: line.
2. On a field usage (content.title, a destructured property, t('path.to.field'), <Trans>, …) → resolves the variable back to its dictionary and returns the matching field inside the content files.
3. From a content file → runs the reverse lookup, scanning project sources for call sites of that key or field.

Troubleshooting

In VS Code, the server logs to View → Output → "Intlayer LSP" — useful to confirm which config was resolved and how many dictionaries were found.