Server registry & configuration

A language key resolves to a launcher through the Servers registry — a plain map[string]LanguageServer:

type LanguageServer struct {
    Lang        string   // canonical key ("latex", "go", …)
    Binary      string   // default executable name
    Args        []string // extra CLI arguments
    EnvOverride string   // env var that, if set to an existing file, wins
}

Servers is initialised to DefaultServers(). You can mutate it, extend it, or replace it wholesale before you start serving.

The defaults

DefaultServers() returns a fresh map with these entries:

Key	Binary	Args	Env override
latex	texlab		LSPBRIDGE_TEXLAB
go	gopls	serve	LSPBRIDGE_GOPLS
python	pyright-langserver	--stdio	LSPBRIDGE_PYRIGHT
typescript	typescript-language-server	--stdio	LSPBRIDGE_TS
javascript	typescript-language-server	--stdio	LSPBRIDGE_TS
rust	rust-analyzer		LSPBRIDGE_RUSTANALYZER

The env-override keys use a neutral LSPBRIDGE_* prefix — nothing about the catalogue is tied to a particular host application.

The fake entry

DefaultServers() also includes a fake launcher wired to LSPBRIDGE_FAKE. It resolves only when that variable points at a built cmd/fake-lsp binary, and exists so the integration test can run the full round-trip without any real language server installed. It never resolves in production.

Binary resolution

For a given entry, resolveBinary picks the executable in this order:

1. If EnvOverride is set and the variable names a path that exists, use it.
2. Otherwise exec.LookPath(Binary) on $PATH.
3. If neither resolves, the connection is rejected with 503 and the language is omitted from AvailableLanguages().

So operators can repoint a server without rebuilding the image:

LSPBRIDGE_GOPLS=/opt/toolchains/go/bin/gopls \
LSPBRIDGE_TEXLAB=/usr/local/bin/texlab \
  ./your-server

Adding a language

Extend the defaults in place:

lspbridge.Servers["zig"] = lspbridge.LanguageServer{
    Lang: "zig", Binary: "zls", EnvOverride: "LSPBRIDGE_ZLS",
}

…or supply a curated registry (e.g. to expose only the servers you ship):

lspbridge.Servers = map[string]lspbridge.LanguageServer{
    "go":   {Lang: "go", Binary: "gopls", Args: []string{"serve"}, EnvOverride: "LSPBRIDGE_GOPLS"},
    "rust": {Lang: "rust", Binary: "rust-analyzer", EnvOverride: "LSPBRIDGE_RUSTANALYZER"},
}

Advertising availability

AvailableLanguages() returns the sorted set of keys whose binary actually resolves on the host. Serve it to your client so the editor enables LSP only where it will work, and falls back to a simpler autocomplete elsewhere.