JetBrains IDEs

September 14, 2026 · View on GitHub

Setup guide for using BGforge MLS with JetBrains IDEs (IntelliJ IDEA, WebStorm, CLion, etc.).

Prerequisites
Language server
Syntax highlighting
TypeScript plugins (TSSL/TD)
Settings

Prerequisites

pnpm install -g @bgforge/mls-server

Install LSP4IJ from the JetBrains Marketplace.

Language server

Go to Settings > Languages & Frameworks > Language Servers and add a new server:

Name: BGforge MLS
Command: bgforge-mls-server --stdio

In its Mappings tab, add a file name pattern for each format, with the Language ID set as below. The server dispatches on the language ID, so set it on every mapping.

File name pattern	Language ID
`.ssl`, `.h`	`fallout-ssl`
`*.baf`	`weidu-baf`
`*.d`	`weidu-d`
`.tp2`, `.tpa`, `.tph`, `.tpp`	`weidu-tp2`
`*.slb`	`weidu-slb`
`worldmap.txt`	`fallout-worldmap-txt`
`*.msg`	`fallout-msg`
`*.tra`	`weidu-tra`
`*.2da`	`infinity-2da`
`scripts.lst`	`fallout-scripts-lst`
`weidu.log`	`weidu-log`

Besides the scripting languages, the server answers for MSG and TRA (formatting, outline, folding, parse-error diagnostics), 2DA (formatting, semantic tokens coloring each column), scripts.lst (formatting) and weidu.log (go-to-definition from a mod entry to its .tp2). SLB is served as WeiDU BAF. So is Sword Coast Stratagems SSL (language ID weidu-ssl), which shares the .ssl extension with Fallout SSL - map it per project rather than globally.

Syntax highlighting

Download bgforge-mls-<version>.tmbundle.zip from the latest GitHub release, extract it, then:

Go to Settings > Editor > TextMate Bundles
Click + and point to the extracted bgforge-mls.tmbundle directory

The tmbundle includes grammars for Fallout SSL, WeiDU BAF, WeiDU D and WeiDU TP2, plus Fallout MSG, WeiDU TRA, Infinity 2DA, Fallout Worldmap, Fallout scripts.lst, WeiDU SLB, Sword Coast Stratagems SSL and WeiDU log.

Each grammar declares the extensions and file names from the table above, so installing the bundle maps those files to it. Sword Coast Stratagems SSL declares none, since .ssl goes to Fallout SSL.

Note: .h is also the C and C++ header extension. The *.h mapping above matches by file name alone, so it sends every .h file to the server, C headers included - leave *.h out of the mapping if that is unwanted. The mapping does not change a file's IDE file type. A TextMate grammar highlights only files whose name matches no IDE file type other than plain text, so where Settings > Editor > File Types lists *.h under another file type, .h files keep that type and its highlighting whatever TextMate association you make. Remove *.h from that file type for the association to take effect; the change applies IDE-wide.

TypeScript plugins (TSSL/TD)

If you write .tssl or .td transpiler files, the server package includes TypeScript plugins that run inside tsserver (TypeScript Plugins describes what they do). They load through typescript-language-server added as a second LSP4IJ server, which passes plugins from its initialization options to tsserver:

Install it: pnpm add -g typescript-language-server,typescript@6
In Settings > Languages & Frameworks > Language Servers, add a server named TypeScript (TSSL/TD) with the command typescript-language-server --stdio
In its Mappings tab, add the file name patterns *.tssl and *.td, both with the Language ID typescript
In its Configuration tab (Server sub-tab), paste into Initialization Options, replacing <mls-node-modules> with the node_modules directory holding @bgforge/mls-server:

{
  "plugins": [
    { "name": "@bgforge/mls-server/out/tssl-plugin", "location": "<mls-node-modules>" },
    { "name": "@bgforge/mls-server/out/td-plugin", "location": "<mls-node-modules>" }
  ]
}

name must be a package path as above: tsserver refuses a plugin named by an absolute path. pnpm ls -g --parseable lists that package as <mls-node-modules>/@bgforge/mls-server.

Settings

BGforge MLS uses workspace/configuration. Paste the JSON into the Configuration tab (not Initialization Options) at Settings > Languages & Frameworks > Language Servers > BGforge MLS:

{
  "bgforge": {
    "validate": "saveAndType",
    "falloutSSL": {
      "compilePath": "",
      "compileOptions": "-q -p -l -O2 -d -s -n",
      "outputDirectory": "",
      "headersDirectory": ""
    },
    "weidu": {
      "path": "weidu",
      "gamePath": ""
    }
  }
}

See Settings Reference for all available options.