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Gateway Language Server

Flint ships a full language server for Ignition Jython scripts, backed by your live gateway. It knows the actual system.* API exposed by your gateway's installed modules and indexes your project's script library, so completion and navigation reflect your real environment — not a generic Python install.

The language server runs by default whenever a gateway with an API token is selected. It does not require a running Designer.

Prerequisites

Needs a configured gateway with an API token in flint.config.json. The Flint Designer Bridge module must be installed on the gateway. A running Designer is not required. Without a selected gateway and token, the language server stays dormant and Flint falls back to offline completion.

How it works​

The extension bundles the flint-lsp-proxy language server — there is nothing to install. When you select a gateway, the extension launches the proxy over stdio; the proxy forwards language requests to the Flint Designer Bridge module running on the gateway, which parses your scripts with Ignition's own Jython (Python 2.7) parser.

Setup​

  1. Install the Flint Designer Bridge module on your gateway (see Module Installation).
  2. Add the gateway to flint.config.json and point modules.project-scan-endpoint.apiTokenFilePath at a file containing an API token:
{
  "gateways": [
    {
      "id": "my-gateway",
      "host": "gateway.example.com",
      "port": 8043,
      "ssl": true,
      "modules": {
        "project-scan-endpoint": {
          "apiTokenFilePath": "~/.flint/tokens/my-gateway-token.json"
        }
      }
    }
  ]
}
  1. Select the gateway in the Flint status bar. The language server starts automatically.

Getting a token​

The token type depends on your Ignition version:

Ignition versionToken typeHow to get it
8.1.44+Flint bearer tokenAuto-generated by the Flint module. The gateway writes a token file to <dataDir>/modules/flint/gateway/api-token.json on startup — copy it to your workstation, or set the FLINT_GATEWAY_API_TOKEN environment variable on the gateway to supply your own.
8.3.1+Native gateway API tokenCreate an API token in the gateway web interface (Config > Security > API Tokens) and save it to a file referenced by apiTokenFilePath.

The extension detects the gateway version and sends the token with the matching scheme automatically.

Language features​

FeatureBehavior
CompletionPosition-aware. system.* functions from the live gateway's ScriptManager, project script modules, local variables, and Python keywords.
HoverFunction signatures (parameter names) as markdown.
Go to definitionJumps within a file and across files into project script modules.
Find referencesIntra-file, best-effort identifier matching.
DiagnosticsJython syntax errors, reported as you type (source flint-jython).
SymbolsDocument symbols (outline) and workspace symbol search.

If your gateway hosts a single project, the language server selects it automatically; otherwise it uses the project associated with your selected gateway and workspace.

The server restarts automatically when you switch gateways or projects, or change the relevant configuration — no reload required.

Precision limits
  • Hover shows function signatures only — no docstrings, no parameter types or defaults, and no hover for system.* functions.
  • Diagnostics are syntax-only. Undefined names, type errors, and other semantic problems are not reported.
  • Find references is best-effort and limited to the current file.
  • No completion for Java classes, tag paths, Perspective style classes, or view paths.

Settings​

SettingDefaultPurpose
flint.languageServer.enabledtrueTurns the gateway language server on or off. When off, Flint uses the offline/Designer completion providers instead.
flint.languageServer.proxyPath(bundled)Advanced override: absolute path to an external flint-lsp-proxy executable. Leave unset to use the bundled server.
note

Disabling the language server removes hover, go-to-definition, references, and diagnostics — those features exist only on this path. The fallback providers offer completion only. See Completion for how the fallback sources work.