Variable Operations

Variable operations use the Language Server Protocol (LSP) for semantic understanding of your code.

Read Variable

Find the definition and all references of a variable.

radius read-var <file> --var <name>

Example

radius read-var src/auth.ts --var userId

Output

variable: userId
file: /project/src/auth.ts
engine: lsp
occurrences: 4

--- definition (line 5) ---
    2: import { db } from './database';
    3:
    4: export function getUser(id: string) {
>   5:   const userId = id;
    6:   return db.users.find(userId);
    7: }
    8:

--- reference (line 6) ---
    3:
    4: export function getUser(id: string) {
    5:   const userId = id;
>   6:   return db.users.find(userId);
    7: }
    8:

--- reference (line 12) ---
    9: export function validateUser() {
   10:   const user = getUser('123');
   11:   if (user) {
>  12:     console.log(user.userId);
   13:   }
   14: }

Fields

Field	Description
variable	The searched variable name
file	Absolute path to the file
engine	lsp (semantic) or text (fallback)
occurrences	Number of matches found

Engine Fallback

If LSP is unavailable, Radius falls back to text-based search:

engine: text

Text mode uses word-boundary matching but lacks semantic understanding (won't distinguish between variables with the same name in different scopes).

Modify Variable

Rename a variable across all its references.

radius modify-var <file> --from <old-name> --to <new-name>

Example

radius modify-var src/auth.ts --from userId --to customerId

Output

renamed: userId → customerId
engine: lsp
files modified: 1

--- /project/src/auth.ts (4 edits) ---
   5:   const customerId = id;
   6:   return db.users.find(customerId);
  12:     console.log(user.customerId);
  18:   validateCustomerId(customerId);

Behavior

• Uses LSP textDocument/rename for semantic renaming
• Falls back to text-based replacement if LSP unavailable
• Shows warning when using text mode:

warning: text-based replacement was used. Semantic accuracy is not guaranteed. Review changes carefully.

Cross-File Renaming

When LSP supports it, renaming can affect multiple files:

renamed: API_KEY → API_SECRET
engine: lsp
files modified: 3

--- /project/src/config.ts (1 edits) ---
   5: export const API_SECRET = process.env.API_KEY;

--- /project/src/client.ts (2 edits) ---
   3: import { API_SECRET } from './config';
   8:   headers: { 'X-API-Key': API_SECRET }

--- /project/src/server.ts (1 edits) ---
  12:   validateKey(API_SECRET);

LSP Requirements

For semantic operations to work:

1. LSP server installed for the language
2. Extension registered in Radius
3. Server binary in PATH

Check registered servers:

radius lsp list

Supported Languages

Language	Server	Install
TypeScript/JavaScript	typescript-language-server	npm i -g typescript-language-server
Rust	rust-analyzer	rustup component add rust-analyzer
Python	pylsp	pip install python-lsp-server
Go	gopls	go install golang.org/x/tools/gopls@latest

Custom Servers

Configure additional servers in ~/.radius/lsp-servers.json:

{
  "servers": {
    "cpp": {
      "command": "clangd",
      "args": ["--background-index"]
    }
  }
}

See LSP Configuration for details.