WorkflowFileChanged· .env|.env.local|.envrc

Reload .env on file change

Watches .env, .env.local and .envrc files and writes updated KEY=VALUE pairs to CLAUDE_ENV_FILE when any of them change on disk. Subsequent Bash commands automatically pick up the new values without restarting the session.

Use cases

Reload environment variables after editing .env without restarting Claude Code
Sync .env.local overrides into Claude's Bash environment on the fly
Keep API keys and feature flags up to date during active development

Providers & tags

Claude Code

#env#environment#reload#dotenv#file-watch

settings.json fragment

{
  "hooks": {
    "FileChanged": [
      {
        "hooks": [
          {
            "command": "node $CLAUDE_PROJECT_DIR/.claude/hooks/file-changed-reload-env.mjs",
            "type": "command"
          }
        ],
        "matcher": ".env|.env.local|.envrc"
      }
    ]
  }
}

Script · .claude/hooks/file-changed-reload-env.mjs

#!/usr/bin/env node
// Recharge les variables d'env d'un fichier modifié dans CLAUDE_ENV_FILE (FileChanged)
import { readFileSync, appendFileSync } from 'fs';
import { fileURLToPath } from 'url';

export function run(
  input,
  {
    readFile = readFileSync,
    append = appendFileSync,
    envFile = process.env.CLAUDE_ENV_FILE,
  } = {},
) {
  if (!envFile || input.event === 'unlink') return null;

  try {
    const content = readFile(input.file_path, 'utf8');
    const lines = content
      .split('\n')
      .filter((l) => /^[A-Z_a-z][A-Z_a-z0-9]*=/.test(l) && !l.startsWith('#'));
    for (const line of lines) {
      append(envFile, `export ${line.trim()}\n`);
    }
    return { count: lines.length, message: `[file-changed-reload-env] reloaded ${lines.length} vars from ${input.file_path}\n` };
  } catch (e) {
    return { error: e.message, message: `[file-changed-reload-env] ${e.message}\n` };
  }
}

/* v8 ignore next 5 */
if (process.argv[1] === fileURLToPath(import.meta.url)) {
  const input = JSON.parse(readFileSync(0, 'utf8'));
  const result = run(input);
  if (result?.message) process.stderr.write(result.message);
}