Add Custom Arguments setting for Claude sessions

main.js

@@ -1391,6 +1391,16 @@ ipcMain.handle('open-terminal', async (_event, sessionId, projectPath, isNew, se
       let claudeCmd = harness.binary;
       if (cliArgs.length) claudeCmd += ' ' + quoteArgvForShell(shell, cliArgs);
 
+      // customArgs is raw shell too, like preLaunchCmd below: the user's shell
+      // does the quoting, e.g. --settings '{"outputStyle": "Learning"}'
+      if (sessionOptions?.customArgs) {
+        const custom = String(sessionOptions.customArgs);
+        if (/[\r\n]/.test(custom)) {
+          return { ok: false, error: 'customArgs must not contain newlines' };
+        }
+        claudeCmd += ' ' + custom;
+      }
+
       // preLaunchCmd is raw shell by design (e.g. "aws-vault exec profile --") — block newlines only
       if (sessionOptions?.preLaunchCmd) {
         const pre = String(sessionOptions.preLaunchCmd);

projects.js

@@ -1347,7 +1347,7 @@ function legacyScheduleConfig(cli = {}) {
     addDirs: cli['add-dirs'] || '',
     dangerouslySkipPermissions: false,
     worktree: false, worktreeName: '', chrome: false, mcpEmulation: false,
-    preLaunchCmd: '',
+    preLaunchCmd: '', customArgs: '',
     // The old runner passed --model. Effort did not exist, so it is pinned
     // unset rather than picking up a folder default the old run never had.
     model: cli.model || '',

public/session-config.js

@@ -35,6 +35,7 @@
       { key: 'model', label: 'Model', type: 'text', default: '', more: true, placeholder: 'default', suggestions: ['fable', 'opus', 'sonnet'], description: "Blank uses Claude's default. An alias or a full model name" },
       { key: 'effort', label: 'Effort', type: 'select', default: '', more: true, choices: CLAUDE_EFFORTS, description: "Default uses Claude's own setting" },
       { key: 'allowedTools', label: 'Allowed Tools', type: 'text', default: '', more: true, wide: true, description: 'Tools allowed without a permission prompt (comma-separated)' },
+      { key: 'customArgs', label: 'Custom Arguments', type: 'text', default: '', more: true, wide: true, placeholder: `e.g. --settings '{"outputStyle": "Learning"}'`, description: 'Appended to the CLI command, as shell' },
       { key: 'appendSystemPrompt', label: 'Additional System Prompt', type: 'textarea', default: '', more: true, wide: true, description: 'Instructions appended to Claude’s system prompt' },
       { key: 'worktree', label: 'Worktree', type: 'boolean', default: false, description: 'Run each new session in an isolated git worktree' },
       { key: 'worktreeName', label: 'Worktree Name', type: 'text', default: '', placeholder: 'name (optional)' },

test/session-config.test.js

@@ -75,9 +75,9 @@ test('scheduled launches use current folder defaults with only the selected CLI
 
 test('optional settings wait behind More options until they hold a value', () => {
   const empty = SessionConfig.resolveOptions('claude', {}, {});
-  assert.deepEqual(SessionConfig.fieldsBehindMore('claude', empty), ['model', 'effort', 'allowedTools', 'appendSystemPrompt', 'preLaunchCmd', 'addDirs']);
+  assert.deepEqual(SessionConfig.fieldsBehindMore('claude', empty), ['model', 'effort', 'allowedTools', 'customArgs', 'appendSystemPrompt', 'preLaunchCmd', 'addDirs']);
   const filled = SessionConfig.resolveOptions('claude', { preLaunchCmd: 'aws-vault exec prod --' }, { model: 'opus' });
-  assert.deepEqual(SessionConfig.fieldsBehindMore('claude', filled), ['effort', 'allowedTools', 'appendSystemPrompt', 'addDirs'],
+  assert.deepEqual(SessionConfig.fieldsBehindMore('claude', filled), ['effort', 'allowedTools', 'customArgs', 'appendSystemPrompt', 'addDirs'],
     'a saved model and a folder pre-launch command stay in view');
   assert.deepEqual(SessionConfig.fieldsBehindMore('codex', SessionConfig.resolveOptions('codex', {}, {})), ['codexModel', 'codexEffort', 'preLaunchCmd', 'addDirs']);
   assert.ok(!SessionConfig.fieldsBehindMore('claude', empty).includes('permissionMode'), 'the main settings are never tucked away');