fix(config): apply replace mode to custom TOML serializers and read the typed request body

Author: elkaix

packages/agent-core-v2/src/app/config/toml.ts

@@ -65,7 +65,7 @@ export function applySectionToToml(
   }
 
   if (toToml !== undefined) {
-    const rawSub = cloneRecord(rawSnake[snakeKey]);
+    const rawSub = mode === 'replace' ? undefined : cloneRecord(rawSnake[snakeKey]);
     const converted = toToml(value, rawSub);
     if (converted === undefined || converted === null) {
       delete rawSnake[snakeKey];

packages/agent-core-v2/test/app/config/config.test.ts

@@ -2659,6 +2659,18 @@ describe('ConfigService replaceSections', () => {
     disposables.dispose();
   });
 
+  it('replace drops omitted keys from a section with a custom TOML serializer', async () => {
+    const seed = ['[loop_control]', 'max_steps_per_turn = 5', 'max_attempts_per_step = 3', ''].join('\n');
+    const { config, disposables, storage } = await createSectionsConfig(seed);
+    await config.replace(LOOP_CONTROL_SECTION, { maxStepsPerTurn: 7 });
+    const onDisk = new TextDecoder().decode(await storage.read('', 'config.toml'));
+    expect(onDisk).toContain('max_steps_per_turn = 7');
+    expect(onDisk).not.toContain('max_attempts_per_step');
+    await config.reload();
+    expect(config.get(LOOP_CONTROL_SECTION)).toEqual({ maxStepsPerTurn: 7 });
+    disposables.dispose();
+  });
+
   it('replace and replaceSections drop keys the new value does not carry from disk', async () => {
     const seed = [
       '[secondary_model]',

packages/agent-gateway/src/routes/config.ts

@@ -70,14 +70,9 @@ export function registerConfigRoutes(app: ConfigRouteHost, core: Scope): void {
         const config = core.accessor.get(IConfigService);
         const registry = core.accessor.get(IConfigRegistry);
         await config.ready;
-        const body = req.body as Record<string, unknown>;
-        const secondaryModel = body['secondary_model'] as
-          | LegacySecondaryModelRequest
-          | null
-          | undefined;
-        const ordinary = { ...body };
-        delete ordinary['secondary_model'];
-        const camelPatch = convertKeysSnakeToCamel(ordinary) as Record<string, unknown>;
+        const { secondary_model: secondaryModel, ...ordinary } = req.body;
+        const converted = convertKeysSnakeToCamel(ordinary);
+        const camelPatch: Record<string, unknown> = isPlainObject(converted) ? converted : {};
         if (camelPatch['yolo'] === true) {
           camelPatch['defaultPermissionMode'] = 'yolo';
         }