From 5e59eeea3f66b7713a23f4d1bdde31b64c236dbd Mon Sep 17 00:00:00 2001
From: Tianqi Zhang <tianzh@microsoft.com>
Date: Fri, 26 Dec 2025 09:20:26 +0800
Subject: [PATCH] Fix settings validation to properly respect
 additionalProperties: false

---
 packages/cli/src/config/settings-validation.ts | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/cli/src/config/settings-validation.ts b/packages/cli/src/config/settings-validation.ts
index da06cf082e..9cc8763d44 100644
--- a/packages/cli/src/config/settings-validation.ts
+++ b/packages/cli/src/config/settings-validation.ts
@@ -54,9 +54,10 @@ function buildZodSchemaFromJsonSchema(def: any): z.ZodTypeAny {
         }
         shape[key] = propSchema;
       }
-      schema = z.object(shape).passthrough();
+      // Don't apply passthrough() here - we'll determine the behavior below
+      schema = z.object(shape);
     } else {
-      schema = z.object({}).passthrough();
+      schema = z.object({});
     }
 
     if (def.additionalProperties === false) {
@@ -65,6 +66,9 @@ function buildZodSchemaFromJsonSchema(def: any): z.ZodTypeAny {
       schema = schema.catchall(
         buildZodSchemaFromJsonSchema(def.additionalProperties),
       );
+    } else {
+      // Default to passthrough when additionalProperties is not explicitly false
+      schema = schema.passthrough();
     }
 
     return schema;