From a534a691cc5c820970b6f736f5a497ed637a9abd Mon Sep 17 00:00:00 2001
From: xuyingzhou <xuyingzhou@tuzhanai.com>
Date: Fri, 30 Jan 2026 13:59:07 +0800
Subject: [PATCH 1/2] fix(zod-validator): improve type inference for partial
 schemas

- Remove HasUndefined check from DefaultInput type
- This ensures Hono RPC can correctly infer json parameter type
- Fixes issue where schema.partial() breaks client type inference

Co-Authored-By: Claude <noreply@anthropic.com>
---
 packages/zod-validator/src/index.ts | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/packages/zod-validator/src/index.ts b/packages/zod-validator/src/index.ts
index 28e0030f2..791391b78 100644
--- a/packages/zod-validator/src/index.ts
+++ b/packages/zod-validator/src/index.ts
@@ -52,13 +52,9 @@ type ExtractValidationResponse<VF> = VF extends (value: any, c: any) => infer R
   : never
 
 type DefaultInput<Target extends keyof ValidationTargets, In, Out> = {
-  in: HasUndefined<In> extends true
-    ? {
-        [K in Target]?: [In] extends [ValidationTargets[K]] ? In : InferInput<In, K>
-      }
-    : {
-        [K in Target]: [In] extends [ValidationTargets[K]] ? In : InferInput<In, K>
-      }
+  in: {
+    [K in Target]: [In] extends [ValidationTargets[K]] ? In : InferInput<In, K>
+  }
   out: { [K in Target]: Out }
 }
 

From be82f3b9964b7d1f219507ba6cccf1673c27c45a Mon Sep 17 00:00:00 2001
From: xuyingzhou <xuyingzhou@tuzhanai.com>
Date: Fri, 30 Jan 2026 14:39:18 +0800
Subject: [PATCH 2/2] chore: add changeset for zod-validator type fix
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
---
 .changeset/green-jeans-rhyme.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/green-jeans-rhyme.md

diff --git a/.changeset/green-jeans-rhyme.md b/.changeset/green-jeans-rhyme.md
new file mode 100644
index 000000000..cf0591d04
--- /dev/null
+++ b/.changeset/green-jeans-rhyme.md
@@ -0,0 +1,5 @@
+---
+"@hono/zod-validator": patch
+---
+
+Fix Hono RPC type inference when using zValidator with partial schemas.