diff --git a/.changeset/fix-windows-acp-paths.md b/.changeset/fix-windows-acp-paths.md
new file mode 100644
index 000000000..16d9f9aa8
--- /dev/null
+++ b/.changeset/fix-windows-acp-paths.md
@@ -0,0 +1,6 @@
+---
+"@moonshot-ai/acp-adapter": patch
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix ACP file reads and edits for Windows workspaces opened through IDE clients.
diff --git a/packages/acp-adapter/src/kaos-acp.ts b/packages/acp-adapter/src/kaos-acp.ts
index 14337d64d..70ed8614f 100644
--- a/packages/acp-adapter/src/kaos-acp.ts
+++ b/packages/acp-adapter/src/kaos-acp.ts
@@ -122,11 +122,12 @@ export class AcpKaos implements Kaos {
     path: string,
     _options?: { encoding?: BufferEncoding; errors?: 'strict' | 'replace' | 'ignore' },
   ): Promise<string> {
+    const rpcPath = this.toClientPath(path);
     try {
-      const resp = await this.conn.readTextFile({ sessionId: this.sessionId, path });
+      const resp = await this.conn.readTextFile({ sessionId: this.sessionId, path: rpcPath });
       return resp.content;
     } catch (err) {
-      throw wrapKaosError(`acp: readTextFile failed for ${path}`, err);
+      throw wrapKaosError(`acp: readTextFile failed for ${rpcPath}`, err);
     }
   }
 
@@ -221,13 +222,19 @@ export class AcpKaos implements Kaos {
   }
 
   private async acpWrite(path: string, content: string): Promise<void> {
+    const rpcPath = this.toClientPath(path);
     try {
-      await this.conn.writeTextFile({ sessionId: this.sessionId, path, content });
+      await this.conn.writeTextFile({ sessionId: this.sessionId, path: rpcPath, content });
     } catch (err) {
-      throw wrapKaosError(`acp: writeTextFile failed for ${path}`, err);
+      throw wrapKaosError(`acp: writeTextFile failed for ${rpcPath}`, err);
     }
   }
 
+  private toClientPath(path: string): string {
+    if (this.inner.pathClass() !== 'win32') return path;
+    return path.replaceAll('/', '\\');
+  }
+
   // ── process execution: delegate to inner ───────────────────────────
 
   exec(...args: string[]): Promise<KaosProcess> {
diff --git a/packages/acp-adapter/test/kaos-acp.test.ts b/packages/acp-adapter/test/kaos-acp.test.ts
index b313f9063..4564f2c6d 100644
--- a/packages/acp-adapter/test/kaos-acp.test.ts
+++ b/packages/acp-adapter/test/kaos-acp.test.ts
@@ -82,7 +82,8 @@ interface MockInnerKaos extends Kaos {
   };
 }
 
-function makeMockInner(): MockInnerKaos {
+function makeMockInner(opts?: { pathClass?: 'posix' | 'win32' }): MockInnerKaos {
+  const pathClass = opts?.pathClass ?? 'posix';
   const spy = {
     pathClassCalls: 0,
     normpathCalls: [] as string[],
@@ -107,7 +108,7 @@ function makeMockInner(): MockInnerKaos {
     osEnv: { os: 'linux', shell: 'bash' } as unknown as Environment,
     pathClass: () => {
       spy.pathClassCalls += 1;
-      return 'posix';
+      return pathClass;
     },
     normpath: (p: string) => {
       spy.normpathCalls.push(p);
@@ -231,6 +232,31 @@ describe('AcpKaos', () => {
         expect((err as Error).message).toContain('rpc died');
       }
     });
+
+    it('uses win32-native separators for ACP file RPC paths', async () => {
+      const conn = makeMockConn({
+        readHandler: async () => ({ content: 'HELLO' }),
+      });
+      const inner = makeMockInner({ pathClass: 'win32' });
+      const kaos = new AcpKaos(conn.asConn(), 's1', inner);
+
+      await kaos.readText('G:/python-code/render_with_mult_gpu/README.md');
+      await kaos.writeText('G:/python-code/render_with_mult_gpu/README.md', 'updated');
+
+      expect(conn.readCalls).toEqual([
+        {
+          sessionId: 's1',
+          path: 'G:\\python-code\\render_with_mult_gpu\\README.md',
+        },
+      ]);
+      expect(conn.writeCalls).toEqual([
+        {
+          sessionId: 's1',
+          path: 'G:\\python-code\\render_with_mult_gpu\\README.md',
+          content: 'updated',
+        },
+      ]);
+    });
   });
 
   describe('readBytes', () => {