diff --git a/build.bun.ts b/build.bun.ts
index 0e534189..03810303 100644
--- a/build.bun.ts
+++ b/build.bun.ts
@@ -1,9 +1,15 @@
 #!/usr/bin/env bun
 import { $ } from "bun";
+import { cpSync, mkdirSync } from "node:fs";
 
 // Run TypeScript compiler for type declarations
 await $`tsc`;
 
+// Copy schema.json (tsc is emitDeclarationOnly, Bun.build doesn't emit JSON assets).
+// Needed for the "./schema.json" package export.
+mkdirSync("dist/src/generated", { recursive: true });
+cpSync("src/generated/schema.json", "dist/src/generated/schema.json");
+
 const isDevelopment = Bun.env.NODE_ENV === "development";
 
 // Build all JavaScript/TypeScript files
@@ -25,10 +31,14 @@ function buildJs(
   });
 }
 
+// zod is a peerDependency — keep it external so consumers share a single
+// zod instance (instanceof ZodError / schema.extend() break with duplicate copies).
+const PEER_EXTERNALS = ["@modelcontextprotocol/sdk", "zod"];
+
 await Promise.all([
   buildJs("src/app.ts", {
     outdir: "dist/src",
-    external: ["@modelcontextprotocol/sdk"],
+    external: PEER_EXTERNALS,
   }),
   buildJs("src/app.ts", {
     outdir: "dist/src",
@@ -36,19 +46,19 @@ await Promise.all([
   }),
   buildJs("src/app-bridge.ts", {
     outdir: "dist/src",
-    external: ["@modelcontextprotocol/sdk"],
+    external: PEER_EXTERNALS,
   }),
   buildJs("src/react/index.tsx", {
     outdir: "dist/src/react",
-    external: ["react", "react-dom", "@modelcontextprotocol/sdk"],
+    external: ["react", "react-dom", ...PEER_EXTERNALS],
   }),
   buildJs("src/react/index.tsx", {
     outdir: "dist/src/react",
-    external: ["react", "react-dom", "@modelcontextprotocol/sdk"],
+    external: ["react", "react-dom", ...PEER_EXTERNALS],
     naming: { entry: "react-with-deps.js" },
   }),
   buildJs("src/server/index.ts", {
     outdir: "dist/src/server",
-    external: ["@modelcontextprotocol/sdk"],
+    external: PEER_EXTERNALS,
   }),
 ]);