diff --git a/README.md b/README.md
new file mode 100644
index 0000000..fd616d3
--- /dev/null
+++ b/README.md
@@ -0,0 +1,19 @@
+# @modelcontextprotocol/ext-apps
+
+MCP Extensions Apps SDK.
+
+## Installation
+
+This repo is in flux and isn't published to npm (when it is, we'll probably use the `@modelcontextprotocol/ext-apps` package). Please install it from git for now:
+
+```bash
+npm install git+https://github.com/modelcontextprotocol/ext-apps.git
+```
+
+## Development Notes
+
+### Build tools in dependencies
+
+The build tools (`esbuild`, `tsx`, `typescript`) are in `dependencies` rather than `devDependencies`. This is intentional: it allows the `prepare` script to run when the package is installed from git, since npm doesn't install devDependencies for git dependencies.
+
+Once the package is published to npm with pre-built `dist/`, these can be moved back to `devDependencies`.
diff --git a/package.json b/package.json
index 28a29a7..73ea74e 100644
--- a/package.json
+++ b/package.json
@@ -40,16 +40,16 @@
     "@types/react-dom": "^19.2.2",
     "concurrently": "^9.2.1",
     "cors": "^2.8.5",
-    "esbuild": "~0.19.10",
     "express": "^5.1.0",
-    "prettier": "^3.6.2",
-    "tsx": "^4.20.6",
-    "typescript": "5.7.2"
+    "prettier": "^3.6.2"
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.20.1",
+    "esbuild": "~0.19.10",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "tsx": "^4.20.6",
+    "typescript": "5.7.2",
     "zod": "^3.25 || ^4.0"
   }
 }