add merging routers recipe

README.md

@@ -131,6 +131,7 @@ export const onError = (payload: OnErrorPayload<typeof router>) => {
 
 - [Validation](/recipes/validation.md)
 - [Authorization](/recipes/authorization.md)
+- [Merging Routers](/recipes/merging-routers.md)
 - [Error Handling](/recipes/error-handling.md)
 - [Error Formatting](/recipes/error-formatting.md)
 

recipes/merging-routers.md

@@ -0,0 +1,47 @@
+# Merging Routers
+
+Writing all API-code in your code in the same file is not a great idea. It's easy to merge routers with other routers.
+
+```ts
+// ~/server/trpc/routes/posts.ts
+export const posts = trpc.router()
+  .mutation('create', {
+    input: z.object({
+      title: z.string(),
+    }),
+    resolve: ({ input }) => {
+      // ..
+      return {
+        id: 'xxxx',
+        ...input,
+      }
+    },
+  })
+  .query('list', {
+    resolve() {
+      // ..
+      return []
+    }
+  })
+```
+
+```ts
+// ~/server/trpc/routes/users.ts
+export const users = trpc.router()
+  .query('list', {
+    resolve() {
+      // ..
+      return []
+    }
+  })
+```
+
+```ts
+// ~/server/trpc/index.ts
+import { users } from './routes/users'
+import { posts } from './routes/posts'
+
+export const router = trpc.router()
+  .merge('user.', users) // prefix user procedures with "user."
+  .merge('post.', posts) // prefix post procedures with "post."
+```