Client

Every procedure you register is callable from two places: a browser (or Node) client over HTTP, and an in-process client during SSR. Both share the same router types through InferRouter.

Pick a client

The HTTP client talks to /rpc/** (and /api/auth/** when you enable .auth()). The in-process client skips the network and still sees the caller’s session when you pass request headers.

Create a typed HTTP client

import { createClient } from "@outerjs/sdk";
import type { InferRouter } from "@outerjs/server";
import type { outer } from "./server"; // your BuiltOuter / Outer instance

export const client = createClient<InferRouter<typeof outer>>({
  baseUrl: "http://localhost:3000",
})
  .auth()
  .build();

await client.user.me();
await client.auth.signIn.email({ email, password });

InferRouter<typeof outer> pulls every procedure’s input, output, and errors into the client. Rename a field on the server and the call site turns red.

.auth() on the SDK builder merges a Better Auth client as client.auth. Skip it when your server never called .auth().

Call from another origin

When the frontend and Outer run on different origins, pair the SDK with CORS on the server:

// client
createClient<InferRouter<typeof outer>>({
  baseUrl: "https://api.example.com",
  credentials: "include",
})
  .auth()
  .build();

// server
new Outer({
  db: pglite(),
  cors: { origins: ["https://app.example.com"], credentials: true },
});

Without credentials: "include" on the client, the browser never sends the session cookie. Without cors.credentials: true and an explicit origin list on the server, the browser blocks the response. See new Outer() → CORS and Auth → CORS.

Call procedures during SSR

const server = await new Outer({ db: pglite() }).schema(v1_0).auth({ secret }).start();

// In a Server Component / loader — pass the incoming request headers
const api = server.client(request.headers);
const user = await api.user.me();

Pass a Headers object, or a function that returns them per call, so permissions see the same session as an HTTP request. This path never hits /rpc — useful on Next.js and TanStack Start.

Upload files

Pass a File (or Blob) into a procedure that accepts one — the SDK switches the request to multipart/form-data for you:

await client.file.upload({ file: input.files[0] });

See .files().

Realtime

Async generator procedures yield over SSE. Iterate them with for await:

for await (const event of await client.post.onChange()) {
  console.log(event);
}

See Realtime.

Next steps

• Introduction — build the server this client talks to
• new Outer() — constructor and BuiltOuter.client()
• .procedure() — register endpoints and extract InferRouter
• new Outer() — CORS, rate limits, and health checks
• Next.js / TanStack Start — mount Outer and call client() in SSR