> ## Documentation Index
> Fetch the complete documentation index at: https://inertiaserver.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Elysia

> Using `inertia-server` with Elysia

Use the Elysia adapter to inject an `inertia` helper into route context.

## Import

```ts theme={null}
import { elysiaAdapter } from "inertia-server/elysia";
```

## Basic setup

Remember to configure your helpers according to the installation guide [installation](/getting-started/installation)

```ts theme={null}
import { Elysia } from "elysia";
import { elysiaAdapter } from "inertia-server/elysia";
import { createHelper } from "./inertia";

const app = new Elysia()
  .use(elysiaAdapter(createHelper))
  .get("/", ({ inertia }) => {
    return inertia.render(homePage({ title: "Dashboard" }));
  });
```

## Setup with flash/session support

If you use `inertia.flash(...)` or `inertia.errors(...)`, provide a flash adapter.
Your session implementation may vary, in the example we are using a pseudo-code
for a simple cookie based sessions.

```ts theme={null}
import { Elysia } from "elysia";
import { elysiaAdapter } from "inertia-server/elysia";
import { createHelper } from "./inertia";
import { sessionStore } from "./session";

const app = new Elysia()
  .derive((ctx) => ({
    sessionId: sessionStore.getSessionId(ctx.request),
  }))
  .use(
    elysiaAdapter(createHelper, (ctx) => ({
      getAll: () => sessionStore.getFlash(ctx.sessionId),
      set: (data) => {
        sessionStore.setFlash(ctx.sessionId, data);
      },
    })),
  )
  .onAfterHandle((ctx) => {
    ctx.set.headers["Set-Cookie"] = sessionStore.createCookieHeader(
      ctx.sessionId,
    );
  });
```

## Route usage

Once attached, `inertia` is available in your handlers:

```ts theme={null}
app.post("/users", ({ inertia }) => {
  inertia.flash("success", "User created");
  return inertia.redirect("/users");
});
```