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

# Use Next.js or NestJS

If your app only needs a safe server-side proxy around transaction preparation,
the SDK already ships it.

## Use this path when

* you want the API key to stay on the server
* you do not want to wire each prepare route by hand
* you still want browser code to work with wallet handles and prepared results

## Next.js

Create one catch-all route:

```typescript theme={null}
// app/api/swig/[...swig]/route.ts
import { createSwigRouteHandlers } from '@swig-wallet/developer-sdk/next';

export const { POST } = createSwigRouteHandlers();
```

## NestJS

Create one controller mounted at your Swig proxy prefix:

```typescript theme={null}
import { Controller, Post, Req, Res } from '@nestjs/common';
import { createSwigNestHandler } from '@swig-wallet/developer-sdk/nest';
import type { Request, Response } from 'express';

const swigHandler = createSwigNestHandler();

@Controller('swig')
export class SwigController {
  @Post('*')
  handle(@Req() request: Request, @Res() response: Response) {
    return swigHandler(request, response);
  }
}
```

## Routes the helpers cover

The framework helpers cover:

* `POST /wallet/create`
* `POST /prepare`
* `POST /transfer/sol`
* `POST /transfer/spl-token`
* `POST /swap/jupiter`

## Browser-side usage

Once your proxy exists, browser code can use `SwigBrowserClient` and call only
your local app routes:

```typescript theme={null}
import { SwigBrowserClient } from '@swig-wallet/developer-sdk/browser';

const swig = new SwigBrowserClient({ network: 'devnet' });
const wallet = swig.wallets.fromIdpSession(session);

const prepared = await wallet.transfer.sol({
  destination,
  amount: 1_000_000n,
});
```

Then sign the returned prepared payload with the client helpers.

## Server-side requester resolution

If your app does not include `requesterAuthority` in the browser request, the
helpers let you resolve it server-side:

```typescript theme={null}
createSwigRouteHandlers({
  resolveRequesterAuthority: async ({ wallet }) => {
    return wallet?.requesterAuthority ?? lookupRequesterForRole(wallet?.roleId);
  },
});
```

Use this when auth context or role mapping should stay on the server.