@aegis-sdk/next

Next.js integration for scanning LLM chat messages against prompt injection attacks.

Part of the Aegis.js prompt injection defense toolkit.

Installation

npm install @aegis-sdk/next @aegis-sdk/core

Quick Start

// app/api/chat/route.ts
import { Aegis } from '@aegis-sdk/core';
import { withAegis } from '@aegis-sdk/next';
import { streamText } from 'ai';
import { openai } from '@ai-sdk/openai';

const aegis = new Aegis({ policy: 'strict' });

export const POST = withAegis(aegis, async (req, safeMessages) => {
  const result = streamText({
    model: openai('gpt-4o'),
    messages: safeMessages,
  });
  return result.toDataStreamResponse();
});

API

withAegis(aegisOrConfig, handler, options?)

Higher-order function that wraps a Next.js App Router route handler. Parses the request body, scans messages through aegis.guardInput(), and passes safe messages to your handler. Returns 403 with violation details if input is blocked.

| Option | Type | Default | Description | |---|---|---|---| | messagesProperty | string | "messages" | Property on the request body to read messages from | | scanStrategy | ScanStrategy | "last-user" | Which messages to scan | | onBlocked | (req, error) => Response | -- | Custom error handler. Return a Response to take over |

Your handler receives (req, safeMessages, { instance, auditLog }).

aegisMiddleware(options?)

Creates a Next.js Edge Middleware function for request-level scanning. Designed for use in middleware.ts at the project root.

// middleware.ts
import { aegisMiddleware } from '@aegis-sdk/next';

const aegisMw = aegisMiddleware({
  aegis: { policy: 'strict' },
  matchRoutes: ['/api/chat', '/api/ai'],
});

export async function middleware(req: Request) {
  return aegisMw(req);
}

export const config = {
  matcher: ['/api/chat/:path*', '/api/ai/:path*'],
};

| Option | Type | Default | Description | |---|---|---|---| | aegis | AegisConfig \| Aegis | {} | Aegis configuration or pre-constructed instance | | matchRoutes | (string \| RegExp)[] | -- | Route patterns to scan. If omitted, all POST requests are scanned | | messagesProperty | string | "messages" | Property on the request body to read messages from | | scanStrategy | ScanStrategy | "last-user" | Which messages to scan | | onBlocked | (req, error) => Response | -- | Custom error handler |

guardMessages(aegis, messages, options?)

Scans messages directly without using withAegis or Edge Middleware. Useful in Server Actions, custom API routes, or WebSocket handlers. Throws AegisInputBlocked if input is blocked.

Re-exports

Aegis, AegisInputBlocked, AegisSessionQuarantined, AegisSessionTerminated, and all core types are re-exported for convenience.

Learn More

• Documentation
• GitHub

License

MIT