sql-sanitizer

sql-sanitizer

SQL injection request filter for Express / Fastify / Koa / Nest, with presets, stats/Prometheus, a CI concat scanner, and parameterized sql / sqlQ helpers.

Heuristic middleware is a supplement — always use parameterized queries for real safety.

Install

npm install sql-sanitizer

Quick start (Express)

const express = require('express');
const sqlSanitizer = require('sql-sanitizer');
const { sql } = sqlSanitizer;

const app = express();
app.set('trust proxy', 1);
app.use(express.json());
app.use(sqlSanitizer({
  preset: 'api',
  trustProxy: 1,
  statsRoute: '/__sql-sanitizer/stats',
}));

app.get('/users/:id', async (req, res) => {
  const q = sql`SELECT * FROM users WHERE id = ${req.params.id}`;
  res.json(q);
});

Adapters

// Fastify
fastify.addHook('preHandler', sqlSanitizer.fastify({ preset: 'api' }));
// or: await fastify.register(sqlSanitizer.fastifyPlugin({ preset: 'graphql' }));

// Koa
app.use(sqlSanitizer.koa({ preset: 'form' }));

// NestJS (Express adapter)
consumer.apply(sqlSanitizer.nest({ preset: 'api' })).forRoutes('*');

Presets

Preset	Intent
api	Balanced API defaults + rate limit
form	Allows common free-text fields (bio, comment, …)
graphql	Stricter sensitivity for GraphQL bodies

Stats & Prometheus

const mw = sqlSanitizer({ statsRoute: '/__sql-sanitizer/stats', statsToken: 'secret' });
app.use(mw);
// GET /__sql-sanitizer/stats  (header x-sql-sanitizer-token: secret)
// GET /__sql-sanitizer/stats?format=prometheus
mw.prometheus(); // text exposition

CI scanner

npx sql-sanitizer scan .
npx sql-sanitizer scan ./src --json

Exit code 2 when potential unsafe SQL concatenation is found.

Trusted proxy

sqlSanitizer({ trustProxy: false }); // ignore X-Forwarded-For (anti-spoof)
sqlSanitizer({ trustProxy: 1 });     // one proxy hop
sqlSanitizer({ trustProxy: true });  // trust CDN / XFF / CF-Connecting-IP

Examples

See examples/ — Postgres-style, MySQL-style, and before/after demo.

Changelog

See CHANGELOG.md.

License

MIT