feat: multi-framework adapters (Fastify, Hono, Next.js App Router, Express)

package.json

@@ -10,9 +10,29 @@
   "module": "./dist/index.mjs",
   "exports": {
     ".": {
-      "types": "./index.d.ts",
-      "import": "./dist/index.mjs",
-      "require": "./dist/index.js"
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js",
+      "require": "./dist/index.cjs"
+    },
+    "./express": {
+      "types": "./dist/adapters/express.d.ts",
+      "import": "./dist/adapters/express.js",
+      "require": "./dist/adapters/express.cjs"
+    },
+    "./fastify": {
+      "types": "./dist/adapters/fastify.d.ts",
+      "import": "./dist/adapters/fastify.js",
+      "require": "./dist/adapters/fastify.cjs"
+    },
+    "./hono": {
+      "types": "./dist/adapters/hono.d.ts",
+      "import": "./dist/adapters/hono.js",
+      "require": "./dist/adapters/hono.cjs"
+    },
+    "./next": {
+      "types": "./dist/next.d.ts",
+      "import": "./dist/next.js",
+      "require": "./dist/next.cjs"
     }
   },
   "types": "index.d.ts",
@@ -23,7 +43,7 @@
   "scripts": {
     "build": "tsup",
     "typecheck": "tsc --noEmit",
-    "test": "node --import tsx --test test/*.test.js"
+    "test": "node --import tsx --test test/*.test.js test/adapters/*.test.js"
   },
   "repository": {
     "type": "git",

src/adapters/express.ts

@@ -0,0 +1,25 @@
+import monitor, {
+  getMetrics,
+  resetMetrics,
+  metricsHandler,
+  prometheusHandler,
+  dashboardHandler,
+  exportHAR,
+  replayRequest,
+  generateCurl,
+} from '../../index.ts';
+
+export {
+  monitor as expressLens,
+  monitor,
+  getMetrics,
+  resetMetrics,
+  metricsHandler,
+  prometheusHandler,
+  dashboardHandler,
+  exportHAR,
+  replayRequest,
+  generateCurl,
+};
+
+export default monitor;

src/adapters/fastify.ts

@@ -0,0 +1,105 @@
+import store from '../store.ts';
+import { redactHeaders, generateCurl } from '../utils.ts';
+import { getDashboardHTML } from '../dashboard.ts';
+import type { ExpressLensOptions } from '../middleware.ts';
+
+/**
+ * Fastify plugin adapter for Express Lens HTTP monitoring and debugging.
+ */
+export function fastifyExpressLens(options: ExpressLensOptions = {}) {
+  const slowThresholdMs = options.slowThresholdMs != null ? options.slowThresholdMs : 500;
+  const customRedactList = Array.isArray(options.redactHeaders) ? options.redactHeaders : [];
+
+  return async function expressLensPlugin(fastify: any) {
+    const requestTimes = new WeakMap<any, number>();
+
+    // 1. Hook into onRequest to record start time
+    fastify.addHook('onRequest', (request: any, reply: any, done: () => void) => {
+      requestTimes.set(request, Date.now());
+
+      const url = request.raw?.url || request.url || '';
+      store.totalRequests++;
+      const method = request.method || 'GET';
+      if (store.methods[method] !== undefined) {
+        store.methods[method]++;
+      } else {
+        store.methods[method] = 1;
+      }
+
+      done();
+    });
+
+    // 2. Hook into onResponse to record metrics
+    fastify.addHook('onResponse', (request: any, reply: any, done: () => void) => {
+      const startTime = requestTimes.get(request) || Date.now();
+      const timeMs = Date.now() - startTime;
+      const durationMs = Number(timeMs.toFixed(2));
+
+      store.totalDuration += timeMs;
+      store.recordLatency(timeMs);
+
+      const status = reply.statusCode || 200;
+      const url = request.raw?.url || request.url || '';
+      const method = request.method || 'GET';
+      const requestId = `fastify_${Date.now()}_${Math.random().toString(36).substring(2, 7)}`;
+      const sanitizedHeaders = redactHeaders(request.headers || {}, customRedactList);
+
+      const requestEntry = {
+        id: requestId,
+        timestamp: new Date().toISOString(),
+        method,
+        url,
+        status,
+        durationMs,
+        headers: sanitizedHeaders,
+        ip: request.ip || request.raw?.socket?.remoteAddress || '127.0.0.1',
+        curl: generateCurl({ method, url, headers: sanitizedHeaders, body: request.body }),
+      };
+
+      store.recordRequest(requestEntry);
+
+      if (status >= 400) {
+        store.totalErrors++;
+        store.recordError({
+          id: requestId,
+          timestamp: new Date().toISOString(),
+          method,
+          url,
+          status,
+          durationMs,
+          headers: sanitizedHeaders,
+        });
+      }
+
+      if (store.statusCodes[status] !== undefined) {
+        store.statusCodes[status]++;
+      } else {
+        store.statusCodes[status] = 1;
+      }
+
+      const routeKey = `${method} ${request.routerPath || url}`;
+      store.recordRoute(routeKey, timeMs);
+
+      if (slowThresholdMs > 0 && timeMs >= slowThresholdMs) {
+        store.recordSlowRequest({
+          ...requestEntry,
+          slowThresholdMs,
+        });
+      }
+
+      store.checkAlerts(options);
+      done();
+    });
+
+    // 3. Register Embedded Web Dashboard endpoint on Fastify
+    fastify.get('/express-lens', async (request: any, reply: any) => {
+      reply.type('text/html').send(getDashboardHTML());
+    });
+
+    fastify.get('/express-lens/metrics-json', async (request: any, reply: any) => {
+      reply.type('application/json').send(store.getMetrics());
+    });
+  };
+}
+
+export default fastifyExpressLens;

src/adapters/hono.ts

@@ -0,0 +1,102 @@
+import store from '../store.ts';
+import { redactHeaders, generateCurl } from '../utils.ts';
+import { getDashboardHTML } from '../dashboard.ts';
+import type { ExpressLensOptions } from '../middleware.ts';
+
+/**
+ * Hono & Edge framework adapter for Express Lens HTTP monitoring and debugging.
+ * Compatible with Hono, Cloudflare Workers, Deno, Bun, and Vercel Edge.
+ */
+export function honoExpressLens(options: ExpressLensOptions = {}) {
+  const slowThresholdMs = options.slowThresholdMs != null ? options.slowThresholdMs : 500;
+  const customRedactList = Array.isArray(options.redactHeaders) ? options.redactHeaders : [];
+
+  return async function middleware(c: any, next: () => Promise<void>) {
+    const url = c.req.url || c.req.path || '/';
+
+    // 1. Intercept /express-lens dashboard endpoints directly inside Hono
+    if (url.includes('/express-lens')) {
+      if (url.includes('/metrics-json')) {
+        return c.json(store.getMetrics());
+      }
+      return c.html(getDashboardHTML());
+    }
+
+    const startTime = globalThis.performance ? globalThis.performance.now() : Date.now();
+
+    store.totalRequests++;
+    const method = c.req.method || 'GET';
+    if (store.methods[method] !== undefined) {
+      store.methods[method]++;
+    } else {
+      store.methods[method] = 1;
+    }
+
+    await next();
+
+    const endTime = globalThis.performance ? globalThis.performance.now() : Date.now();
+    const timeMs = endTime - startTime;
+    const durationMs = Number(timeMs.toFixed(2));
+
+    store.totalDuration += timeMs;
+    store.recordLatency(timeMs);
+
+    const status = c.res.status || 200;
+    const requestId = `hono_${Date.now()}_${Math.random().toString(36).substring(2, 7)}`;
+    const headersObj: Record<string, string> = {};
+    if (c.req.raw && c.req.raw.headers) {
+      c.req.raw.headers.forEach((v: string, k: string) => {
+        headersObj[k] = v;
+      });
+    }
+
+    const sanitizedHeaders = redactHeaders(headersObj, customRedactList);
+
+    const requestEntry = {
+      id: requestId,
+      timestamp: new Date().toISOString(),
+      method,
+      url,
+      status,
+      durationMs,
+      headers: sanitizedHeaders,
+      ip: c.req.header('x-forwarded-for') || '127.0.0.1',
+      curl: generateCurl({ method, url, headers: sanitizedHeaders }),
+    };
+
+    store.recordRequest(requestEntry);
+
+    if (status >= 400) {
+      store.totalErrors++;
+      store.recordError({
+        id: requestId,
+        timestamp: new Date().toISOString(),
+        method,
+        url,
+        status,
+        durationMs,
+        headers: sanitizedHeaders,
+      });
+    }
+
+    if (store.statusCodes[status] !== undefined) {
+      store.statusCodes[status]++;
+    } else {
+      store.statusCodes[status] = 1;
+    }
+
+    const routeKey = `${method} ${c.req.path || url}`;
+    store.recordRoute(routeKey, timeMs);
+
+    if (slowThresholdMs > 0 && timeMs >= slowThresholdMs) {
+      store.recordSlowRequest({
+        ...requestEntry,
+        slowThresholdMs,
+      });
+    }
+
+    store.checkAlerts(options);
+  };
+}
+
+export default honoExpressLens;