feat: disable development logging by setting logging: false in next config

docs/02-app/02-api-reference/05-next-config-js/logging.mdx

@@ -18,3 +18,11 @@ module.exports = {
   },
 }
 ```
+
+In addition, you can disable the development logging by setting `logging` to `false`.
+
+```js filename="next.config.js"
+module.exports = {
+  logging: false,
+}
+```

packages/next/src/build/output/store.ts

@@ -7,8 +7,18 @@ import * as Log from './log'
 const MAX_LOG_SKIP_DURATION = 500 // 500ms
 
 export type OutputState =
-  | { bootstrap: true; appUrl: string | null; bindAddr: string | null }
-  | ({ bootstrap: false; appUrl: string | null; bindAddr: string | null } & (
+  | {
+      bootstrap: true
+      appUrl: string | null
+      bindAddr: string | null
+      logging: boolean
+    }
+  | ({
+      bootstrap: false
+      appUrl: string | null
+      bindAddr: string | null
+      logging: boolean
+    } & (
       | {
           loading: true
           trigger: string | undefined
@@ -41,9 +51,15 @@ export const store = createStore<OutputState>({
   appUrl: null,
   bindAddr: null,
   bootstrap: true,
+  logging: true,
 })
 
-let lastStore: OutputState = { appUrl: null, bindAddr: null, bootstrap: true }
+let lastStore: OutputState = {
+  appUrl: null,
+  bindAddr: null,
+  bootstrap: true,
+  logging: true,
+}
 function hasStoreChanged(nextStore: OutputState) {
   if (
     (
@@ -66,6 +82,10 @@ let loadingLogTimer: NodeJS.Timeout | null = null
 let traceSpan: Span | null = null
 
 store.subscribe((state) => {
+  if (state.logging === false) {
+    return
+  }
+
   if (!hasStoreChanged(state)) {
     return
   }

packages/next/src/server/config-schema.ts

@@ -533,13 +533,16 @@ export const configSchema: zod.ZodType<NextConfig> = z.lazy(() =>
       })
       .optional(),
     logging: z
-      .object({
-        fetches: z
-          .object({
-            fullUrl: z.boolean().optional(),
-          })
-          .optional(),
-      })
+      .union([
+        z.object({
+          fetches: z
+            .object({
+              fullUrl: z.boolean().optional(),
+            })
+            .optional(),
+        }),
+        z.boolean(),
+      ])
       .optional(),
     modularizeImports: z
       .record(

packages/next/src/server/config-shared.ts

@@ -852,11 +852,13 @@ export interface NextConfig extends Record<string, any> {
     }
   >
 
-  logging?: {
-    fetches?: {
-      fullUrl?: boolean
-    }
-  }
+  logging?:
+    | {
+        fetches?: {
+          fullUrl?: boolean
+        }
+      }
+    | boolean
 
   /**
    * period (in seconds) where the server allow to serve stale cache

packages/next/src/server/dev/hot-reloader-turbopack.ts

@@ -256,6 +256,7 @@ export async function createHotReloaderTurbopack(
           loading: true,
           trigger: id,
           url: requestUrl,
+          logging: nextConfig.logging,
         } as OutputState,
         true
       )
@@ -272,6 +273,7 @@ export async function createHotReloaderTurbopack(
         consoleStore.setState(
           {
             loading: false,
+            logging: nextConfig.logging,
           } as OutputState,
           true
         )

packages/next/src/server/next-server.ts

@@ -1118,7 +1118,22 @@ export default class NextNodeServer extends BaseServer<
       const normalizedReq = this.normalizeReq(req)
       const normalizedRes = this.normalizeRes(res)
 
-      const loggingFetchesConfig = this.nextConfig.logging?.fetches
+      let logging = this.nextConfig.logging
+      let isLoggingDisabled = false
+      if (typeof logging === 'boolean') {
+        if (logging === false) {
+          // disable all logging options if logging === false
+          logging = {}
+          isLoggingDisabled = true
+        }
+        // explicit check value for better readability
+        if (logging === true) {
+          // enable all logging options if logging === true
+          logging = { fetches: { fullUrl: true } }
+        }
+      }
+
+      const loggingFetchesConfig = logging?.fetches
       const enabledVerboseLogging = !!loggingFetchesConfig
       const shouldTruncateUrl = !loggingFetchesConfig?.fullUrl
 
@@ -1132,6 +1147,11 @@ export default class NextNodeServer extends BaseServer<
         const isMiddlewareRequest = getRequestMeta(req, 'middlewareInvoke')
 
         const reqCallback = () => {
+          const fetchMetrics = normalizedReq.fetchMetrics || []
+          delete normalizedReq.fetchMetrics
+
+          if (isLoggingDisabled) return
+
           // we don't log for non-route requests
           const routeMatch = getRequestMeta(req).match
 
@@ -1142,7 +1162,6 @@ export default class NextNodeServer extends BaseServer<
           const isRSC = getRequestMeta(normalizedReq, 'isRSCRequest')
 
           const reqEnd = Date.now()
-          const fetchMetrics = normalizedReq.fetchMetrics || []
           const reqDuration = reqEnd - reqStart
 
           const statusColor = (status?: number) => {
@@ -1252,7 +1271,6 @@ export default class NextNodeServer extends BaseServer<
               }
             }
           }
-          delete normalizedReq.fetchMetrics
           originalResponse.off('close', reqCallback)
         }
         originalResponse.on('close', reqCallback)

test/development/app-dir/disable-logging-route/app/[id]/page.tsx

@@ -0,0 +1,3 @@
+export default function Page({ params: { id } }) {
+  return <p>{id}</p>
+}

test/development/app-dir/disable-logging-route/app/layout.tsx

@@ -0,0 +1,8 @@
+import { ReactNode } from 'react'
+export default function Root({ children }: { children: ReactNode }) {
+  return (
+    <html>
+      <body>{children}</body>
+    </html>
+  )
+}

test/development/app-dir/disable-logging-route/disable-logging-route.test.ts

@@ -0,0 +1,27 @@
+import { nextTestSetup } from 'e2e-utils'
+import { check } from 'next-test-utils'
+
+describe('disable-logging-route', () => {
+  const { next } = nextTestSetup({
+    files: __dirname,
+  })
+
+  it('should not log if disabled logging', async () => {
+    const html = await next.render('/slug1')
+    expect(html).toContain('slug1')
+    expect(next.cliOutput).not.toContain('GET /slug1')
+
+    // re-enable logging
+    await next.patchFile('next.config.js', (content) =>
+      content.replace('logging: false,', '')
+    )
+
+    // should log now
+    await check(async () => {
+      const html = await next.render('/slug1')
+      expect(html).toContain('slug1')
+      expect(next.cliOutput).toContain('GET /slug1')
+      return 'success'
+    }, 'success')
+  })
+})

test/development/app-dir/disable-logging-route/next.config.js

@@ -0,0 +1,8 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+const nextConfig = {
+  logging: false,
+}
+
+module.exports = nextConfig