diff --git a/vike/client/client-routing-runtime/createPageContext.ts b/vike/client/client-routing-runtime/createPageContext.ts
index 47e34254625..e21ad034329 100644
--- a/vike/client/client-routing-runtime/createPageContext.ts
+++ b/vike/client/client-routing-runtime/createPageContext.ts
@@ -4,8 +4,9 @@ import { getPageContextUrlComputed } from '../../shared/getPageContextUrlCompute
 import { getPageFilesAll } from '../../shared/getPageFiles.js'
 import { loadPageRoutes } from '../../shared/route/loadPageRoutes.js'
 import { getBaseServer } from './getBaseServer.js'
-import { assert, isBaseServer, PromiseType, getGlobalObject, objectAssign } from './utils.js'
+import { assert, isBaseServer, PromiseType, getGlobalObject, objectAssign, isObject } from './utils.js'
 const globalObject = getGlobalObject<{
+  onBootResult?: Record<string, unknown>,
   pageFilesData?: PromiseType<ReturnType<typeof getPageFilesAll>>
 }>('createPageContext.ts', {})
 
@@ -14,7 +15,7 @@ async function createPageContext(urlOriginal: string) {
     globalObject.pageFilesData = await getPageFilesAll(true)
   }
   const { pageFilesAll, allPageIds, pageConfigs, pageConfigGlobal } = globalObject.pageFilesData
-  const { pageRoutes, onBeforeRouteHook } = await loadPageRoutes(
+  const { pageRoutes, onBeforeRouteHook, onBootHook } = await loadPageRoutes(
     pageFilesAll,
     pageConfigs,
     pageConfigGlobal,
@@ -22,7 +23,8 @@ async function createPageContext(urlOriginal: string) {
   )
   const baseServer = getBaseServer()
   assert(isBaseServer(baseServer))
-  const pageContext = {
+
+  let pageContext = {
     urlOriginal,
     _objectCreatedByVike: true,
     _urlHandler: null,
@@ -35,6 +37,18 @@ async function createPageContext(urlOriginal: string) {
     _pageRoutes: pageRoutes,
     _onBeforeRouteHook: onBeforeRouteHook
   }
+
+  if (!globalObject.onBootResult && onBootHook) {
+    globalObject.onBootResult = await onBootHook.hookFn(pageContext) as Record<string, unknown>
+  }
+
+  if (isObject(globalObject.onBootResult)) {
+    pageContext = {
+      ...pageContext,
+      ...globalObject.onBootResult
+    }
+  }
+
   const pageContextUrlComputed = getPageContextUrlComputed(pageContext)
   objectAssign(pageContext, pageContextUrlComputed)
   return pageContext
diff --git a/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig.ts b/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig.ts
index 66f575052a4..baf95830172 100644
--- a/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig.ts
+++ b/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig.ts
@@ -564,7 +564,7 @@ async function getGlobalConfigs(
       )
       const configValueSource = sources[0]
       if (!configValueSource) return
-      if (configName === 'onBeforeRoute' || configName === 'onPrerenderStart') {
+      if (['onBeforeRoute', 'onPrerenderStart', 'onBoot'].includes(configName)) {
         assert(!('value' in configValueSource))
         pageConfigGlobal.configValueSources[configName] = [configValueSource]
       } else {
diff --git a/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig/configDefinitionsBuiltIn.ts b/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig/configDefinitionsBuiltIn.ts
index 832837a1d21..f06b9b99438 100644
--- a/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig/configDefinitionsBuiltIn.ts
+++ b/vike/node/plugin/plugins/importUserCode/v1-design/getVikeConfig/configDefinitionsBuiltIn.ts
@@ -189,6 +189,7 @@ const configDefinitionsBuiltIn: ConfigDefinitionsBuiltIn = {
 }
 
 type ConfigNameGlobal =
+  | 'onBoot'
   | 'onPrerenderStart'
   | 'onBeforeRoute'
   | 'prerender'
@@ -206,6 +207,9 @@ const configDefinitionsBuiltInGlobal: Record<ConfigNameGlobal, ConfigDefinitionI
   onBeforeRoute: {
     env: { server: true, client: 'if-client-routing', eager: true }
   },
+  onBoot: {
+    env: { server: true, client: true, eager: true }
+  },
   prerender: {
     env: { config: true }
   },
diff --git a/vike/node/runtime/renderPage.ts b/vike/node/runtime/renderPage.ts
index 3e57d48dc93..9e9fb98cb2e 100644
--- a/vike/node/runtime/renderPage.ts
+++ b/vike/node/runtime/renderPage.ts
@@ -149,6 +149,14 @@ async function renderPageAndPrepare(
     // From now on, renderContext.pageConfigs contains all the configuration data; getVikeConfig() isn't called anymore for this request
   }
 
+  if (renderContext.onBootHook) {
+    const onBootResult = await renderContext.onBootHook?.hookFn(pageContextInit) as Record<string, unknown>
+    pageContextInit = {
+      ...pageContextInit,
+      ...onBootResult
+    };
+  }
+
   // Check Base URL
   {
     const pageContextHttpResponse = checkBaseUrl(pageContextInit, httpRequestId)
diff --git a/vike/node/runtime/renderPage/renderPageAlreadyRouted.ts b/vike/node/runtime/renderPage/renderPageAlreadyRouted.ts
index 01422895e6e..8365b72b067 100644
--- a/vike/node/runtime/renderPage/renderPageAlreadyRouted.ts
+++ b/vike/node/runtime/renderPage/renderPageAlreadyRouted.ts
@@ -252,6 +252,7 @@ type RenderContext = {
   allPageIds: string[]
   pageRoutes: PageRoutes
   onBeforeRouteHook: Hook | null
+  onBootHook: Hook | null
 }
 // TODO: remove getRenderContext() in favor of getGlobalObject() + reloadGlobalContext()
 // TODO: impl GlobalNodeContext + GlobalClientContext + GloablContext, and use GlobalContext instead of RenderContext
@@ -261,7 +262,7 @@ async function getRenderContext(): Promise<RenderContext> {
     false,
     globalContext.isProduction
   )
-  const { pageRoutes, onBeforeRouteHook } = await loadPageRoutes(
+  const { pageRoutes, onBeforeRouteHook, onBootHook } = await loadPageRoutes(
     pageFilesAll,
     pageConfigs,
     pageConfigGlobal,
@@ -278,7 +279,8 @@ async function getRenderContext(): Promise<RenderContext> {
     pageConfigGlobal,
     allPageIds: allPageIds,
     pageRoutes,
-    onBeforeRouteHook
+    onBeforeRouteHook,
+    onBootHook
   }
   return renderContext
 }
diff --git a/vike/shared/page-configs/Config.ts b/vike/shared/page-configs/Config.ts
index 5ecf84a41fe..b994547fb02 100644
--- a/vike/shared/page-configs/Config.ts
+++ b/vike/shared/page-configs/Config.ts
@@ -15,6 +15,8 @@ export type { OnBeforePrerenderStartAsync }
 export type { OnBeforePrerenderStartSync }
 export type { OnBeforeRenderAsync }
 export type { OnBeforeRenderSync }
+export type { OnBoot }
+export type { OnBootSync }
 export type { OnBeforeRouteAsync }
 export type { OnBeforeRouteSync }
 export type { OnHydrationEndAsync }
@@ -51,12 +53,12 @@ type HookNamePage =
   | 'onRenderClient'
   | 'guard'
   | 'data'
-type HookNameGlobal = 'onBeforePrerender' | 'onBeforeRoute' | 'onPrerenderStart'
+type HookNameGlobal = 'onBeforePrerender' | 'onBeforeRoute' | 'onPrerenderStart' | 'onBoot'
 // v0.4 design TODO/v1-release: remove
 type HookNameOldDesign = 'render' | 'prerender'
 
 type ConfigNameBuiltIn =
-  | Exclude<keyof Config, keyof ConfigVikeUserProvided | 'onBeforeRoute' | 'onPrerenderStart'>
+  | Exclude<keyof Config, keyof ConfigVikeUserProvided | 'onBeforeRoute' | 'onPrerenderStart' | 'onBoot'>
   | 'prerender'
   | 'clientEntryLoaded'
   | 'onBeforeRenderEnv'
@@ -131,6 +133,18 @@ type OnBeforeRenderAsync = (
  *  https://vike.dev/onBeforeRender
  */
 type OnBeforeRenderSync = (pageContext: PageContextServer) => { pageContext: Partial<Vike.PageContext> } | void
+/** Hook called when Vike is first initialized.
+ *
+ *  https://vike.dev/onBoot
+ */
+type OnBoot = (
+  pageContext: PageContextServer
+) => Promise<{ pageContext: Partial<Vike.PageContext> } | void>
+/** Hook called when Vike is first initialized.
+ *
+ *  https://vike.dev/onBoot
+ */
+type OnBootSync = (pageContext: PageContextServer) => { pageContext: Partial<Vike.PageContext> } | void
 /** Hook called before the URL is routed to a page.
  *
  * https://vike.dev/onBeforeRoute
@@ -349,6 +363,12 @@ type ConfigBuiltIn = {
    */
   onBeforePrerenderStart?: OnBeforePrerenderStartAsync | OnBeforePrerenderStartSync | ImportString
 
+  /** Hook called when Vike is first initialized.
+   *
+   * https://vike.dev/onBoot
+   */
+  onBoot?: OnBoot | OnBootSync | ImportString
+
   /** Hook called before the URL is routed to a page.
    *
    * https://vike.dev/onBeforeRoute
diff --git a/vike/shared/route/loadPageRoutes.ts b/vike/shared/route/loadPageRoutes.ts
index 693c46093fb..77eb91c096a 100644
--- a/vike/shared/route/loadPageRoutes.ts
+++ b/vike/shared/route/loadPageRoutes.ts
@@ -30,11 +30,11 @@ async function loadPageRoutes(
   pageConfigs: PageConfigRuntime[],
   pageConfigGlobal: PageConfigGlobalRuntime,
   allPageIds: string[]
-): Promise<{ pageRoutes: PageRoutes; onBeforeRouteHook: null | Hook }> {
+): Promise<{ pageRoutes: PageRoutes; onBeforeRouteHook: null | Hook; onBootHook: null | Hook }> {
   await Promise.all(pageFilesAll.filter((p) => p.fileType === '.page.route').map((p) => p.loadFile?.()))
-  const { onBeforeRouteHook, filesystemRoots } = getGlobalHooks(pageFilesAll, pageConfigs, pageConfigGlobal)
+  const { onBootHook, onBeforeRouteHook, filesystemRoots } = getGlobalHooks(pageFilesAll, pageConfigs, pageConfigGlobal)
   const pageRoutes = getPageRoutes(filesystemRoots, pageFilesAll, pageConfigs, allPageIds)
-  return { pageRoutes, onBeforeRouteHook }
+  return { pageRoutes, onBeforeRouteHook, onBootHook }
 }
 
 function getPageRoutes(
@@ -175,12 +175,14 @@ function getGlobalHooks(
   pageConfigGlobal: PageConfigGlobalRuntime
 ): {
   onBeforeRouteHook: null | Hook
+  onBootHook: null | Hook
   filesystemRoots: null | FilesystemRoot[]
 } {
   // V1 Design
   if (pageConfigs.length > 0) {
-    const hook = getHookFromPageConfigGlobal(pageConfigGlobal, 'onBeforeRoute')
-    return { onBeforeRouteHook: hook, filesystemRoots: null }
+    const onBootHook = getHookFromPageConfigGlobal(pageConfigGlobal, 'onBoot')
+    const onBeforeRouteHook = getHookFromPageConfigGlobal(pageConfigGlobal, 'onBeforeRoute')
+    return { onBootHook, onBeforeRouteHook, filesystemRoots: null }
   }
 
   // Old design
@@ -221,7 +223,7 @@ function getGlobalHooks(
       }
     })
 
-  return { onBeforeRouteHook, filesystemRoots }
+  return { onBootHook: null, onBeforeRouteHook, filesystemRoots }
 }
 
 function dirname(filePath: string): string {