diff --git a/docs/adapters/h3.md b/docs/adapters/h3.md
index aba4fc9..c45563c 100644
--- a/docs/adapters/h3.md
+++ b/docs/adapters/h3.md
@@ -10,6 +10,20 @@ pnpm add h3
 
 The adapter exports its own `withSupabase` that returns H3 middleware instead of a fetch handler. Works with standalone H3 servers and Nuxt server routes (which run on H3 under the hood).
 
+## Typing `event.context.supabaseContext`
+
+The middleware stores the context on `event.context.supabaseContext`. Add this declaration once in your project (e.g. in `types/h3.d.ts`) for typed access:
+
+```ts
+import type { SupabaseContext } from '@supabase/server'
+
+declare module 'h3' {
+  interface H3EventContext {
+    supabaseContext: SupabaseContext
+  }
+}
+```
+
 ## Basic app with auth
 
 ```ts
diff --git a/src/adapters/elysia/index.ts b/src/adapters/elysia/index.ts
index 9b61794..b1f6e13 100644
--- a/src/adapters/elysia/index.ts
+++ b/src/adapters/elysia/index.ts
@@ -4,4 +4,4 @@
  * @packageDocumentation
  */
 
-export { withSupabase } from './plugin.js'
+export { SupabaseError, withSupabase } from './plugin.js'
diff --git a/src/adapters/elysia/plugin.ts b/src/adapters/elysia/plugin.ts
index 4c017af..846b59f 100644
--- a/src/adapters/elysia/plugin.ts
+++ b/src/adapters/elysia/plugin.ts
@@ -1,10 +1,10 @@
-import { Elysia } from 'elysia'
+import { Elysia, type ExtractErrorFromHandle } from 'elysia'
 
 import { createSupabaseContext } from '../../create-supabase-context.js'
 import type { AuthError } from '../../errors.js'
 import type { SupabaseContext, WithSupabaseConfig } from '../../types.js'
 
-class SupabaseError extends Error {
+export class SupabaseError extends Error {
   status: number
   declare cause: AuthError
   constructor(inner: AuthError) {
@@ -56,7 +56,39 @@ class SupabaseError extends Error {
  * app.listen(3000)
  * ```
  */
-export function withSupabase(config?: Omit<WithSupabaseConfig, 'cors'>) {
+// The explicit return type below mirrors Elysia's own generic defaults, which use
+// `{}` literals — switching to `object` or `Record<string, never>` would not satisfy
+// the corresponding generic constraints.
+/* eslint-disable @typescript-eslint/no-empty-object-type */
+export function withSupabase(config?: Omit<WithSupabaseConfig, 'cors'>): Elysia<
+  '',
+  { decorator: {}; store: {}; derive: {}; resolve: {} },
+  { typebox: {}; error: { readonly SupabaseError: SupabaseError } },
+  {
+    schema: {}
+    standaloneSchema: {}
+    macro: {}
+    macroFn: {}
+    parser: {}
+    response: {}
+  },
+  {},
+  {
+    derive: {}
+    resolve: { supabaseContext: SupabaseContext }
+    schema: {}
+    standaloneSchema: {}
+    response: ExtractErrorFromHandle<{ supabaseContext: SupabaseContext }>
+  },
+  {
+    derive: {}
+    resolve: {}
+    schema: {}
+    standaloneSchema: {}
+    response: {}
+  }
+> {
+  /* eslint-enable @typescript-eslint/no-empty-object-type */
   return new Elysia()
     .error({ SupabaseError })
     .resolve(async (ctx): Promise<{ supabaseContext: SupabaseContext }> => {
diff --git a/src/adapters/h3/middleware.test.ts b/src/adapters/h3/middleware.test.ts
index 00eb53c..d5c7e7d 100644
--- a/src/adapters/h3/middleware.test.ts
+++ b/src/adapters/h3/middleware.test.ts
@@ -1,8 +1,16 @@
 import { H3, HTTPError, onError } from 'h3'
 import { describe, expect, it } from 'vitest'
 
+import type { SupabaseContext } from '../../types.js'
+
 import { withSupabase } from './middleware.js'
 
+declare module 'h3' {
+  interface H3EventContext {
+    supabaseContext: SupabaseContext
+  }
+}
+
 describe('h3 supabase middleware', () => {
   const env = {
     url: 'https://test.supabase.co',
diff --git a/src/adapters/h3/middleware.ts b/src/adapters/h3/middleware.ts
index 2aad16e..168a754 100644
--- a/src/adapters/h3/middleware.ts
+++ b/src/adapters/h3/middleware.ts
@@ -47,18 +47,13 @@ export function withSupabase(
   config?: Omit<WithSupabaseConfig, 'cors'>,
 ): Middleware {
   return defineMiddleware(async (event, next) => {
-    if (event.context.supabaseContext) return next()
+    const context = event.context as { supabaseContext?: SupabaseContext }
+    if (context.supabaseContext) return next()
     const { data: ctx, error } = await createSupabaseContext(event.req, config)
     if (error) {
       throw new HTTPError(error.message, { status: error.status, cause: error })
     }
-    event.context.supabaseContext = ctx
+    context.supabaseContext = ctx
     return next()
   })
 }
-
-declare module 'h3' {
-  interface H3EventContext {
-    supabaseContext: SupabaseContext
-  }
-}