diff --git a/.github/workflows/examples.yaml b/.github/workflows/examples.yaml
index 337f857ac..c62167986 100644
--- a/.github/workflows/examples.yaml
+++ b/.github/workflows/examples.yaml
@@ -11,6 +11,15 @@ permissions:
   contents: read
 
 jobs:
+  test-sveltekit-compat:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v6
+      with:
+        persist-credentials: false
+    - uses: ./.github/actions/setup-mise
+    - run: mise run --skip-deps test:sveltekit-compat
+
   test-astro-compat:
     runs-on: ubuntu-latest
     steps:
diff --git a/CHANGES.md b/CHANGES.md
index 3f160a9da..73bcd438e 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -8,6 +8,20 @@ Version 2.4.2
 
 To be released.
 
+### @fedify/init
+
+ -  Migrated the initialization template script to SvelteKit version 3, by
+    replacing the `$lib` syntax to `#lib`. [[#1222], [#1224] by Jungmin Yoon\]
+
+[#1222]: https://github.com/fedify-dev/fedify/issues/1222
+[#1224]: https://github.com/fedify-dev/fedify/issues/1224
+
+### @fedify/sveltekit
+
+ -  Fixed the hook types returned by `fedifyHook()` to support both SvelteKit 2
+    and 3, so SvelteKit 3 applications can type-check the integration.
+    [[#1222], [#1224]]
+
 
 Version 2.4.1
 -------------
diff --git a/changes.d/init/init-sv-3-migration.md b/changes.d/init/init-sv-3-migration.md
new file mode 100644
index 000000000..c62366fe4
--- /dev/null
+++ b/changes.d/init/init-sv-3-migration.md
@@ -0,0 +1,5 @@
+ -  Migrated the initialization template script to SvelteKit version 3, by
+    replacing the `$lib` syntax to `#lib`. [[#1222], [#1224] by Jungmin Yoon]
+
+[#1222]: https://github.com/fedify-dev/fedify/issues/1222
+[#1224]: https://github.com/fedify-dev/fedify/pull/1224
diff --git a/changes.d/sveltekit/sveltekit-hook-types.md b/changes.d/sveltekit/sveltekit-hook-types.md
new file mode 100644
index 000000000..22d31dc48
--- /dev/null
+++ b/changes.d/sveltekit/sveltekit-hook-types.md
@@ -0,0 +1,3 @@
+ -  Fixed the hook types returned by `fedifyHook()` to support both SvelteKit 2
+    and 3, so SvelteKit 3 applications can type-check the integration.
+    [[#1222], [#1224]]
diff --git a/mise.toml b/mise.toml
index 49dd9b531..fcfe0c035 100644
--- a/mise.toml
+++ b/mise.toml
@@ -292,6 +292,7 @@ depends = [
   "test:node",
   "test:bun",
   "test:astro-compat",
+  "test:sveltekit-compat",
   "test:temporal-polyfill",
 ]
 
@@ -335,6 +336,11 @@ description = "Test @fedify/astro against supported Astro and runtime versions"
 depends = ["build"]
 run = "deno run -A packages/astro/compat/run.ts"
 
+[tasks."test:sveltekit-compat"]
+description = "Check @fedify/sveltekit consumer types against SvelteKit 2 and 3"
+depends = ["build"]
+run = "deno run -A packages/sveltekit/compat/run.ts"
+
 [tasks."test:monitoring"]
 description = "Validate the monitoring example configuration"
 run = "deno run -A examples/monitoring/validate.ts"
diff --git a/packages/init/src/json/deps.json b/packages/init/src/json/deps.json
index 64ec5aefa..ad9d6693d 100644
--- a/packages/init/src/json/deps.json
+++ b/packages/init/src/json/deps.json
@@ -33,6 +33,7 @@
   "npm:solid-js": "^1.9.14",
   "npm:tsx": "^4.23.1",
   "npm:typescript": "^5.9.3",
+  "npm:typescript@6": "^6.0.0",
   "npm:vinxi": "^0.5.11",
   "npm:x-forwarded-fetch": "^0.2.0"
 }
diff --git a/packages/init/src/templates/sveltekit/hooks.server.ts.tpl b/packages/init/src/templates/sveltekit/hooks.server.ts.tpl
index 47a60734e..af91e975e 100644
--- a/packages/init/src/templates/sveltekit/hooks.server.ts.tpl
+++ b/packages/init/src/templates/sveltekit/hooks.server.ts.tpl
@@ -1,6 +1,6 @@
 import { fedifyHook } from "@fedify/sveltekit";
 import { sequence } from "@sveltejs/kit/hooks";
-import federation from "$lib/federation";
+import federation from "#lib/federation.ts";
 
 export const handle = sequence(
   fedifyHook(federation),
diff --git a/packages/init/src/webframeworks/sveltekit.ts b/packages/init/src/webframeworks/sveltekit.ts
index d69ae64ee..401cd925d 100644
--- a/packages/init/src/webframeworks/sveltekit.ts
+++ b/packages/init/src/webframeworks/sveltekit.ts
@@ -23,7 +23,7 @@ const sveltekitDescription: WebFrameworkDescription = {
     },
     devDependencies: {
       ...defaultDevDependencies,
-      "typescript": deps["npm:typescript"],
+      "typescript": deps["npm:typescript@6"],
       "@types/node": deps["npm:@types/node@25"],
       ...(pmToRt(pm) === "deno"
         ? {}
diff --git a/packages/sveltekit/compat/consumer.ts b/packages/sveltekit/compat/consumer.ts
new file mode 100644
index 000000000..59971be80
--- /dev/null
+++ b/packages/sveltekit/compat/consumer.ts
@@ -0,0 +1,19 @@
+import type { Federation } from "@fedify/fedify/federation";
+import { fedifyHook } from "@fedify/sveltekit";
+import { sequence } from "@sveltejs/kit/hooks";
+
+declare const federation: Federation<{ request: Request }>;
+
+// sequence accepts Handle in both major versions, even though the named type
+// is exported from different modules.  Check the consumer's hook assignment,
+// context callback, and composition without skipping library declarations.
+const hook: ReturnType<typeof sequence> = fedifyHook(
+  federation,
+  (event) => ({ request: event.request }),
+);
+const asyncHook: ReturnType<typeof sequence> = fedifyHook(
+  federation,
+  (event) => Promise.resolve({ request: event.request }),
+);
+const composed: ReturnType<typeof sequence> = sequence(hook, asyncHook);
+void composed;
diff --git a/packages/sveltekit/compat/run.ts b/packages/sveltekit/compat/run.ts
new file mode 100644
index 000000000..18a5e9c17
--- /dev/null
+++ b/packages/sveltekit/compat/run.ts
@@ -0,0 +1,115 @@
+import { dirname, fromFileUrl, join, resolve } from "@std/path";
+
+const compatDir = dirname(fromFileUrl(import.meta.url));
+const repoRoot = resolve(compatDir, "../../..");
+const cases = [
+  { kit: "2.0.0", svelte: "^4.0.0", vite: "^5.0.0", plugin: "^3.0.0" },
+  { kit: "2.36.2", svelte: "^5.0.0", vite: "^7.0.0", plugin: "^6.0.0" },
+  { kit: "3.0.0", svelte: "^5.57.1", vite: "^8.0.12", plugin: "^7.0.0" },
+];
+
+const tempDir = await Deno.makeTempDir({ prefix: "fedify-sveltekit-compat-" });
+try {
+  const tarballs = await packFedifyPackages(tempDir);
+  const consumer = await Deno.readTextFile(join(compatDir, "consumer.ts"));
+  for (const testCase of cases) {
+    console.log(`Checking SvelteKit ${testCase.kit} consumer types...`);
+    const dir = join(tempDir, testCase.kit);
+    await Deno.mkdir(dir);
+    await Deno.writeTextFile(
+      join(dir, "package.json"),
+      JSON.stringify({
+        name: "fedify-sveltekit-type-consumer",
+        private: true,
+        type: "module",
+        dependencies: {
+          "@fedify/sveltekit": tarballs.get("@fedify/sveltekit"),
+          "@fedify/fedify": tarballs.get("@fedify/fedify"),
+          "@sveltejs/kit": testCase.kit,
+          "@sveltejs/vite-plugin-svelte": testCase.plugin,
+          svelte: testCase.svelte,
+          vite: testCase.vite,
+          typescript: "^6.0.0",
+          "@types/node": "^22.0.0",
+        },
+        pnpm: { overrides: Object.fromEntries(tarballs) },
+      }),
+    );
+    await Deno.writeTextFile(
+      join(dir, "tsconfig.json"),
+      JSON.stringify({
+        compilerOptions: {
+          strict: true,
+          noEmit: true,
+          skipLibCheck: false,
+          target: "ESNext",
+          module: "NodeNext",
+          moduleResolution: "NodeNext",
+          types: ["node"],
+        },
+        files: ["consumer.mts", "consumer.cts"],
+      }),
+    );
+    await Deno.writeTextFile(join(dir, "consumer.mts"), consumer);
+    await Deno.writeTextFile(join(dir, "consumer.cts"), consumer);
+    // Install packed artifacts rather than workspace links so declarations
+    // resolve SvelteKit from this consumer, not the workspace's pinned 2.x.
+    await run([
+      "pnpm",
+      "install",
+      "--strict-peer-dependencies",
+      "--ignore-scripts",
+    ], dir);
+    await run(["pnpm", "exec", "tsc", "--project", "tsconfig.json"], dir);
+    console.log(`Passed SvelteKit ${testCase.kit} (ESM and CommonJS).`);
+  }
+} finally {
+  await Deno.remove(tempDir, { recursive: true });
+}
+
+async function packFedifyPackages(dir: string): Promise<Map<string, string>> {
+  const tarballs = new Map<string, string>();
+  for (
+    const name of [
+      "sveltekit",
+      "fedify",
+      "uri-template",
+      "vocab",
+      "vocab-runtime",
+      "vocab-tools",
+      "webfinger",
+    ]
+  ) {
+    const packageDir = join(repoRoot, "packages", name);
+    const outputDir = join(dir, "packages", name);
+    await Deno.mkdir(outputDir, { recursive: true });
+    await run([
+      "pnpm",
+      "pack",
+      "--config.ignore-scripts=true",
+      "--pack-destination",
+      outputDir,
+    ], packageDir);
+    for await (const entry of Deno.readDir(outputDir)) {
+      if (entry.isFile && entry.name.endsWith(".tgz")) {
+        tarballs.set(`@fedify/${name}`, `file:${join(outputDir, entry.name)}`);
+      }
+    }
+    if (!tarballs.has(`@fedify/${name}`)) {
+      throw new Error(`No tarball produced for @fedify/${name}`);
+    }
+  }
+  return tarballs;
+}
+
+async function run(args: string[], cwd: string): Promise<void> {
+  const result = await new Deno.Command(args[0], {
+    args: args.slice(1),
+    cwd,
+    stdout: "inherit",
+    stderr: "inherit",
+  }).output();
+  if (!result.success) {
+    throw new Error(`Command failed (${result.code}): ${args.join(" ")}`);
+  }
+}
diff --git a/packages/sveltekit/src/mod.ts b/packages/sveltekit/src/mod.ts
index b8bc3ad1e..9d5edb0bb 100644
--- a/packages/sveltekit/src/mod.ts
+++ b/packages/sveltekit/src/mod.ts
@@ -14,7 +14,12 @@ import type {
   Federation,
   FederationFetchOptions,
 } from "@fedify/fedify/federation";
-import type { Handle, RequestEvent } from "@sveltejs/kit";
+import type { RequestEvent } from "@sveltejs/kit";
+import type { sequence } from "@sveltejs/kit/hooks";
+
+// Handle moved from @sveltejs/kit to @sveltejs/kit/hooks in SvelteKit 3.
+// sequence has the same public location in both supported major versions.
+type Handle = ReturnType<typeof sequence>;
 
 /**
  * Create a SvelteKit hook handler to integrate with the {@link Federation}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 92f03442a..56ce9381e 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -103,7 +103,7 @@ catalogs:
       specifier: jsr:^1.0.6
       version: 1.1.0
     '@sveltejs/kit':
-      specifier: ^2.0.0
+      specifier: ^2.0.0 || ^3.0.0
       version: 2.36.2
     '@types/amqplib':
       specifier: ^0.10.8
@@ -39912,7 +39912,7 @@ snapshots:
       '@poppinss/colors': 4.1.6
       '@poppinss/dumper': 0.6.5
       '@speed-highlight/core': 1.2.15
-      cookie: 1.0.2
+      cookie: 1.1.1
       youch-core: 0.3.3
 
   youch@4.1.1:
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 2ed6b43cd..a687b346b 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -109,7 +109,7 @@ catalog:
   "@std/assert": "jsr:^1.0.13"
   "@std/async": "jsr:^1.0.13"
   "@std/path": "jsr:^1.0.6"
-  "@sveltejs/kit": ^2.0.0
+  "@sveltejs/kit": ^2.0.0 || ^3.0.0
   "@types/amqplib": ^0.10.8
   "@types/better-sqlite3": ^7.6.13
   "@types/bun": ^1.2.23