From 1c64bda3f2d3d0d0815594de9118386f125a0403 Mon Sep 17 00:00:00 2001
From: Birk Skyum <birk.skyum@pm.me>
Date: Thu, 16 Jul 2026 05:57:59 +0200
Subject: [PATCH 1/2] fix: use per-environment Vite plugin hook APIs

---
 .changeset/tame-dingos-wave.md         | 5 +++++
 packages/start/src/config/env.ts       | 9 +++++----
 packages/start/src/directives/index.ts | 8 ++++----
 3 files changed, 14 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/tame-dingos-wave.md

diff --git a/.changeset/tame-dingos-wave.md b/.changeset/tame-dingos-wave.md
new file mode 100644
index 000000000..9f98046db
--- /dev/null
+++ b/.changeset/tame-dingos-wave.md
@@ -0,0 +1,5 @@
+---
+"@solidjs/start": patch
+---
+
+Use per-environment Vite plugin hook APIs for forward compatibility with Vite 9.
diff --git a/packages/start/src/config/env.ts b/packages/start/src/config/env.ts
index fb98c200e..a8683e98e 100644
--- a/packages/start/src/config/env.ts
+++ b/packages/start/src/config/env.ts
@@ -71,9 +71,10 @@ export function envPlugin(options?: EnvPluginOptions): Plugin {
       }
       return undefined;
     },
-    load(id, opts) {
+    load(id) {
+      const isServer = this.environment.config.consumer === "server";
       if (id === SERVER_ENV) {
-        if (!opts?.ssr) {
+        if (!isServer) {
           return SERVER_ONLY_MODULE;
         }
         const vars = currentOptions.server?.load
@@ -88,13 +89,13 @@ export function envPlugin(options?: EnvPluginOptions): Plugin {
         return convertObjectToModule(vars);
       }
       if (id === SERVER_RUNTIME_LOADER) {
-        if (!opts?.ssr) {
+        if (!isServer) {
           return SERVER_ONLY_MODULE;
         }
         return runtimeCode;
       }
       if (id === SERVER_RUNTIME_ENV) {
-        if (!opts?.ssr) {
+        if (!isServer) {
           return SERVER_ONLY_MODULE;
         }
         return SERVER_RUNTIME_CODE;
diff --git a/packages/start/src/directives/index.ts b/packages/start/src/directives/index.ts
index 04a30395c..0a012aad4 100644
--- a/packages/start/src/directives/index.ts
+++ b/packages/start/src/directives/index.ts
@@ -181,8 +181,8 @@ export function serverFunctionsPlugin(options: ServerFunctionsOptions): Plugin[]
         }
         return null;
       },
-      async load(id, opts) {
-        const mode = opts?.ssr ? "server" : "client";
+      async load(id) {
+        const mode = this.environment.config.consumer;
         if (id === options.manifest) {
           const current = new Debouncer(() =>
             [...manifest[mode]].map(entry => `import "${entry}";`).join("\n"),
@@ -197,8 +197,8 @@ export function serverFunctionsPlugin(options: ServerFunctionsOptions): Plugin[]
     {
       name: "solid-start:server-functions/compiler",
       enforce: 'pre',
-      async transform(code, fileId, opts) {
-        const mode = opts?.ssr ? "server" : "client";
+      async transform(code, fileId) {
+        const mode = this.environment.config.consumer;
         const [id] = fileId.split("?");
         if (!filter(id)) {
           return null;

From 1d174b77f42d49dc7d957d4bfb15cfd96dd6c57e Mon Sep 17 00:00:00 2001
From: Birk Skyum <birk.skyum@pm.me>
Date: Thu, 16 Jul 2026 05:59:29 +0200
Subject: [PATCH 2/2] or vite 9

---
 packages/start/package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/start/package.json b/packages/start/package.json
index babc047d1..edfb886bc 100644
--- a/packages/start/package.json
+++ b/packages/start/package.json
@@ -89,6 +89,6 @@
     "vitest": "^4.1.0"
   },
   "peerDependencies": {
-    "vite": "^8"
+    "vite": "^8 || ^9"
   }
 }