Fix AI stream by returning stream.value directly from Server Actions.

createStreamableValue must be created and returned in the action itself; wrapping in { data } or a helper return caused production RSC serialization errors.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/ai/stream.ts

@@ -3,6 +3,8 @@ import { createOpenAI } from "@ai-sdk/openai";
 import { createStreamableValue } from "ai/rsc";
 import { ERROR_PREFIX } from "@/lib/constant";
 
+export type AIStream = ReturnType<typeof createStreamableValue<string>>;
+
 function getOpenAiBaseUrl(): string {
   return (
     process.env.OPENAI_BASE_URL ??
@@ -14,77 +16,74 @@ function getOpenAiBaseUrl(): string {
 const model =
   process.env.OPENAI_MODEL ?? "huihui_ai/gemma-4-abliterated:e4b";
 
-export async function streamAIResponse(
-  system: string,
-  user: string,
-): Promise<{ data?: ReturnType<typeof createStreamableValue<string>>["value"]; error?: string }> {
+export function assertOpenAiKey(): string {
   const apiKey = process.env.OPENAI_API_KEY?.trim();
   if (!apiKey) {
-    return { error: "未配置 OPENAI_API_KEY，请在 .env.local 或 Docker env_file 中设置" };
+    throw new Error(
+      "未配置 OPENAI_API_KEY，请在 .env.local 或 Docker env_file 中设置",
+    );
   }
+  return apiKey;
+}
 
+/** 在 Server Action 内 createStreamableValue 后调用，不可从子函数返回 stream.value */
+export function pumpAIStream(
+  stream: AIStream,
+  system: string,
+  user: string,
+): void {
   const openai = createOpenAI({
-    apiKey,
+    apiKey: assertOpenAiKey(),
     baseURL: getOpenAiBaseUrl(),
   });
 
-  const stream = createStreamableValue<string>();
+  const { fullStream } = streamText({
+    temperature: 0.5,
+    model: openai(model),
+    messages: [
+      { role: "system", content: system },
+      { role: "user", content: user },
+    ],
+    maxRetries: 0,
+  });
 
-  try {
-    const { fullStream } = streamText({
-      temperature: 0.5,
-      model: openai(model),
-      messages: [
-        { role: "system", content: system },
-        { role: "user", content: user },
-      ],
-      maxRetries: 0,
-    });
+  let buffer = "";
+  let done = false;
+  const intervalId = setInterval(() => {
+    if (done && buffer.length === 0) {
+      clearInterval(intervalId);
+      stream.done();
+      return;
+    }
+    if (buffer.length <= 6) {
+      stream.update(buffer);
+      buffer = "";
+    } else {
+      const chunk = buffer.slice(0, 6);
+      buffer = buffer.slice(6);
+      stream.update(chunk);
+    }
+  }, 60);
 
-    let buffer = "";
-    let done = false;
-    const intervalId = setInterval(() => {
-      if (done && buffer.length === 0) {
-        clearInterval(intervalId);
-        stream.done();
-        return;
-      }
-      if (buffer.length <= 6) {
-        stream.update(buffer);
-        buffer = "";
-      } else {
-        const chunk = buffer.slice(0, 6);
-        buffer = buffer.slice(6);
-        stream.update(chunk);
-      }
-    }, 60);
-
-    (async () => {
-      for await (const part of fullStream) {
-        switch (part.type) {
-          case "text-delta":
-            buffer += part.textDelta;
-            break;
-          case "error": {
-            const err = part.error as { message?: string };
-            stream.update(ERROR_PREFIX + (err.message ?? String(part.error)));
-            break;
-          }
+  (async () => {
+    for await (const part of fullStream) {
+      switch (part.type) {
+        case "text-delta":
+          buffer += part.textDelta;
+          break;
+        case "error": {
+          const err = part.error as { message?: string };
+          stream.update(ERROR_PREFIX + (err.message ?? String(part.error)));
+          break;
         }
       }
-    })()
-      .catch((err) => {
-        const message = err instanceof Error ? err.message : String(err);
-        stream.update(ERROR_PREFIX + message);
-      })
-      .finally(() => {
-        done = true;
-      });
-
-    return { data: stream.value };
-  } catch (err) {
-    stream.done();
-    const message = err instanceof Error ? err.message : String(err);
-    return { error: message };
-  }
+    }
+  })()
+    .catch((err) => {
+      const message = err instanceof Error ? err.message : String(err);
+      stream.update(ERROR_PREFIX + message);
+    })
+    .finally(() => {
+      done = true;
+    });
 }