Merge branch 'lee/add-workflow-editor' into tp/support-dev-mode-for-backend-ts-server

packages/server/examples/devmode/README.md

@@ -0,0 +1,21 @@
+This example shows how to use the dev mode of the server.
+
+First, we need to set `devMode` to `true` in the `uiConfig` of the server.
+
+```ts
+new LlamaIndexServer({
+  workflow: workflowFactory,
+  uiConfig: {
+    appTitle: "Calculator",
+    devMode: true,
+  },
+  port: 6000,
+}).start();
+```
+
+Export OpenAI API key and start the server in dev mode.
+
+```bash
+export OPENAI_API_KEY=<your-openai-api-key>
+npx tsx watch index.ts
+```

packages/server/examples/devmode/index.ts

@@ -0,0 +1,15 @@
+import { LlamaIndexServer } from "@llamaindex/server";
+import { workflowFactory } from "./src/app/workflow";
+
+new LlamaIndexServer({
+  workflow: workflowFactory,
+  uiConfig: {
+    appTitle: "Calculator",
+    devMode: true,
+    starterQuestions: [
+      "What is the weather in Tokyo?",
+      "What is the weather in New York?",
+    ],
+  },
+  port: 6005,
+}).start();

packages/server/examples/devmode/src/app/workflow.ts

@@ -0,0 +1,16 @@
+import { agent } from "@llamaindex/workflow";
+import { tool } from "llamaindex";
+import { z } from "zod";
+
+export const workflowFactory = async () => {
+  return agent({
+    tools: [
+      tool({
+        name: "weather",
+        description: "Get the weather in a specific city",
+        parameters: z.object({ city: z.string() }),
+        execute: ({ city }) => `The weather in ${city} is sunny`,
+      }),
+    ],
+  });
+};

packages/server/src/handlers/files.ts

@@ -1,7 +1,9 @@
+import { exec } from "child_process";
 import fs from "fs";
 import type { IncomingMessage, ServerResponse } from "http";
+import path from "path";
 import { promisify } from "util";
-import { sendJSONResponse } from "../utils/request";
+import { parseRequestBody, sendJSONResponse } from "../utils/request";
 
 export const handleServeFiles = async (
   req: IncomingMessage,
@@ -21,3 +23,84 @@ export const handleServeFiles = async (
     return sendJSONResponse(res, 404, { error: "File not found" });
   }
 };
+
+const DEFAULT_WORKFLOW_FILE_PATH = "src/app/workflow.ts"; // TODO: we can make it as a parameter in server later
+
+export const getWorkflowFile = async (
+  req: IncomingMessage,
+  res: ServerResponse,
+  filePath: string = DEFAULT_WORKFLOW_FILE_PATH,
+) => {
+  const fileExists = await promisify(fs.exists)(filePath);
+  if (!fileExists) {
+    return sendJSONResponse(res, 404, {
+      detail: `Dev mode is currently in beta. It only supports updating workflow file at ${DEFAULT_WORKFLOW_FILE_PATH}`,
+    });
+  }
+
+  const content = await promisify(fs.readFile)(filePath, "utf-8");
+  const last_modified = fs.statSync(filePath).mtime.getTime();
+  sendJSONResponse(res, 200, { content, file_path: filePath, last_modified });
+};
+
+export const updateWorkflowFile = async (
+  req: IncomingMessage,
+  res: ServerResponse,
+  filePath: string = DEFAULT_WORKFLOW_FILE_PATH,
+) => {
+  const body = await parseRequestBody(req);
+  const { content } = body as { content: string };
+
+  const fileExists = await promisify(fs.exists)(filePath);
+  if (!fileExists) {
+    return sendJSONResponse(res, 404, {
+      detail: `Dev mode is currently in beta. It only supports updating workflow file at ${DEFAULT_WORKFLOW_FILE_PATH}`,
+    });
+  }
+
+  try {
+    const resolvedFilePath = path.resolve(DEFAULT_WORKFLOW_FILE_PATH);
+    const result = await validateTypeScriptFile(resolvedFilePath, content);
+
+    if (!result.isValid) {
+      return sendJSONResponse(res, 400, {
+        detail: result.errors.join("\n"),
+      });
+    }
+
+    await promisify(fs.writeFile)(filePath, content);
+    sendJSONResponse(res, 200, { content });
+  } catch (error) {
+    console.error("Error updating workflow file:", error);
+    sendJSONResponse(res, 500, { error: "Failed to update workflow file" });
+  }
+};
+
+// use typescript package to validate the file syntax and imports
+async function validateTypeScriptFile(filePath: string, content: string) {
+  // Update workflow file directly will cause the server restart immediately.
+  // So we create a temporary file with the same content in the same directory as the workflow file
+  // This file will be used to validate the file syntax and imports. It will be deleted after validation.
+  const tempFilePath = path.join(
+    path.dirname(filePath),
+    `workflow_${Date.now()}.ts`,
+  );
+  fs.writeFileSync(tempFilePath, content);
+
+  const errors = [];
+  try {
+    const tscCommand = `npx tsc ${tempFilePath} --noEmit --skipLibCheck true`;
+    await promisify(exec)(tscCommand);
+  } catch (error) {
+    const errorMessage = (error as { stdout: string })?.stdout;
+    errors.push(errorMessage);
+  } finally {
+    // Clean up temporary file
+    if (fs.existsSync(tempFilePath)) fs.unlinkSync(tempFilePath);
+  }
+
+  return {
+    isValid: errors.length === 0,
+    errors: errors,
+  };
+}

packages/server/src/server.ts

@@ -9,8 +9,13 @@ import { promisify } from "util";
 import { handleChat } from "./handlers/chat";
 import { getLlamaCloudConfig } from "./handlers/cloud";
 import { getComponents } from "./handlers/components";
-import { handleServeFiles } from "./handlers/files";
+import {
+  getWorkflowFile,
+  handleServeFiles,
+  updateWorkflowFile,
+} from "./handlers/files";
 import type { LlamaIndexServerOptions } from "./types";
+
 const nextDir = path.join(__dirname, "..", "server");
 const configFile = path.join(__dirname, "..", "server", "public", "config.js");
 const dev = process.env.NODE_ENV !== "production";
@@ -44,6 +49,7 @@ export class LlamaIndexServer {
         ? "/api/chat/config/llamacloud"
         : undefined;
     const componentsApi = this.componentsDir ? "/api/components" : undefined;
+    const devMode = uiConfig?.devMode ?? false;
 
     // content in javascript format
     const content = `
@@ -52,7 +58,8 @@ export class LlamaIndexServer {
         APP_TITLE: ${JSON.stringify(appTitle)},
         LLAMA_CLOUD_API: ${JSON.stringify(llamaCloudApi)},
         STARTER_QUESTIONS: ${JSON.stringify(starterQuestions)},
-        COMPONENTS_API: ${JSON.stringify(componentsApi)}
+        COMPONENTS_API: ${JSON.stringify(componentsApi)},
+        DEV_MODE: ${JSON.stringify(devMode)}
       }
     `;
     fs.writeFileSync(configFile, content);
@@ -96,6 +103,14 @@ export class LlamaIndexServer {
         return getLlamaCloudConfig(req, res);
       }
 
+      if (pathname === "/api/dev/files/workflow" && req.method === "GET") {
+        return getWorkflowFile(req, res);
+      }
+
+      if (pathname === "/api/dev/files/workflow" && req.method === "PUT") {
+        return updateWorkflowFile(req, res);
+      }
+
       const handle = this.app.getRequestHandler();
       handle(req, res, parsedUrl);
     });

packages/server/src/types.ts

@@ -17,6 +17,7 @@ export type UIConfig = {
   starterQuestions?: string[];
   componentsDir?: string;
   llamaCloudIndexSelector?: boolean;
+  devMode?: boolean;
 };
 
 export type LlamaIndexServerOptions = NextAppOptions & {