arcade-mcp/examples/langchain-ts/langgraph-with-user-auth.ts
Sergio Serrano 8d0d77af10
Add Langchain example for our docs. (#399)
These examples are the same we have for Python in our docs.
2025-05-13 20:30:48 -03:00

148 lines
4.3 KiB
TypeScript

import { pathToFileURL } from "node:url";
import { Arcade } from "@arcadeai/arcadejs";
import { toZod } from "@arcadeai/arcadejs/lib";
import type { AIMessage } from "@langchain/core/messages";
import { tool } from "@langchain/core/tools";
import { MessagesAnnotation, StateGraph } from "@langchain/langgraph";
import { ToolNode } from "@langchain/langgraph/prebuilt";
import { ChatOpenAI } from "@langchain/openai";
// Initialize Arcade with API key from environment
const arcade = new Arcade();
// Replace with your application's user ID (e.g. email address, UUID, etc.)
const USER_ID = "user@example.com";
// Initialize tools from GitHub toolkit
const githubToolkit = await arcade.tools.list({ toolkit: "github", limit: 30 });
const arcadeTools = toZod({
tools: githubToolkit.items,
client: arcade,
userId: USER_ID,
});
// Convert Arcade tools to LangGraph tools
const tools = arcadeTools.map(({ name, description, execute, parameters }) =>
tool(execute, {
name,
description,
schema: parameters,
}),
);
// Initialize the prebuilt tool node
const toolNode = new ToolNode(tools);
// Create a language model instance and bind it with the tools
const model = new ChatOpenAI({
model: "gpt-4o",
apiKey: process.env.OPENAI_API_KEY,
});
const modelWithTools = model.bindTools(tools);
// Function to check if a tool requires authorization
async function requiresAuth(toolName: string): Promise<{
needsAuth: boolean;
id: string;
authUrl: string;
}> {
const authResponse = await arcade.tools.authorize({
tool_name: toolName,
user_id: USER_ID,
});
return {
needsAuth: authResponse.status === "pending",
id: authResponse.id ?? "",
authUrl: authResponse.url ?? "",
};
}
// Function to invoke the model and get a response
async function callAgent(
state: typeof MessagesAnnotation.State,
): Promise<typeof MessagesAnnotation.Update> {
const messages = state.messages;
const response = await modelWithTools.invoke(messages);
return { messages: [response] };
}
// Function to determine the next step in the workflow based on the last message
async function shouldContinue(
state: typeof MessagesAnnotation.State,
): Promise<string> {
const lastMessage = state.messages[state.messages.length - 1] as AIMessage;
if (lastMessage.tool_calls?.length) {
for (const toolCall of lastMessage.tool_calls) {
const { needsAuth } = await requiresAuth(toolCall.name);
if (needsAuth) {
return "authorization";
}
}
return "tools"; // Proceed to tool execution if no authorization is needed
}
return "__end__"; // End the workflow if no tool calls are present
}
// Function to handle authorization for tools that require it
async function authorize(
state: typeof MessagesAnnotation.State,
): Promise<typeof MessagesAnnotation.Update> {
const lastMessage = state.messages[state.messages.length - 1] as AIMessage;
for (const toolCall of lastMessage.tool_calls || []) {
const toolName = toolCall.name;
const { needsAuth, id, authUrl } = await requiresAuth(toolName);
if (needsAuth) {
// Prompt the user to visit the authorization URL
console.log(`Visit the following URL to authorize: ${authUrl}`);
// Wait for the user to complete the authorization
const response = await arcade.auth.waitForCompletion(id);
if (response.status !== "completed") {
throw new Error("Authorization failed");
}
}
}
return { messages: [] };
}
// Build the workflow graph
const workflow = new StateGraph(MessagesAnnotation)
.addNode("agent", callAgent)
.addNode("tools", toolNode)
.addNode("authorization", authorize)
.addEdge("__start__", "agent")
.addConditionalEdges("agent", shouldContinue, [
"authorization",
"tools",
"__end__",
])
.addEdge("authorization", "tools")
.addEdge("tools", "agent");
// Compile the graph
const graph = workflow.compile();
const main = async () => {
// Define the input messages from the user
const inputs = {
messages: [
{
role: "user",
content: "Star arcadeai/arcade-ai on github",
},
],
};
// Run the graph and stream the outputs
const stream = await graph.stream(inputs, { streamMode: "values" });
for await (const chunk of stream) {
// Print the last message in the chunk
console.log(chunk.messages[chunk.messages.length - 1].content);
}
};
if (import.meta.url === pathToFileURL(process.argv[1]).href) {
main().catch(console.error);
}
export { graph };