hook main loop from mcp-client/cli.ts

Author: julien-c

packages/tiny-agents/src/cli.ts

@@ -7,7 +7,8 @@ import { PROVIDERS_OR_POLICIES } from "@huggingface/inference";
 import { Agent } from "@huggingface/mcp-client";
 import { version as packageVersion } from "../package.json";
 import { ServerConfigSchema } from "./lib/types";
-import { ANSI, debug, error } from "./lib/utils";
+import { debug, error } from "./lib/utils";
+import { mainCliLoop } from "./lib/mainCliLoop";
 
 const USAGE_HELP = `
 Usage:
@@ -122,9 +123,9 @@ async function main() {
 		error(`Serve is not implemented yet, coming soon!`);
 		process.exit(1);
 	} else {
-		console.debug(agent);
-
-		// TODO: hook main loop from mcp-client/cli.ts
+		debug(agent);
+		// main loop from mcp-client/cli.ts
+		await mainCliLoop(agent);
 	}
 }
 

packages/tiny-agents/src/lib/mainCliLoop.ts

@@ -0,0 +1,85 @@
+import * as readline from "node:readline/promises";
+import { stdin, stdout } from "node:process";
+import type { Agent } from "@huggingface/mcp-client";
+import { ANSI } from "./utils";
+
+/**
+ * From mcp-client/cli.ts
+ */
+export async function mainCliLoop(agent: Agent): Promise<void> {
+	const rl = readline.createInterface({ input: stdin, output: stdout });
+	let abortController = new AbortController();
+	let waitingForInput = false;
+	async function waitForInput() {
+		waitingForInput = true;
+		const input = await rl.question("> ");
+		waitingForInput = false;
+		return input;
+	}
+	rl.on("SIGINT", async () => {
+		if (waitingForInput) {
+			// close the whole process
+			await agent.cleanup();
+			stdout.write("\n");
+			rl.close();
+		} else {
+			// otherwise, it means a request is underway
+			abortController.abort();
+			abortController = new AbortController();
+			stdout.write("\n");
+			stdout.write(ANSI.GRAY);
+			stdout.write("Ctrl+C a second time to exit");
+			stdout.write(ANSI.RESET);
+			stdout.write("\n");
+		}
+	});
+	process.on("uncaughtException", (err) => {
+		stdout.write("\n");
+		rl.close();
+		throw err;
+	});
+
+	await agent.loadTools();
+
+	stdout.write(ANSI.BLUE);
+	stdout.write(`Agent loaded with ${agent.availableTools.length} tools:\n`);
+	stdout.write(agent.availableTools.map((t) => `- ${t.function.name}`).join("\n"));
+	stdout.write(ANSI.RESET);
+	stdout.write("\n");
+
+	while (true) {
+		const input = await waitForInput();
+		for await (const chunk of agent.run(input, { abortSignal: abortController.signal })) {
+			if ("choices" in chunk) {
+				const delta = chunk.choices[0]?.delta;
+				if (delta.content) {
+					stdout.write(delta.content);
+				}
+				if (delta.tool_calls) {
+					stdout.write(ANSI.GRAY);
+					for (const deltaToolCall of delta.tool_calls) {
+						if (deltaToolCall.id) {
+							stdout.write(`<Tool ${deltaToolCall.id}>\n`);
+						}
+						if (deltaToolCall.function.name) {
+							stdout.write(deltaToolCall.function.name + " ");
+						}
+						if (deltaToolCall.function.arguments) {
+							stdout.write(deltaToolCall.function.arguments);
+						}
+					}
+					stdout.write(ANSI.RESET);
+				}
+			} else {
+				/// Tool call info
+				stdout.write("\n\n");
+				stdout.write(ANSI.GREEN);
+				stdout.write(`Tool[${chunk.name}] ${chunk.tool_call_id}\n`);
+				stdout.write(chunk.content);
+				stdout.write(ANSI.RESET);
+				stdout.write("\n\n");
+			}
+		}
+		stdout.write("\n");
+	}
+}