Create agent.js

agent.js

@@ -0,0 +1,76 @@
+import { spawn } from "child_process";
+import fs from "fs";
+
+let toolSpec;
+export function listTools() {
+  if (!toolSpec) {
+    toolSpec = JSON.parse(fs.readFileSync("tools.json", "utf-8"));
+  }
+  return toolSpec;
+}
+
+/**
+ * Stream a child process over SSE.
+ * send(eventType, payload) writes to the SSE connection.
+ */
+function streamProcess(cmd, args, options, send) {
+  const child = spawn(cmd, args, { shell: false, ...options });
+
+  child.stdout.on("data", (chunk) => {
+    send("output", { data: chunk.toString() });
+  });
+
+  child.stderr.on("data", (chunk) => {
+    send("error", { data: chunk.toString() });
+  });
+
+  child.on("close", (code) => {
+    send("done", { code });
+  });
+
+  child.on("error", (err) => {
+    send("error", { data: String(err) });
+    send("done", { code: -1 });
+  });
+
+  return child;
+}
+
+/**
+ * Execute a tool call and stream results.
+ * tool: "shell" | "python"
+ * args: { command } | { code }
+ */
+export function executeTool(tool, args, send) {
+  if (tool === "shell") {
+    if (!args?.command || typeof args.command !== "string") {
+      send("error", { data: "Missing 'command' string." });
+      return send("done", { code: 2 });
+    }
+    // Use /bin/bash -lc to enable pipes, redirects, env, etc.
+    return streamProcess("/bin/bash", ["-lc", args.command], {}, send);
+  }
+
+  if (tool === "python") {
+    if (!args?.code || typeof args.code !== "string") {
+      send("error", { data: "Missing 'code' string." });
+      return send("done", { code: 2 });
+    }
+    // Run python inline, escape newlines safely by passing as stdin
+    const child = spawn("python3", ["-"], { stdio: ["pipe", "pipe", "pipe"] });
+    child.stdin.write(args.code);
+    child.stdin.end();
+
+    child.stdout.on("data", (chunk) => send("output", { data: chunk.toString() }));
+    child.stderr.on("data", (chunk) => send("error", { data: chunk.toString() }));
+    child.on("close", (code) => send("done", { code }));
+    child.on("error", (err) => {
+      send("error", { data: String(err) });
+      send("done", { code: -1 });
+    });
+    return child;
+  }
+
+  send("error", { data: `Unknown tool '${tool}'.` });
+  send("done", { code: 2 });
+}