1 files changed, 33 insertions, 0 deletions
diff --git a/packages/core/src/tools/write-file.ts b/packages/core/src/tools/write-file.ts
new file mode 100644
index 0000000..23bc72a
--- /dev/null
+++ b/packages/core/src/tools/write-file.ts
@@ -0,0 +1,33 @@
+import { mkdir, writeFile } from "node:fs/promises";
+import { dirname, join, resolve } from "node:path";
+import { z } from "zod";
+import type { ToolDefinition } from "../types/index.js";
+
+export function createWriteFileTool(workingDirectory: string): ToolDefinition {
+	return {
+		name: "write_file",
+		description: "Write content to a file relative to the working directory.",
+		parameters: z.object({
+			path: z.string().describe("Path to the file, relative to the working directory"),
+			content: z.string().describe("Content to write to the file"),
+		}),
+		execute: async (args: Record<string, unknown>): Promise<string> => {
+			const filePath = args.path as string;
+			const content = args.content as string;
+			const absolutePath = resolve(join(workingDirectory, filePath));
+			const absoluteWorkDir = resolve(workingDirectory);
+
+			if (!absolutePath.startsWith(`${absoluteWorkDir}/`) && absolutePath !== absoluteWorkDir) {
+				return `Error: Path "${filePath}" is outside the working directory.`;
+			}
+
+			try {
+				await mkdir(dirname(absolutePath), { recursive: true });
+				await writeFile(absolutePath, content, "utf8");
+				return `Successfully wrote to "${filePath}".`;
+			} catch (err) {
+				return `Error writing file: ${err instanceof Error ? err.message : String(err)}`;
+			}
+		},
+	};
+}