feat(runtime): add talk mode and capture tools

src/tools/builtin/capture.ts

@@ -0,0 +1,124 @@
+import { execFile } from 'child_process';
+import { randomUUID } from 'crypto';
+import { readFile, unlink } from 'fs/promises';
+import { join } from 'path';
+import { tmpdir } from 'os';
+
+import type { Tool, ToolResult } from '../types.js';
+
+interface CaptureArgs {
+  format?: 'png' | 'jpg';
+}
+
+interface CameraCaptureArgs extends CaptureArgs {
+  device?: string;
+}
+
+const DEFAULT_TIMEOUT_MS = 15000;
+
+function tempPath(format: string): string {
+  return join(tmpdir(), `flynn-capture-${randomUUID()}.${format}`);
+}
+
+function exec(command: string, args: string[], timeoutMs = DEFAULT_TIMEOUT_MS): Promise<void> {
+  return new Promise((resolve, reject) => {
+    execFile(command, args, { timeout: timeoutMs }, (error, _stdout, stderr) => {
+      if (error) {
+        reject(new Error(`${command} ${args.join(' ')} failed: ${stderr || error.message}`));
+        return;
+      }
+      resolve();
+    });
+  });
+}
+
+async function readBase64AndCleanup(path: string): Promise<string> {
+  try {
+    const data = await readFile(path);
+    return data.toString('base64');
+  } finally {
+    await unlink(path).catch(() => {});
+  }
+}
+
+export const screenCaptureTool: Tool = {
+  name: 'screen.capture',
+  description: 'Capture the current screen and return a base64-encoded image (png/jpg).',
+  inputSchema: {
+    type: 'object',
+    properties: {
+      format: { type: 'string', description: 'Image format: png (default) or jpg' },
+    },
+  },
+  execute: async (rawArgs: unknown): Promise<ToolResult> => {
+    try {
+      const args = (rawArgs as CaptureArgs | undefined) ?? {};
+      const format = args.format === 'jpg' ? 'jpg' : 'png';
+      const out = tempPath(format);
+
+      if (process.platform === 'darwin') {
+        await exec('screencapture', ['-x', '-t', format === 'jpg' ? 'jpg' : 'png', out]);
+      } else if (process.platform === 'linux') {
+        try {
+          await exec('grim', [out]);
+        } catch {
+          await exec('import', ['-window', 'root', out]);
+        }
+      } else {
+        return { success: false, output: '', error: 'screen.capture is only supported on macOS/Linux hosts' };
+      }
+
+      const data = await readBase64AndCleanup(out);
+      return {
+        success: true,
+        output: JSON.stringify({ mimeType: format === 'jpg' ? 'image/jpeg' : 'image/png', data }),
+      };
+    } catch (error) {
+      return {
+        success: false,
+        output: '',
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
+  },
+};
+
+export const cameraCaptureTool: Tool = {
+  name: 'camera.capture',
+  description: 'Capture a single frame from the default camera and return a base64-encoded image.',
+  inputSchema: {
+    type: 'object',
+    properties: {
+      format: { type: 'string', description: 'Image format: png (default) or jpg' },
+      device: { type: 'string', description: 'Optional camera device identifier (platform-specific)' },
+    },
+  },
+  execute: async (rawArgs: unknown): Promise<ToolResult> => {
+    try {
+      const args = (rawArgs as CameraCaptureArgs | undefined) ?? {};
+      const format = args.format === 'jpg' ? 'jpg' : 'png';
+      const out = tempPath(format);
+
+      if (process.platform === 'darwin') {
+        await exec('imagesnap', ['-q', '-w', '1', out]);
+      } else if (process.platform === 'linux') {
+        const device = args.device ?? '/dev/video0';
+        await exec('ffmpeg', ['-y', '-f', 'video4linux2', '-i', device, '-frames:v', '1', out]);
+      } else {
+        return { success: false, output: '', error: 'camera.capture is only supported on macOS/Linux hosts' };
+      }
+
+      const data = await readBase64AndCleanup(out);
+      return {
+        success: true,
+        output: JSON.stringify({ mimeType: format === 'jpg' ? 'image/jpeg' : 'image/png', data }),
+      };
+    } catch (error) {
+      return {
+        success: false,
+        output: '',
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
+  },
+};