press_b
Simulate pressing the B button on a GameBoy emulator. Configure the duration in frames to control how long the button is held, enabling precise input for gameplay or testing.
Instructions
Press the B button on the GameBoy
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| duration_frames | No | Number of frames to hold the button |
Implementation Reference
- src/tools.ts:28-35 (handler)Async handler function executed when the 'press_b' tool is called. It presses the B button for the specified number of frames via emulatorService and returns the updated screen as ImageContent.
async ({ duration_frames }): Promise<CallToolResult> => { // Press the button using the service (advances one frame) emulatorService.pressButton(button, duration_frames); // Return the current screen using the service const screen = emulatorService.getScreen(); return { content: [screen] }; } - src/tools.ts:25-27 (schema)Zod schema defining the input parameters for the press_b tool: optional duration_frames (defaults to 25).
{ duration_frames: z.number().int().positive().optional().default(1).describe('Number of frames to hold the button').default(25) }, - src/tools.ts:21-36 (registration)Loop that registers the 'press_b' tool (when button==='B') on the MCP server, including name, description, schema, and handler.
Object.values(GameBoyButton).forEach(button => { server.tool( `press_${button.toLowerCase()}`, `Press the ${button} button on the GameBoy`, { duration_frames: z.number().int().positive().optional().default(1).describe('Number of frames to hold the button').default(25) }, async ({ duration_frames }): Promise<CallToolResult> => { // Press the button using the service (advances one frame) emulatorService.pressButton(button, duration_frames); // Return the current screen using the service const screen = emulatorService.getScreen(); return { content: [screen] }; } ); - src/server/server.ts:24-26 (registration)Invokes registration of press_b tool (via registerGameBoyTools) on the MCP server instance.
// Register GameBoy tools registerGameBoyTools(server, emulatorService); // Pass emulatorService - src/emulatorService.ts:72-80 (helper)Supporting method called by the tool handler to press the specified button (B for press_b) and return the screen.
pressButton(button: GameBoyButton, durationFrames: number): ImageContent { log.debug(`Pressing button: ${button}`); if (!this.isRomLoaded()) { log.warn('Attempted to press button with no ROM loaded'); throw new Error('No ROM loaded'); } this.emulator.pressButton(button, durationFrames); // This advances one frame return this.getScreen(); }