Press Key

Instructions

Implementation Reference

• src/tools/interaction.ts:112-121 (handler)

  The handler function for the 'pinchtab_press' tool. It receives { key, ref }, builds a body with kind:'press', and calls pinch('POST', '/action', body). On error it returns a toolError.

    async ({ key, ref }) => {
      try {
        const body: Record<string, unknown> = { key, kind: "press" };
        if (ref) body.ref = ref;
        return toolResult(await pinch("POST", "/action", body));
      } catch (error) {
        return toolError(error);
      }
    },
  );

• src/tools/interaction.ts:100-111 (schema)

  The tool metadata and input schema for 'pinchtab_press'. Defines 'key' (string, required) and 'ref' (string, optional) inputs. Also sets the description and title.

  {
    description:
      "Press a keyboard key (e.g. 'Enter', 'Tab', 'Escape', 'ArrowDown'). Optionally target a specific element.",
    inputSchema: z.object({
      key: z.string().describe("Key to press (e.g. 'Enter', 'Tab', 'Escape')"),
      ref: z
        .string()
        .optional()
        .describe("Element ref to focus before pressing the key (e.g. 'e5')."),
    }),
    title: "Press Key",
  },

• src/tools/interaction.ts:98-121 (registration)

  Registration of the 'pinchtab_press' tool via server.registerTool(...) inside the registerInteractionTools function.

  server.registerTool(
    "pinchtab_press",
    {
      description:
        "Press a keyboard key (e.g. 'Enter', 'Tab', 'Escape', 'ArrowDown'). Optionally target a specific element.",
      inputSchema: z.object({
        key: z.string().describe("Key to press (e.g. 'Enter', 'Tab', 'Escape')"),
        ref: z
          .string()
          .optional()
          .describe("Element ref to focus before pressing the key (e.g. 'e5')."),
      }),
      title: "Press Key",
    },
    async ({ key, ref }) => {
      try {
        const body: Record<string, unknown> = { key, kind: "press" };
        if (ref) body.ref = ref;
        return toolResult(await pinch("POST", "/action", body));
      } catch (error) {
        return toolError(error);
      }
    },
  );

• src/utils.ts:17-49 (helper)

  The toolResult helper wraps data into an MCP content response. Used by the handler to return success results.

  /** Wrap a tool handler with standardized error handling. */
  export function toolResult(data: unknown): ToolResult {
    return { content: [{ text: toJson(data), type: "text" as const }] };
  }
  
  /** Format an error as an MCP tool error response. */
  export function toolError(error: unknown): ToolResult {
    const message = error instanceof Error ? error.message : String(error);
    return {
      content: [{ text: message, type: "text" as const }],
      isError: true,
    };
  }

• src/pinchtab/client.ts:6-49 (helper)

  The pinch() helper sends HTTP requests to the PinchTab backend. The handler calls pinch('POST', '/action', body) to execute the key press action.

  export async function pinch(
    method: string,
    path: string,
    body?: Record<string, unknown>,
  ): Promise<unknown> {
    if (!(await isPinchtabRunning())) {
      await ensurePinchtabRunning();
    }
  
    const headers: Record<string, string> = {
      "Content-Type": "application/json",
    };
    if (PINCHTAB_TOKEN) {
      headers["Authorization"] = `Bearer ${PINCHTAB_TOKEN}`;
    }
  
    const url = `${PINCHTAB_URL}${path}`;
  
    let res: Response;
    try {
      res = await fetch(url, {
        body: body ? JSON.stringify(body) : undefined,
        headers,
        method,
        signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
      });
    } catch (error) {
      if (error instanceof DOMException && error.name === "TimeoutError") {
        throw new Error(`PinchTab ${method} ${path} timed out after ${REQUEST_TIMEOUT_MS / 1000}s`);
      }
      throw error;
    }
  
    if (!res.ok) {
      const text = await res.text();
      throw new Error(`PinchTab ${method} ${path} → ${res.status}: ${text}`);
    }
  
    const contentType = (res.headers.get("content-type") ?? "").split(";")[0].toLowerCase().trim();
    if (contentType === "application/json") {
      return res.json();
    }
    return res.text();
  }