List physical devices and simulators

Instructions

Implementation Reference

• src/tools/listTraceDevices.ts:62-78 (handler)

  Main handler: runs `xcrun xctrace list devices`, parses output, optionally filters offline devices, returns list of devices with UDIDs.

  export async function listTraceDevices(
    input: ListTraceDevicesInput,
  ): Promise<ListTraceDevicesResult> {
    const result = await runCommand("xcrun", ["xctrace", "list", "devices"], {
      timeoutMs: 30_000,
    });
    if (result.code !== 0) {
      throw new Error(
        `xctrace list devices failed (code ${result.code}): ${result.stderr || result.stdout}`,
      );
    }
    let devices = parseDeviceListing(result.stdout);
    if (!input.includeOffline) {
      devices = devices.filter((d) => d.kind !== "device-offline");
    }
    return { ok: true, devices };
  }

• src/tools/listTraceDevices.ts:4-9 (schema)

  Input schema: accepts optional `includeOffline` boolean (default false).

  export const listTraceDevicesSchema = z.object({
    includeOffline: z
      .boolean()
      .default(false)
      .describe("Include devices listed under \"Devices Offline\" (default false)."),
  });

• src/tools/listTraceDevices.ts:13-26 (schema)

  Output types: DeviceKind, TraceDevice interface, and ListTraceDevicesResult interface.

  export type DeviceKind = "device" | "device-offline" | "simulator";
  
  export interface TraceDevice {
    kind: DeviceKind;
    name: string;
    /** OS version when the listing carries one (e.g. "26.3.1"). */
    osVersion?: string;
    udid: string;
  }
  
  export interface ListTraceDevicesResult {
    ok: boolean;
    devices: TraceDevice[];
  }

• src/tools/listTraceDevices.ts:38-60 (helper)

  Pure parser function: parses the raw text output of `xctrace list devices` into structured TraceDevice objects.

  export function parseDeviceListing(text: string): TraceDevice[] {
    const lines = text.split(/\r?\n/);
    let kind: DeviceKind | null = null;
    const devices: TraceDevice[] = [];
    for (const raw of lines) {
      const line = raw.trim();
      if (!line) continue;
      if (line in SECTION_TO_KIND) {
        kind = SECTION_TO_KIND[line];
        continue;
      }
      if (!kind) continue;
      const m = line.match(LINE_RE);
      if (!m) continue;
      devices.push({
        kind,
        name: m[1].trim(),
        osVersion: m[2],
        udid: m[3],
      });
    }
    return devices;
  }

• src/index.ts:249-263 (registration)

  Registration of the tool 'listTraceDevices' in the MCP server with title, description, input schema, and handler wrapper.

  server.registerTool(
    "listTraceDevices",
    {
      title: "List physical devices and simulators",
      description:
        "[mg.discover] Run `xcrun xctrace list devices` and return parsed devices/simulators with their UDIDs. The LLM should call this before `recordTimeProfile` to discover the right UDID without asking the user. Set `includeOffline: true` to include disconnected devices.",
      inputSchema: listTraceDevicesSchema.shape,
    },
    async (input) => {
      const result = await listTraceDevices(input);
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
      };
    },
  );