shockbot/mcp/selectMode.ts

import { type } from "arktype";
import type { ToolContext } from "./server.ts";
import { execute, tool } from "./shared.ts";

export const SelectMode = type({
  modeName: type.string.describe(
    "the name of the mode to select (e.g., 'Plan', 'Build', 'Review', 'Prompt')"
  ),
});

export function SelectModeTool(ctx: ToolContext) {
  return tool({
    name: "select_mode",
    description:
      "Select a mode and get its detailed prompt instructions. Call this first to determine which mode to use based on the request.",
    parameters: SelectMode,
    execute: execute(async ({ modeName }) => {
      const selectedMode = ctx.modes.find((m) => m.name.toLowerCase() === modeName.toLowerCase());

      if (!selectedMode) {
        const availableModes = ctx.modes.map((m) => m.name).join(", ");
        return {
          error: `Mode "${modeName}" not found. Available modes: ${availableModes}`,
          availableModes: ctx.modes.map((m) => ({ name: m.name, description: m.description })),
        };
      }

      // store selected mode in toolState for use by other tools (e.g., report_progress)
      ctx.toolState.selectedMode = selectedMode.name;

      return {
        modeName: selectedMode.name,
        description: selectedMode.description,
        prompt: selectedMode.prompt,
      };
    }),
  });
}