Bonus Patterns

export type ExtensionHandler<E, R = undefined> = (event: E, ctx: ExtensionContext) => Promise<R | void> | R | void;

execute(
  toolCallId: string,
  params: Static<TParams>,  // Infers TS type from TypeBox schema
  signal: AbortSignal | undefined,
  onUpdate: AgentToolUpdateCallback<TDetails> | undefined,
  ctx: ExtensionContext,
): Promise<AgentToolResult<TDetails>>;

export interface ExtensionCommandContext extends ExtensionContext {
  waitForIdle(): Promise<void>;
  newSession(options?: { /* ... */ }): Promise<{ cancelled: boolean }>;
  fork(entryId: string): Promise<{ cancelled: boolean }>;
  // ...
}

interface ToolCallEventBase {
  type: "tool_call";
  toolCallId: string;
}

export interface BashToolCallEvent extends ToolCallEventBase {
  toolName: "bash";
  input: BashToolInput;
}

export interface ReadToolCallEvent extends ToolCallEventBase {
  toolName: "read";
  input: ReadToolInput;
}

// Union of all specialized tool events
export type ToolCallEvent = BashToolCallEvent | ReadToolCallEvent | EditToolCallEvent | WriteToolCallEvent | CustomToolCallEvent;