HITL Overview

"""ADK agent backing the In-Chat HITL (book_call) demo.

The `book_call` tool is defined on the frontend via `useHumanInTheLoop`, so
there is no backend tool implementation here — the frontend renders a time
picker, the user's choice is forwarded back to the agent as the tool result.

This mirrors the langgraph-python reference (hitl_in_chat_agent.py) but
adapted to ADK: ADK doesn't need an explicit tool stub on the backend for
frontend-defined tools — the ag-ui-adk middleware injects the frontend's
tool list at request time.
"""

from __future__ import annotations

from google.adk.agents import LlmAgent
from ag_ui_adk import AGUIToolset

from agents.shared_chat import get_model, stop_on_terminal_text

_INSTRUCTION = (
    "You help users book an onboarding call with the sales team. "
    "When they ask to book a call, call the frontend-provided "
    "`book_call` tool with a short topic and the user's name. "
    "Keep any chat reply to one short sentence."
)

hitl_in_chat_book_call_agent = LlmAgent(
    name="HitlInChatBookCallAgent",
    model=get_model(),
    instruction=_INSTRUCTION,
    tools=[AGUIToolset()],
    after_model_callback=stop_on_terminal_text,
)

"""ADK scheduling agent backing the gen-ui-interrupt demo (Strategy-B).In langgraph-python the gen-ui-interrupt demo relies on the native`interrupt()` primitive with checkpoint/resume. ADK has no such primitive,so we adapt with the same "Strategy B" pattern used by the agno andms-agent-framework ports: the agent's instruction tells Gemini to call the`schedule_meeting` tool, but NO backend tool is registered. CopilotKit's`AGUIToolset()` injects the frontend-registered `schedule_meeting`(`useHumanInTheLoop` in src/app/demos/gen-ui-interrupt/page.tsx) into themodel's tool list; the model's call is routed to the frontend, which rendersthe time-picker inline and resolves the call once the user picks a slot —equivalent to `interrupt()` in the LangGraph reference.`after_model_callback=stop_on_terminal_text` is the canonical ADK terminalguard (see shared_chat.py): without it the configured Gemini model(from `get_model()`) re-issues the same tool call indefinitely after thefrontend tool resolves."""from __future__ import annotations# region: setupfrom google.adk.agents import LlmAgentfrom ag_ui_adk import AGUIToolsetfrom agents.shared_chat import get_model, stop_on_terminal_text_INSTRUCTION = (    "You are a scheduling assistant. Whenever the user asks you to book a "    "call or schedule a meeting, you MUST call the `schedule_meeting` tool. "    "Pass a short `topic` describing the purpose of the meeting and, if "    "known, an `attendee` describing who the meeting is with.\n\n"    "The `schedule_meeting` tool is implemented on the client: it surfaces a "    "time-picker UI and returns the user's selection. After the tool "    "returns, briefly confirm whether the meeting was scheduled and at what "    "time, or note that the user cancelled. Do NOT ask for approval "    "yourself — always call the tool and let the picker handle the decision. "    "Keep responses short and friendly, and always send a brief final "    "assistant message summarising what happened so it persists.")interrupt_agent = LlmAgent(    name="InterruptAgent",    model=get_model(),    instruction=_INSTRUCTION,    # No backend tools. `schedule_meeting` is registered on the frontend via    # useHumanInTheLoop; AGUIToolset() exposes CopilotKit's frontend-tool    # channel to the model.    tools=[AGUIToolset()],    after_model_callback=stop_on_terminal_text,)# endregion