Agent Skills with Google ADK and DNS Agent

Same agent, different framework

examples/demo_dns_adk.py implements exactly the same DNS Agent with the same 6 skills, but using Google ADK instead of SkillAgent. The behavior is identical — the difference is in the framework infrastructure.

Comparison: pure Python vs ADK

# ── Pure Python (skill_engine.py) ──────────────────────────────────────────
from skill_engine import SkillAgent
from dns_skills import list_dns_records, create_dns_record, ...

agent = SkillAgent(
    skills=[list_dns_records, create_dns_record, find_dns_record,
            update_dns_record, validate_dns, check_propagation],
    instructions="You are a DNS agent...",
    name="DNS Agent"
)
agent.run("Create api.yourdomain.com pointing to 203.0.113.50")


# ── Google ADK (demo_dns_adk.py) ────────────────────────────────────────────
from google.adk import Agent, Runner
from google.adk.sessions import InMemorySessionService
from dns_skills import list_dns_records, create_dns_record, ...

agent = Agent(
    name="dns_agent",
    model="gemini-2.5-flash",
    tools=[list_dns_records, create_dns_record, find_dns_record,
           update_dns_record, validate_dns, check_propagation],
    instruction="You are a DNS agent..."
)

session_service = InMemorySessionService()
runner = Runner(agent=agent, session_service=session_service, app_name="dns_demo")

The skills (dns_skills.py) are exactly the same Python functions in both cases — nothing needs to be rewritten.

ADK components

`Agent`

Defines the agent: model, tools and instructions.

agent = Agent(
    name="dns_agent",
    model="gemini-2.5-flash",
    tools=[...],           # The same Python functions from dns_skills.py
    instruction="..."      # System prompt — Layer 1
)

`Runner`

Orchestrates execution: connects the agent with the session service and manages the conversation cycle.

runner = Runner(
    agent=agent,
    session_service=session_service,
    app_name="dns_demo"
)

`InMemorySessionService`

Keeps conversation history in memory. ADK manages it automatically.

session_service = InMemorySessionService()
session = session_service.create_session(app_name="dns_demo", user_id="user")

Async execution

ADK uses asyncio. The main function is async:

import asyncio
from google.genai import types

async def run_agent(user_message: str):
    content = types.Content(
        role="user",
        parts=[types.Part(text=user_message)]
    )
    async for event in runner.run_async(
        user_id="user",
        session_id=session.id,
        new_message=content
    ):
        if event.is_final_response():
            print(event.content.parts[0].text)

asyncio.run(run_agent("Create api.yourdomain.com pointing to 203.0.113.50"))

Run the demo

python examples/demo_dns_adk.py --demo    # 3 pre-defined scenarios
python examples/demo_dns_adk.py           # interactive mode
python examples/demo_dns_adk.py "your request"  # direct mode

The output is equivalent to demo_dns.py — same scenarios, same behavior.

When to use ADK vs pure Python

	Pure Python (`SkillAgent`)	Google ADK
Dependencies	Only `google-genai`	Full `google-adk`
Session state	Doesn’t persist between calls	`InMemorySessionService` handles it
Multi-agent / A2A	Not native	Native support with `RemoteA2aAgent`
Ideal for	Simple scripts, quick demos	Production systems, A2A integration