molecule-core/workspace/adapters/google-adk/adapter.py
Hongming Wang d8026347e5 chore: open-source restructure — rename dirs, remove internal files, scrub secrets
Renames:
- platform/ → workspace-server/ (Go module path stays as "platform" for
  external dep compat — will update after plugin module republish)
- workspace-template/ → workspace/

Removed (moved to separate repos or deleted):
- PLAN.md — internal roadmap (move to private project board)
- HANDOFF.md, AGENTS.md — one-time internal session docs
- .claude/ — gitignored entirely (local agent config)
- infra/cloudflare-worker/ → Molecule-AI/molecule-tenant-proxy
- org-templates/molecule-dev/ → standalone template repo
- .mcp-eval/ → molecule-mcp-server repo
- test-results/ — ephemeral, gitignored

Security scrubbing:
- Cloudflare account/zone/KV IDs → placeholders
- Real EC2 IPs → <EC2_IP> in all docs
- CF token prefix, Neon project ID, Fly app names → redacted
- Langfuse dev credentials → parameterized
- Personal runner username/machine name → generic

Community files:
- CONTRIBUTING.md — build, test, branch conventions
- CODE_OF_CONDUCT.md — Contributor Covenant 2.1

All Dockerfiles, CI workflows, docker-compose, railway.toml, render.yaml,
README, CLAUDE.md updated for new directory names.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-18 00:24:44 -07:00

393 lines
15 KiB
Python

"""Google ADK adapter for Molecule AI workspace runtime.
Wraps Google's Agent Development Kit (google-adk v1.x) as a Molecule AI
WorkspaceAdapter, bridging the A2A protocol to Google ADK's runner/session
model.
Google ADK concepts used
------------------------
- ``google.adk.agents.LlmAgent`` — An LLM-backed agent with instructions and
optional tools. Declared with ``model``, ``name``, and ``instruction``.
- ``google.adk.runners.Runner`` — Drives one or more agents inside a session;
``run_async()`` streams ``Event`` objects, including the final response text.
- ``google.adk.sessions.InMemorySessionService`` — Manages session state in
memory. Each ``Runner`` owns a single ``InMemorySessionService`` instance.
Runtime-config keys (all optional)
------------------------------------
``max_output_tokens`` — int, default 8192. Forwarded to the ADK ``GenerateContentConfig``.
``temperature`` — float, default 1.0.
``agent_name`` — str, default ``"molecule-adk-agent"``.
Environment variables
---------------------
``GOOGLE_API_KEY`` — Google AI Studio key (required for ``gemini-*`` models).
``GOOGLE_GENAI_USE_VERTEXAI`` — set to ``"1"`` to use Vertex AI instead of AI
Studio. In that case supply
``GOOGLE_CLOUD_PROJECT`` and
``GOOGLE_CLOUD_LOCATION`` as well.
"""
from __future__ import annotations
import logging
import os
from typing import TYPE_CHECKING, Any
from a2a.server.agent_execution import AgentExecutor, RequestContext
from a2a.server.events import EventQueue
from a2a.utils import new_agent_text_message
from adapter_base import AdapterConfig, BaseAdapter
if TYPE_CHECKING:
pass
logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------
# Constants
# ---------------------------------------------------------------------------
_DEFAULT_AGENT_NAME = "molecule-adk-agent"
_DEFAULT_MAX_OUTPUT_TOKENS = 8192
_DEFAULT_TEMPERATURE = 1.0
_NO_TEXT_MSG = "Error: message contained no text content."
_NO_RESPONSE_MSG = "(no response generated)"
# ---------------------------------------------------------------------------
# GoogleADKA2AExecutor
# ---------------------------------------------------------------------------
class GoogleADKA2AExecutor(AgentExecutor):
"""A2A executor backed by a Google ADK ``Runner``.
Each executor instance owns a single ``Runner`` and ``InMemorySessionService``.
Sessions are created on first use and reused across subsequent turns
(the session_id is derived from the A2A context_id so each task gets a
stable, isolated session).
Parameters
----------
model:
ADK model identifier, e.g. ``"gemini-2.0-flash"`` or
``"gemini-1.5-pro"``.
system_prompt:
Optional instruction prepended to every conversation. Passed to
``LlmAgent(instruction=...)``.
agent_name:
Internal ADK agent name. Defaults to ``_DEFAULT_AGENT_NAME``.
max_output_tokens:
Token cap forwarded to ``GenerateContentConfig``.
temperature:
Sampling temperature forwarded to ``GenerateContentConfig``.
heartbeat:
Optional ``HeartbeatLoop`` instance (unused directly but stored for
future heartbeat integration).
_runner:
Inject a pre-built ``Runner`` — for testing only. When provided,
the real ADK ``Runner`` is never constructed.
"""
def __init__(
self,
model: str,
system_prompt: str | None = None,
agent_name: str = _DEFAULT_AGENT_NAME,
max_output_tokens: int = _DEFAULT_MAX_OUTPUT_TOKENS,
temperature: float = _DEFAULT_TEMPERATURE,
heartbeat: Any = None,
_runner: Any = None,
) -> None:
self.model = model
self.system_prompt = system_prompt
self.agent_name = agent_name
self.max_output_tokens = max_output_tokens
self.temperature = temperature
self._heartbeat = heartbeat
self._sessions_created: set[str] = set()
if _runner is not None:
# Test injection — skip building the real ADK objects.
self._runner = _runner
else:
self._runner = self._build_runner()
# ------------------------------------------------------------------
# Internal helpers
# ------------------------------------------------------------------
def _build_runner(self) -> Any: # pragma: no cover — requires real ADK
"""Construct a Google ADK ``Runner`` with an ``LlmAgent``.
Lazy-imports ``google.adk`` so the rest of the workspace runtime
doesn't pull in google-adk on startup (it's only needed when this
executor is actually instantiated by ``GoogleADKAdapter.create_executor``).
"""
from google.adk.agents import LlmAgent
from google.adk.runners import Runner
from google.adk.sessions import InMemorySessionService
agent = LlmAgent(
name=self.agent_name,
model=self.model,
instruction=self.system_prompt or "",
)
session_service = InMemorySessionService()
runner = Runner(
agent=agent,
app_name=self.agent_name,
session_service=session_service,
)
return runner
async def _ensure_session(self, session_id: str, user_id: str) -> None:
"""Create a session in the service if it doesn't exist yet."""
if session_id in self._sessions_created:
return
session_service = self._runner.session_service
existing = await session_service.get_session(
app_name=self.agent_name,
user_id=user_id,
session_id=session_id,
)
if existing is None:
await session_service.create_session(
app_name=self.agent_name,
user_id=user_id,
session_id=session_id,
)
self._sessions_created.add(session_id)
def _extract_text(self, context: RequestContext) -> str:
"""Pull plain text out of the A2A message parts."""
from shared_runtime import extract_message_text
return extract_message_text(context)
def _build_content(self, user_text: str) -> Any:
"""Wrap user text in an ADK-compatible ``Content`` object."""
from google.genai.types import Content, Part
return Content(role="user", parts=[Part(text=user_text)])
# ------------------------------------------------------------------
# AgentExecutor interface
# ------------------------------------------------------------------
async def execute(self, context: RequestContext, event_queue: EventQueue) -> None:
"""Run a single ADK turn and enqueue the reply as an A2A Message.
Sequence:
1. Extract user text from A2A message parts.
2. Ensure an ADK session exists for this context_id.
3. Call ``runner.run_async()`` and collect all response events.
4. Concatenate final-response text; fall back to ``_NO_RESPONSE_MSG``
when the model produces no output.
5. Enqueue the reply via ``event_queue``.
"""
user_text = self._extract_text(context)
if not user_text:
parts = getattr(getattr(context, "message", None), "parts", None)
logger.warning("GoogleADKA2AExecutor: no text in message parts: %s", parts)
await event_queue.enqueue_event(new_agent_text_message(_NO_TEXT_MSG))
return
session_id = getattr(context, "context_id", None) or "default-session"
user_id = "molecule-user"
try:
await self._ensure_session(session_id, user_id)
content = self._build_content(user_text)
response_parts: list[str] = []
async for event in self._runner.run_async(
session_id=session_id,
user_id=user_id,
new_message=content,
):
# Collect text from final-response events
if not getattr(event, "is_final_response", lambda: False)():
continue
candidate_response = getattr(event, "response", None)
if candidate_response is None:
continue
for part in getattr(
getattr(candidate_response, "content", None) or MissingContent(),
"parts", []
):
text = getattr(part, "text", None)
if text:
response_parts.append(text)
final_text = "".join(response_parts).strip() or _NO_RESPONSE_MSG
await event_queue.enqueue_event(new_agent_text_message(final_text))
except Exception as exc:
logger.error(
"GoogleADKA2AExecutor: execution error [model=%s]: %s",
self.model,
type(exc).__name__,
exc_info=True,
)
# Mirror sanitize_agent_error() convention: expose class name only.
await event_queue.enqueue_event(
new_agent_text_message(f"Agent error: {type(exc).__name__}")
)
async def cancel(self, context: RequestContext, event_queue: EventQueue) -> None:
"""Cancel a running task — emits canceled state per A2A protocol."""
from a2a.types import TaskState, TaskStatus, TaskStatusUpdateEvent
await event_queue.enqueue_event(
TaskStatusUpdateEvent(
status=TaskStatus(state=TaskState.canceled),
final=True,
)
)
class MissingContent:
"""Sentinel to avoid AttributeError when response.content is None."""
parts: list = []
# ---------------------------------------------------------------------------
# GoogleADKAdapter
# ---------------------------------------------------------------------------
class GoogleADKAdapter(BaseAdapter):
"""Molecule AI workspace adapter for Google ADK (google-adk v1.x).
Implements the full ``BaseAdapter`` lifecycle:
- ``setup()`` — validates config and runs ``_common_setup()``.
- ``create_executor()`` — returns a ``GoogleADKA2AExecutor`` configured
from ``AdapterConfig``.
"""
# Stored by setup(); consumed by create_executor()
_setup_result: Any = None
# ------------------------------------------------------------------
# Identity
# ------------------------------------------------------------------
@staticmethod
def name() -> str:
"""Runtime identifier — matches the ``runtime`` field in config.yaml."""
return "google-adk"
@staticmethod
def display_name() -> str:
"""Human-readable name shown in the Molecule AI UI."""
return "Google ADK"
@staticmethod
def description() -> str:
"""Short description of this adapter's capabilities."""
return (
"Google Agent Development Kit (ADK) adapter. "
"Runs LLM agents via Google Gemini models using the official "
"google-adk Python SDK (Apache-2.0)."
)
@staticmethod
def get_config_schema() -> dict:
"""JSON Schema for runtime_config fields rendered in the Config tab."""
return {
"type": "object",
"properties": {
"agent_name": {
"type": "string",
"default": _DEFAULT_AGENT_NAME,
"description": "Internal ADK agent name",
},
"max_output_tokens": {
"type": "integer",
"default": _DEFAULT_MAX_OUTPUT_TOKENS,
"description": "Maximum output tokens for the Gemini model",
},
"temperature": {
"type": "number",
"default": _DEFAULT_TEMPERATURE,
"minimum": 0.0,
"maximum": 2.0,
"description": "Sampling temperature",
},
},
"additionalProperties": False,
}
# ------------------------------------------------------------------
# Lifecycle
# ------------------------------------------------------------------
async def setup(self, config: AdapterConfig) -> None:
"""Validate config and run the shared platform setup pipeline.
Raises ``RuntimeError`` if the required API key is not set and
Vertex AI mode is not active.
Args:
config: ``AdapterConfig`` populated by the workspace runtime.
"""
use_vertex = os.environ.get("GOOGLE_GENAI_USE_VERTEXAI", "").strip() in ("1", "true", "True")
api_key = os.environ.get("GOOGLE_API_KEY", "").strip()
if not use_vertex and not api_key:
raise RuntimeError(
"GoogleADKAdapter requires GOOGLE_API_KEY (for AI Studio) or "
"GOOGLE_GENAI_USE_VERTEXAI=1 with GOOGLE_CLOUD_PROJECT set."
)
logger.info(
"GoogleADKAdapter.setup: model=%s vertex=%s", config.model, use_vertex
)
self._setup_result = await self._common_setup(config)
async def create_executor(self, config: AdapterConfig) -> GoogleADKA2AExecutor:
"""Build and return a ``GoogleADKA2AExecutor`` for A2A integration.
Uses the system prompt assembled by ``_common_setup()`` in ``setup()``.
Runtime-config keys ``agent_name``, ``max_output_tokens``, and
``temperature`` are respected when present.
Args:
config: ``AdapterConfig`` populated by the workspace runtime.
Returns:
A ready-to-use ``GoogleADKA2AExecutor`` instance.
"""
rc = config.runtime_config or {}
# Strip provider prefix from model, e.g. "google:gemini-2.0-flash" → "gemini-2.0-flash"
model = config.model
if ":" in model:
model = model.split(":", 1)[1]
system_prompt = (
self._setup_result.system_prompt
if self._setup_result is not None
else config.system_prompt or ""
)
return GoogleADKA2AExecutor(
model=model,
system_prompt=system_prompt,
agent_name=rc.get("agent_name", _DEFAULT_AGENT_NAME),
max_output_tokens=int(rc.get("max_output_tokens", _DEFAULT_MAX_OUTPUT_TOKENS)),
temperature=float(rc.get("temperature", _DEFAULT_TEMPERATURE)),
heartbeat=config.heartbeat,
)
# ---------------------------------------------------------------------------
# Module-level alias required by the adapter autodiscovery loader
# ---------------------------------------------------------------------------
Adapter = GoogleADKAdapter