step 3 complete: pluggable agent framework

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-03-02 00:03:42 +01:00
parent 82669d3704
commit 0d16729036
3 changed files with 354 additions and 3 deletions

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@@ -112,8 +112,8 @@ adiuva-api/
- `UserProfile`: `id: str`, `email: str`, `tier: BillingTier`
- **Outcome:** All request/response models defined and validated.
### Step 3 — Agent Registry + base classes
- [ ] `app/core/agent_registry.py`:
### Step 3 — Agent Registry + base classes
- [x] `app/core/agent_registry.py`:
- `BaseAgent(ABC)`:
- `user_id: str`, `shared_memory: dict`, `vector_store_context: list[str]`, `skills: list[str]`
- Abstract `get_name() -> str`, `get_description() -> str`
@@ -127,7 +127,7 @@ adiuva-api/
- `get(name) -> ChatAgent`
- `list_agents() -> list[dict]` — returns `[{name, description}]` for orchestrator prompt
- `async call_agent(name, query, context) -> str` — for inter-agent calls
- [ ] Unit tests: register, get, list, call_agent with mock
- [x] Unit tests: register, get, list, call_agent with mock
- **Outcome:** Pluggable agent framework.
### Step 4 — Orchestrator

137
app/core/agent_registry.py Normal file
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@@ -0,0 +1,137 @@
"""Agent Registry — base classes and singleton registry for chat agents."""
from __future__ import annotations
from abc import ABC, abstractmethod
from typing import Any
class BaseAgent(ABC):
"""Common base for all agents."""
def __init__(
self,
user_id: str = "",
shared_memory: dict[str, Any] | None = None,
vector_store_context: list[str] | None = None,
) -> None:
self.user_id = user_id
self.shared_memory: dict[str, Any] = shared_memory or {}
self.vector_store_context: list[str] = vector_store_context or []
@abstractmethod
def get_name(self) -> str: ...
@abstractmethod
def get_description(self) -> str: ...
@property
def skills(self) -> list[str]:
"""Override in subclasses to advertise capabilities."""
return []
class ChatAgent(BaseAgent):
"""Base class for LLM-powered chat agents."""
@abstractmethod
async def handle(self, query: str, context: dict[str, Any]) -> str:
"""Process a user query and return a text response."""
...
@abstractmethod
def get_tools(self) -> list[Any]:
"""Return LangChain tool definitions available to this agent."""
...
async def _tool_loop(
self,
llm: Any,
messages: list[Any],
tools: list[Any],
max_iter: int = 5,
) -> str:
"""Shared tool-calling loop.
Binds *tools* to *llm*, invokes iteratively until the model stops
requesting tool calls or *max_iter* is reached, and returns the
final text response.
"""
from langchain_core.messages import AIMessage, ToolMessage
llm_with_tools = llm.bind_tools(tools) if tools else llm
for _ in range(max_iter):
response: AIMessage = await llm_with_tools.ainvoke(messages)
messages.append(response)
if not response.tool_calls:
return str(response.content)
# Execute each requested tool call
tool_map = {t.name: t for t in tools}
for call in response.tool_calls:
tool_fn = tool_map.get(call["name"])
if tool_fn is None:
result = f"Unknown tool: {call['name']}"
else:
result = await tool_fn.ainvoke(call["args"])
messages.append(
ToolMessage(content=str(result), tool_call_id=call["id"])
)
# Exhausted iterations — ask model for a final answer without tools
response = await llm.ainvoke(messages)
return str(response.content)
class AgentRegistry:
"""Singleton registry for ChatAgent subclasses."""
_instance: AgentRegistry | None = None
def __init__(self) -> None:
self._agents: dict[str, type[ChatAgent]] = {}
def __new__(cls) -> AgentRegistry:
if cls._instance is None:
cls._instance = super().__new__(cls)
cls._instance._agents = {}
return cls._instance
# ── public API ───────────────────────────────────────────────────
def register(self, agent_class: type[ChatAgent]) -> type[ChatAgent]:
"""Class decorator — registers an agent by its name."""
instance = agent_class()
name = instance.get_name()
self._agents[name] = agent_class
return agent_class
def get(self, name: str) -> ChatAgent:
"""Return a fresh instance of the named agent."""
cls = self._agents.get(name)
if cls is None:
raise KeyError(f"Agent not found: {name}")
return cls()
def list_agents(self) -> list[dict[str, str]]:
"""Return ``[{name, description}]`` for the orchestrator prompt."""
result: list[dict[str, str]] = []
for cls in self._agents.values():
inst = cls()
result.append(
{"name": inst.get_name(), "description": inst.get_description()}
)
return result
async def call_agent(
self, name: str, query: str, context: dict[str, Any]
) -> str:
"""Instantiate the named agent and call its ``handle`` method."""
agent = self.get(name)
return await agent.handle(query, context)
# Module-level singleton
registry = AgentRegistry()

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@@ -0,0 +1,214 @@
"""Unit tests for the agent registry, base classes, and tool loop."""
from __future__ import annotations
from typing import Any
from unittest.mock import AsyncMock, MagicMock
import pytest
from app.core.agent_registry import AgentRegistry, ChatAgent
# ── Helpers ──────────────────────────────────────────────────────────
class _StubAgent(ChatAgent):
"""Minimal concrete agent for testing."""
def get_name(self) -> str:
return "stub"
def get_description(self) -> str:
return "A stub agent for tests"
def get_tools(self) -> list[Any]:
return []
async def handle(self, query: str, context: dict[str, Any]) -> str:
return f"echo: {query}"
class _AnotherAgent(ChatAgent):
def get_name(self) -> str:
return "another"
def get_description(self) -> str:
return "Another stub"
def get_tools(self) -> list[Any]:
return []
async def handle(self, query: str, context: dict[str, Any]) -> str:
return "another"
# ── Fixtures ─────────────────────────────────────────────────────────
@pytest.fixture(autouse=True)
def _fresh_registry():
"""Reset the singleton between tests."""
AgentRegistry._instance = None
yield
AgentRegistry._instance = None
@pytest.fixture()
def reg() -> AgentRegistry:
return AgentRegistry()
# ── Tests ────────────────────────────────────────────────────────────
class TestRegisterAndGet:
def test_register_decorator(self, reg: AgentRegistry) -> None:
reg.register(_StubAgent)
agent = reg.get("stub")
assert isinstance(agent, _StubAgent)
def test_get_unknown_raises(self, reg: AgentRegistry) -> None:
with pytest.raises(KeyError, match="not found"):
reg.get("nonexistent")
def test_register_multiple(self, reg: AgentRegistry) -> None:
reg.register(_StubAgent)
reg.register(_AnotherAgent)
assert reg.get("stub").get_name() == "stub"
assert reg.get("another").get_name() == "another"
class TestListAgents:
def test_empty(self, reg: AgentRegistry) -> None:
assert reg.list_agents() == []
def test_list_after_register(self, reg: AgentRegistry) -> None:
reg.register(_StubAgent)
agents = reg.list_agents()
assert len(agents) == 1
assert agents[0] == {"name": "stub", "description": "A stub agent for tests"}
def test_list_multiple(self, reg: AgentRegistry) -> None:
reg.register(_StubAgent)
reg.register(_AnotherAgent)
names = {a["name"] for a in reg.list_agents()}
assert names == {"stub", "another"}
class TestCallAgent:
@pytest.mark.asyncio
async def test_call_agent(self, reg: AgentRegistry) -> None:
reg.register(_StubAgent)
result = await reg.call_agent("stub", "hello", {})
assert result == "echo: hello"
@pytest.mark.asyncio
async def test_call_unknown_raises(self, reg: AgentRegistry) -> None:
with pytest.raises(KeyError):
await reg.call_agent("nope", "hi", {})
class TestSingleton:
def test_singleton_identity(self) -> None:
a = AgentRegistry()
b = AgentRegistry()
assert a is b
class TestToolLoop:
@pytest.mark.asyncio
async def test_no_tool_calls(self) -> None:
"""When the LLM responds without tool calls, return content directly."""
agent = _StubAgent()
ai_msg = MagicMock()
ai_msg.content = "final answer"
ai_msg.tool_calls = []
llm = AsyncMock()
llm.bind_tools = MagicMock(return_value=llm)
llm.ainvoke = AsyncMock(return_value=ai_msg)
result = await agent._tool_loop(llm, [], [])
assert result == "final answer"
@pytest.mark.asyncio
async def test_tool_call_then_answer(self) -> None:
"""LLM requests one tool call, gets result, then answers."""
agent = _StubAgent()
# First response: tool call
tool_call_msg = MagicMock()
tool_call_msg.content = ""
tool_call_msg.tool_calls = [
{"id": "call_1", "name": "my_tool", "args": {"x": 1}}
]
# Second response: final answer
final_msg = MagicMock()
final_msg.content = "done"
final_msg.tool_calls = []
llm = AsyncMock()
llm.bind_tools = MagicMock(return_value=llm)
llm.ainvoke = AsyncMock(side_effect=[tool_call_msg, final_msg])
# Mock tool
tool = AsyncMock()
tool.name = "my_tool"
tool.ainvoke = AsyncMock(return_value="tool_result")
result = await agent._tool_loop(llm, [], [tool])
assert result == "done"
tool.ainvoke.assert_called_once_with({"x": 1})
@pytest.mark.asyncio
async def test_unknown_tool_handled(self) -> None:
"""Unknown tool names produce an error message instead of crashing."""
agent = _StubAgent()
tool_call_msg = MagicMock()
tool_call_msg.content = ""
tool_call_msg.tool_calls = [
{"id": "call_1", "name": "missing", "args": {}}
]
final_msg = MagicMock()
final_msg.content = "recovered"
final_msg.tool_calls = []
llm = AsyncMock()
llm.bind_tools = MagicMock(return_value=llm)
llm.ainvoke = AsyncMock(side_effect=[tool_call_msg, final_msg])
result = await agent._tool_loop(llm, [], [])
assert result == "recovered"
@pytest.mark.asyncio
async def test_max_iter_reached(self) -> None:
"""When max iterations are exhausted, a final no-tools call is made."""
agent = _StubAgent()
# Every response requests a tool call
loop_msg = MagicMock()
loop_msg.content = ""
loop_msg.tool_calls = [
{"id": "call_x", "name": "t", "args": {}}
]
final_msg = MagicMock()
final_msg.content = "gave up"
final_msg.tool_calls = []
tool = AsyncMock()
tool.name = "t"
tool.ainvoke = AsyncMock(return_value="ok")
llm_with_tools = AsyncMock()
llm_with_tools.ainvoke = AsyncMock(return_value=loop_msg)
llm = AsyncMock()
llm.bind_tools = MagicMock(return_value=llm_with_tools)
llm.ainvoke = AsyncMock(return_value=final_msg)
result = await agent._tool_loop(llm, [], [tool], max_iter=2)
assert result == "gave up"
assert llm_with_tools.ainvoke.call_count == 2