haiku.rag/haiku_rag_slim/haiku/rag/graph/agui/emitter.py

385 lines
12 KiB
Python

"""Generic AG-UI event emitter for any graph execution."""
import asyncio
import hashlib
import json
from collections.abc import AsyncIterator
from typing import Any
from uuid import uuid4
from ag_ui.core import (
ActivitySnapshotEvent,
BaseEvent,
RunErrorEvent,
RunFinishedEvent,
RunStartedEvent,
StateDeltaEvent,
StateSnapshotEvent,
StepFinishedEvent,
StepStartedEvent,
TextMessageChunkEvent,
TextMessageContentEvent,
TextMessageEndEvent,
TextMessageStartEvent,
ToolCallArgsEvent,
ToolCallEndEvent,
ToolCallStartEvent,
)
from pydantic import BaseModel
from haiku.rag.graph.agui.state import compute_state_delta
AGUIEvent = dict[str, Any]
def _serialize_event(event: BaseEvent) -> AGUIEvent:
"""Serialize an ag_ui event to a dict with camelCase keys."""
return event.model_dump(mode="json", by_alias=True, exclude_none=True)
class AGUIEmitter[StateT: BaseModel, ResultT]:
"""Generic queue-backed AG-UI event emitter for any graph.
Manages the lifecycle of AG-UI events including:
- Run lifecycle (start, finish, error)
- Step lifecycle (start, finish)
- Text messages
- State synchronization (snapshots and deltas)
- Activity updates
Type parameters:
StateT: The Pydantic BaseModel type for graph state
ResultT: The result type returned by the graph
"""
def __init__(
self,
thread_id: str | None = None,
run_id: str | None = None,
use_deltas: bool = True,
):
"""Initialize the emitter.
Args:
thread_id: Optional thread ID (generated from input hash if not provided)
run_id: Optional run ID (random UUID if not provided)
use_deltas: Whether to emit state deltas instead of full snapshots (default: True)
"""
self._queue: asyncio.Queue[AGUIEvent | None] = asyncio.Queue()
self._closed = False
self._thread_id = thread_id or str(uuid4())
self._run_id = run_id or str(uuid4())
self._last_state: StateT | None = None
self._active_steps: set[str] = set()
self._use_deltas = use_deltas
@property
def thread_id(self) -> str:
"""Get the thread ID for this emitter."""
return self._thread_id
@property
def run_id(self) -> str:
"""Get the run ID for this emitter."""
return self._run_id
def start_run(self, initial_state: StateT) -> None:
"""Emit RunStarted and initial StateSnapshot.
Args:
initial_state: The initial state of the graph
"""
# If thread_id wasn't provided, generate from state hash
if not self._thread_id or self._thread_id == str(uuid4()):
state_json = initial_state.model_dump_json()
self._thread_id = self._generate_thread_id(state_json)
# RunStarted (state snapshot follows immediately with full state)
self.emit(
_serialize_event(
RunStartedEvent(thread_id=self._thread_id, run_id=self._run_id)
)
)
self.emit(
_serialize_event(StateSnapshotEvent(snapshot=initial_state.model_dump()))
)
# Store a deep copy to detect future changes
self._last_state = initial_state.model_copy(deep=True)
def start_step(self, step_name: str) -> None:
"""Emit StepStarted event.
Args:
step_name: Name of the step being started
"""
self._active_steps.add(step_name)
self.emit(_serialize_event(StepStartedEvent(step_name=step_name)))
def finish_step(self, step_name: str) -> None:
"""Emit StepFinished event for the specified step.
Args:
step_name: Name of the step being finished
"""
self._active_steps.discard(step_name)
self.emit(_serialize_event(StepFinishedEvent(step_name=step_name)))
def log(self, message: str, role: str = "assistant") -> None:
"""Emit a text message event.
Args:
message: The message content
role: The role of the sender (default: assistant)
"""
message_id = str(uuid4())
self.emit(
_serialize_event(
TextMessageChunkEvent(
message_id=message_id,
role=role, # type: ignore[arg-type]
delta=message,
)
)
)
def update_state(self, new_state: StateT) -> None:
"""Emit StateDelta or StateSnapshot for state change.
Args:
new_state: The updated state
"""
if self._use_deltas and self._last_state is not None:
# Emit delta for incremental updates
delta = compute_state_delta(self._last_state, new_state)
self.emit(_serialize_event(StateDeltaEvent(delta=delta)))
else:
# Emit full snapshot for initial state or when deltas disabled
self.emit(
_serialize_event(StateSnapshotEvent(snapshot=new_state.model_dump()))
)
# Store a deep copy to detect future changes
self._last_state = new_state.model_copy(deep=True)
def update_activity(
self,
activity_type: str,
content: dict[str, Any],
message_id: str | None = None,
) -> None:
"""Emit ActivitySnapshot event.
Args:
activity_type: Type of activity (e.g., "planning", "searching")
content: Structured payload representing the activity state
message_id: Optional message ID to associate activity with (auto-generated if None)
"""
if message_id is None:
message_id = str(uuid4())
self.emit(
_serialize_event(
ActivitySnapshotEvent(
message_id=message_id,
activity_type=activity_type,
content=content,
)
)
)
def finish_run(self, result: ResultT) -> None:
"""Emit RunFinished event.
Args:
result: The final result from the graph
"""
# Convert result to dict if it's a Pydantic model
result_data: Any = result
if hasattr(result, "model_dump"):
result_data = result.model_dump() # type: ignore[union-attr]
self.emit(
_serialize_event(
RunFinishedEvent(
thread_id=self._thread_id, run_id=self._run_id, result=result_data
)
)
)
def error(self, error: Exception, code: str | None = None) -> None:
"""Emit RunError event.
Args:
error: The exception that occurred
code: Optional error code
"""
self.emit(_serialize_event(RunErrorEvent(message=str(error), code=code)))
def emit(self, event: AGUIEvent) -> None:
"""Put event in queue.
Args:
event: The event to emit
"""
if not self._closed:
self._queue.put_nowait(event)
async def close(self) -> None:
"""Close the emitter and stop event iteration."""
if self._closed:
return
self._closed = True
await self._queue.put(None)
def __aiter__(self) -> AsyncIterator[AGUIEvent]:
"""Enable async iteration over events."""
return self._iter_events()
async def _iter_events(self) -> AsyncIterator[AGUIEvent]:
"""Iterate over events from the queue."""
while True:
event = await self._queue.get()
if event is None:
break
yield event
@staticmethod
def _generate_thread_id(input_data: str) -> str:
"""Generate a deterministic thread ID from input data.
Args:
input_data: The input data (e.g., question, prompt)
Returns:
A stable thread ID based on input hash
"""
# Use hash of input for deterministic thread ID
hash_obj = hashlib.sha256(input_data.encode("utf-8"))
return hash_obj.hexdigest()[:16]
def emit_text_message_start(message_id: str, role: str = "assistant") -> AGUIEvent:
"""Create a TextMessageStart event."""
return _serialize_event(
TextMessageStartEvent(message_id=message_id, role=role) # type: ignore[arg-type]
)
def emit_text_message_content(message_id: str, delta: str) -> AGUIEvent:
"""Create a TextMessageContent event."""
return _serialize_event(TextMessageContentEvent(message_id=message_id, delta=delta))
def emit_text_message_end(message_id: str) -> AGUIEvent:
"""Create a TextMessageEnd event."""
return _serialize_event(TextMessageEndEvent(message_id=message_id))
def emit_tool_call_start(
tool_call_id: str,
tool_name: str,
parent_message_id: str | None = None,
) -> AGUIEvent:
"""Create a ToolCallStart event."""
return _serialize_event(
ToolCallStartEvent(
tool_call_id=tool_call_id,
tool_call_name=tool_name,
parent_message_id=parent_message_id,
)
)
def emit_tool_call_args(tool_call_id: str, args: dict[str, Any]) -> AGUIEvent:
"""Create a ToolCallArgs event."""
return _serialize_event(
ToolCallArgsEvent(tool_call_id=tool_call_id, delta=json.dumps(args))
)
def emit_tool_call_end(tool_call_id: str) -> AGUIEvent:
"""Create a ToolCallEnd event."""
return _serialize_event(ToolCallEndEvent(tool_call_id=tool_call_id))
def emit_run_started(thread_id: str, run_id: str) -> AGUIEvent:
"""Create a RunStarted event."""
return _serialize_event(RunStartedEvent(thread_id=thread_id, run_id=run_id))
def emit_run_finished(thread_id: str, run_id: str, result: Any) -> AGUIEvent:
"""Create a RunFinished event."""
# Convert result to dict if it's a Pydantic model
if hasattr(result, "model_dump"):
result = result.model_dump()
return _serialize_event(
RunFinishedEvent(thread_id=thread_id, run_id=run_id, result=result)
)
def emit_run_error(message: str, code: str | None = None) -> AGUIEvent:
"""Create a RunError event."""
return _serialize_event(RunErrorEvent(message=message, code=code))
def emit_step_started(step_name: str) -> AGUIEvent:
"""Create a StepStarted event."""
return _serialize_event(StepStartedEvent(step_name=step_name))
def emit_step_finished(step_name: str) -> AGUIEvent:
"""Create a StepFinished event."""
return _serialize_event(StepFinishedEvent(step_name=step_name))
def emit_text_message(content: str, role: str = "assistant") -> AGUIEvent:
"""Create a TextMessageChunk event (convenience wrapper)."""
message_id = str(uuid4())
return _serialize_event(
TextMessageChunkEvent(
message_id=message_id,
role=role, # type: ignore[arg-type]
delta=content,
)
)
def emit_state_snapshot(state: BaseModel) -> AGUIEvent:
"""Create a StateSnapshot event."""
return _serialize_event(StateSnapshotEvent(snapshot=state.model_dump()))
def emit_state_delta(old_state: BaseModel, new_state: BaseModel) -> AGUIEvent:
"""Create a StateDelta event with JSON Patch operations."""
delta = compute_state_delta(old_state, new_state)
return _serialize_event(StateDeltaEvent(delta=delta))
def emit_activity(
message_id: str,
activity_type: str,
content: dict[str, Any],
) -> AGUIEvent:
"""Create an ActivitySnapshot event."""
return _serialize_event(
ActivitySnapshotEvent(
message_id=message_id,
activity_type=activity_type,
content=content,
)
)
def emit_activity_delta(
message_id: str,
activity_type: str,
patch: list[dict[str, Any]],
) -> AGUIEvent:
"""Create an ActivityDelta event with JSON Patch operations."""
from ag_ui.core import ActivityDeltaEvent
return _serialize_event(
ActivityDeltaEvent(
message_id=message_id,
activity_type=activity_type,
patch=patch,
)
)