haiku.rag/haiku_rag_slim/haiku/rag/graph/agui/server.py
2025-12-18 12:07:37 +02:00

268 lines
8.3 KiB
Python

"""AG-UI HTTP server implementation for graph execution."""
import json
from collections.abc import AsyncIterator, Callable
from pathlib import Path
from typing import TYPE_CHECKING, Any, Protocol
if TYPE_CHECKING:
from haiku.rag.config.models import AppConfig
from pydantic import BaseModel, Field
from pydantic_graph.beta import Graph
from starlette.applications import Starlette
from starlette.middleware import Middleware
from starlette.middleware.cors import CORSMiddleware
from starlette.requests import Request
from starlette.responses import JSONResponse, StreamingResponse
from starlette.routing import Route
from haiku.rag.config.models import AGUIConfig
from haiku.rag.graph.agui.emitter import AGUIEmitter, AGUIEvent
from haiku.rag.graph.agui.stream import stream_graph
class GraphDeps(Protocol):
"""Protocol for graph dependencies that support AG-UI emission."""
agui_emitter: AGUIEmitter[Any, Any] | None
class RunAgentInput(BaseModel):
"""AG-UI protocol run agent input.
See: https://docs.ag-ui.com/concepts/agents#runagentinput
"""
thread_id: str | None = Field(None, alias="threadId")
run_id: str | None = Field(None, alias="runId")
state: dict[str, Any] = Field(default_factory=dict)
messages: list[dict[str, Any]] = Field(default_factory=list)
config: dict[str, Any] = Field(default_factory=dict)
def create_agui_app(
graph_factory: Callable[[], Graph],
state_factory: Callable[[dict[str, Any]], BaseModel],
deps_factory: Callable[[dict[str, Any]], GraphDeps],
config: AGUIConfig,
) -> Starlette:
"""Create Starlette app with AG-UI endpoint.
Args:
graph_factory: Factory function to create graph instance
state_factory: Factory to create initial state from input
deps_factory: Factory to create graph dependencies
config: AG-UI server configuration
Returns:
Starlette application with AG-UI endpoints
"""
async def event_stream(
input_data: RunAgentInput,
) -> AsyncIterator[str]:
"""Generate SSE event stream from graph execution.
Yields:
Server-Sent Events formatted strings
"""
# Create graph, state, and dependencies
graph = graph_factory()
# Create initial state from input
initial_state = state_factory(input_data.state)
# Create dependencies (may use config from input)
deps = deps_factory(input_data.config)
# Execute graph and stream events
async for event in stream_graph(graph, initial_state, deps):
# Format as SSE event
event_data = format_sse_event(event)
yield event_data
async def stream_agent(request: Request) -> StreamingResponse:
"""AG-UI agent stream endpoint.
Accepts AG-UI RunAgentInput and streams events via SSE.
"""
# Parse request body
body = await request.json()
input_data = RunAgentInput(**body)
# Return SSE stream
return StreamingResponse(
event_stream(input_data),
media_type="text/event-stream",
headers={
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no", # Disable buffering in nginx
},
)
async def health_check(_: Request) -> JSONResponse:
"""Health check endpoint."""
return JSONResponse({"status": "healthy"})
# Define routes
routes = [
Route("/v1/agent/stream", stream_agent, methods=["POST"]),
Route("/health", health_check, methods=["GET"]),
]
# Configure CORS middleware
middleware = [
Middleware(
CORSMiddleware,
allow_origins=config.cors_origins,
allow_credentials=config.cors_credentials,
allow_methods=config.cors_methods,
allow_headers=config.cors_headers,
)
]
# Create Starlette app
app = Starlette(
routes=routes,
middleware=middleware,
debug=False,
)
return app
def format_sse_event(event: AGUIEvent) -> str:
"""Format AG-UI event as Server-Sent Event.
Args:
event: AG-UI event dictionary
Returns:
SSE formatted string with event data
"""
# Convert event to JSON
event_json = json.dumps(event, ensure_ascii=False)
# Format as SSE
# Each event is: data: <json>\n\n
return f"data: {event_json}\n\n"
def create_agui_server( # pragma: no cover
config: "AppConfig", db_path: Path | None = None
) -> Starlette:
"""Create AG-UI server with research endpoint.
Args:
config: Application config with research settings
db_path: Optional database path override
Returns:
Starlette app with research endpoint
"""
from haiku.rag.client import HaikuRAG
from haiku.rag.graph.research.dependencies import ResearchContext
from haiku.rag.graph.research.graph import build_research_graph
from haiku.rag.graph.research.state import (
ResearchDeps,
ResearchState,
)
# Store client reference for proper lifecycle management
_client_cache: dict[str, HaikuRAG] = {}
def get_client(effective_db_path: Path) -> HaikuRAG:
"""Get or create cached client."""
path_key = str(effective_db_path)
if path_key not in _client_cache:
_client_cache[path_key] = HaikuRAG(db_path=effective_db_path, config=config)
return _client_cache[path_key]
# Research graph factories
def research_graph_factory() -> Graph:
return build_research_graph(config)
def research_state_factory(input_state: dict[str, Any]) -> ResearchState:
question = input_state.get("question", "")
if not question:
messages = input_state.get("messages", [])
if messages:
question = messages[0].get("content", "")
context = ResearchContext(original_question=question)
max_iterations = input_state.get("max_iterations")
confidence_threshold = input_state.get("confidence_threshold")
return ResearchState.from_config(
context=context,
config=config,
max_iterations=max_iterations,
confidence_threshold=confidence_threshold,
)
def research_deps_factory(input_config: dict[str, Any]) -> ResearchDeps:
effective_db_path = (
db_path
or input_config.get("db_path")
or config.storage.data_dir / "haiku.rag.lancedb"
)
return ResearchDeps(client=get_client(effective_db_path))
# Create event stream function
async def research_event_stream(
input_data: RunAgentInput,
) -> AsyncIterator[str]:
"""Generate SSE event stream from research graph execution."""
graph = research_graph_factory()
initial_state = research_state_factory(input_data.state)
deps = research_deps_factory(input_data.config)
async for event in stream_graph(graph, initial_state, deps):
event_data = format_sse_event(event)
yield event_data
# Endpoint handlers
async def stream_research(request: Request) -> StreamingResponse:
"""Research graph streaming endpoint."""
body = await request.json()
input_data = RunAgentInput(**body)
return StreamingResponse(
research_event_stream(input_data),
media_type="text/event-stream",
headers={
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no",
},
)
async def health_check(_: Request) -> JSONResponse:
"""Health check endpoint."""
return JSONResponse({"status": "healthy"})
# Define routes
routes = [
Route("/v1/research/stream", stream_research, methods=["POST"]),
Route("/health", health_check, methods=["GET"]),
]
# Configure CORS middleware
middleware = [
Middleware(
CORSMiddleware,
allow_origins=config.agui.cors_origins,
allow_credentials=config.agui.cors_credentials,
allow_methods=config.agui.cors_methods,
allow_headers=config.agui.cors_headers,
)
]
# Create Starlette app
app = Starlette(
routes=routes,
middleware=middleware,
debug=False,
)
return app