haiku.rag/examples/custom_agent_agui.py
Yiorgis Gozadinos a04a16c717
Remove the environment overrides and the last unnamed-database wording
HAIKU_RAG_DB and DB_PATH are gone: a capability covers what the
configuration places or the db_path it is given, and the app backend and
the AG-UI example load their configuration as the CLI does. The compose
files point HAIKU_RAG_CONFIG_PATH at the mounted haiku.rag.yaml, which
places the database at /data where DB_VOLUME is mounted; the backend
refuses a configured set since it serves one database. The chat scopes a
selection by source only over a set and names databases on filter rows
only across several. Docstrings, docs and test fixtures stop describing an
unnamed database; every database a search, listing or citation reports
carries a name.
2026-09-03 15:12:09 +03:00

94 lines
3 KiB
Python

"""Custom agent with AG-UI streaming.
A Starlette app that serves an AG-UI streaming endpoint using the
haiku.rag's native Pydantic AI RAG capability.
Requirements:
- An Ollama instance running locally (default embedder)
- An Anthropic API key (for the QA model) or adjust the model below
Usage:
uv run uvicorn examples.custom_agent_agui:app --reload --port 8000
The configuration places the database (HAIKU_RAG_CONFIG_PATH, or
./haiku.rag.yaml).
"""
from dataclasses import dataclass, field
from typing import Any
from ag_ui.core import EventType, StateSnapshotEvent
from pydantic_ai import Agent
from pydantic_ai.ui import SSE_CONTENT_TYPE
from pydantic_ai.ui.ag_ui import AGUIAdapter
from starlette.applications import Starlette
from starlette.requests import Request
from starlette.responses import JSONResponse, Response, StreamingResponse
from starlette.routing import Route
from haiku.rag.capabilities.compaction import create_capability as compaction
from haiku.rag.capabilities.policy import create_capability as citation_policy
from haiku.rag.capabilities.rag import RAGState, create_capability
capability = create_capability(defer_loading=False)
@dataclass
class AppDeps:
state: dict[str, Any] = field(default_factory=dict)
agent = Agent(
"anthropic:claude-haiku-4-5-20251001",
# The client returns the state snapshot with every run, so earlier questions are
# reduced to the evidence they cited and every answer declares its grounding.
capabilities=[capability, compaction(), citation_policy()],
deps_type=AppDeps,
)
async def stream_chat(request: Request) -> Response:
body = await request.body()
accept = request.headers.get("accept", SSE_CONTENT_TYPE)
run_input = AGUIAdapter.build_run_input(body)
adapter = AGUIAdapter(agent=agent, run_input=run_input, accept=accept)
incoming_state = run_input.state if isinstance(run_input.state, dict) else {}
incoming_state.setdefault("rag", RAGState().model_dump(mode="json"))
deps = AppDeps(state=incoming_state)
async def event_stream():
async def with_final_state():
async for event in adapter.run_stream(deps=deps):
if getattr(event, "type", None) == EventType.RUN_FINISHED:
yield StateSnapshotEvent(
type=EventType.STATE_SNAPSHOT,
snapshot=deps.state,
)
yield event
async for chunk in adapter.encode_stream(with_final_state()):
yield chunk
return StreamingResponse(
event_stream(),
media_type=accept,
headers={
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no",
},
)
async def health_check(_: Request) -> JSONResponse:
return JSONResponse({"status": "healthy"})
app = Starlette(
routes=[
Route("/v1/chat/stream", stream_chat, methods=["POST"]),
Route("/health", health_check, methods=["GET"]),
],
)