kirche-einfach/backend/app/flows/langflow_client.py
Jonas Miederer 1034206870 feat: Langflow authoring pipeline with tests
- LangflowClient (list/export, x-api-key auth, error mapping)
- import_from_langflow: export -> versioned definition -> LFX deploy
- POST /api/flows/import, GET /api/flows/langflow/available
- scripts/deploy_flow.py CLI
- 25 tests green (Langflow faked via dependency override + respx
  client tests; respx passthrough proven unreliable for LFX traffic)
2026-09-06 23:01:47 +00:00

66 lines
2.5 KiB
Python

"""Async client for the Langflow authoring server (visual designer).
Only used for the authoring pipeline (list/export flows). Execution always
goes through LFX (see lfx_client.py).
"""
from __future__ import annotations
import httpx
class LangflowError(Exception):
pass
class LangflowNotFound(LangflowError):
pass
class LangflowUnavailable(LangflowError):
pass
class LangflowClient:
"""Thin async wrapper around the Langflow `/api/v1/flows` endpoints."""
def __init__(self, base_url: str, api_key: str = "", timeout: float = 60.0) -> None:
self.base_url = base_url.rstrip("/")
self.api_key = api_key
self.timeout = timeout
def _headers(self) -> dict[str, str]:
return {"x-api-key": self.api_key} if self.api_key else {}
async def list_flows(self) -> list[dict]:
"""List flows (header mode keeps payloads small)."""
try:
async with httpx.AsyncClient(
base_url=self.base_url, timeout=self.timeout, headers=self._headers()
) as client:
response = await client.get("/api/v1/flows/", params={"header_flows": "true"})
if response.status_code == 404:
raise LangflowNotFound("flow list not found")
response.raise_for_status()
data = response.json()
return data if isinstance(data, list) else data.get("items", [])
except httpx.HTTPStatusError as exc:
raise LangflowError(f"Langflow error {exc.response.status_code}") from exc
except httpx.HTTPError as exc:
raise LangflowUnavailable(f"Langflow unreachable: {exc}") from exc
async def export_flow(self, langflow_flow_id: str) -> dict:
"""Export one flow as Langflow JSON (FlowRead: id/name/description/data)."""
try:
async with httpx.AsyncClient(
base_url=self.base_url, timeout=self.timeout, headers=self._headers()
) as client:
response = await client.get(f"/api/v1/flows/{langflow_flow_id}")
if response.status_code == 404:
raise LangflowNotFound(f"flow {langflow_flow_id} not found")
response.raise_for_status()
return response.json()
except httpx.HTTPStatusError as exc:
raise LangflowError(f"Langflow error {exc.response.status_code}") from exc
except httpx.HTTPError as exc:
raise LangflowUnavailable(f"Langflow unreachable: {exc}") from exc