Files
langchain/libs/cli/langchain_cli/dev_scripts.py
Christophe Bornet 20401df25d chore(cli): fix some DOC rules (preview) (#32839)
Co-authored-by: Mason Daugherty <mason@langchain.dev>
2025-09-08 14:36:22 +00:00

71 lines
1.9 KiB
Python

"""Development Scripts for template packages."""
from collections.abc import Sequence
from typing import Literal
from fastapi import FastAPI
from langserve import add_routes
from langchain_cli.utils.packages import get_langserve_export, get_package_root
def create_demo_server(
*,
config_keys: Sequence[str] = (),
playground_type: Literal["default", "chat"] = "default",
) -> FastAPI:
"""Create a demo server for the current template.
Args:
config_keys: Optional sequence of config keys to expose in the playground.
playground_type: The type of playground to use. Can be `'default'` or `'chat'`.
Returns:
The demo server.
Raises:
KeyError: If the `pyproject.toml` file is missing required fields.
ImportError: If the module defined in `pyproject.toml` cannot be imported.
"""
app = FastAPI()
package_root = get_package_root()
pyproject = package_root / "pyproject.toml"
try:
package = get_langserve_export(pyproject)
mod = __import__(package["module"], fromlist=[package["attr"]])
chain = getattr(mod, package["attr"])
add_routes(
app,
chain,
config_keys=config_keys,
playground_type=playground_type,
)
except KeyError as e:
msg = "Missing fields from pyproject.toml"
raise KeyError(msg) from e
except ImportError as e:
msg = "Could not import module defined in pyproject.toml"
raise ImportError(msg) from e
return app
def create_demo_server_configurable() -> FastAPI:
"""Create a configurable demo server.
Returns:
The configurable demo server.
"""
return create_demo_server(config_keys=["configurable"])
def create_demo_server_chat() -> FastAPI:
"""Create a chat demo server.
Returns:
The chat demo server.
"""
return create_demo_server(playground_type="chat")