cli updates oct27 (#12436)

libs/cli/langchain_cli/cli.py

@@ -1,4 +1,3 @@
-import subprocess
 from typing import Optional
 
 import typer
@@ -24,12 +23,12 @@ def start(
     """
     Start the LangServe instance, whether it's a hub package or a serve project.
     """
-    cmd = ["poetry", "run", "poe", "start"]
-    if port is not None:
-        cmd += ["--port", str(port)]
-    if host is not None:
-        cmd += ["--host", host]
-    subprocess.run(cmd)
+
+    # try starting hub package, if error, try langserve
+    try:
+        hub.start(port=port, host=host)
+    except KeyError:
+        serve.start(port=port, host=host)
 
 
 if __name__ == "__main__":

libs/cli/langchain_cli/namespaces/hub.py

@@ -9,8 +9,11 @@ from pathlib import Path
 from typing import Optional
 
 import typer
+from langserve.packages import get_langserve_export
 from typing_extensions import Annotated
 
+from langchain_cli.utils.packages import get_package_root
+
 hub = typer.Typer(no_args_is_help=True, add_completion=False)
 
 
@@ -19,9 +22,7 @@ def new(
     name: Annotated[str, typer.Argument(help="The name of the folder to create")],
     with_poetry: Annotated[
         bool,
-        typer.Option(
-            "--with-poetry/--no-poetry", help="Don't run poetry install"
-        ),
+        typer.Option("--with-poetry/--no-poetry", help="Don't run poetry install"),
     ] = False,
 ):
     """
@@ -82,9 +83,23 @@ def start(
     """
     Starts a demo LangServe instance for this hub package.
     """
-    cmd = ["poetry", "run", "poe", "start"]
-    if port is not None:
-        cmd += ["--port", str(port)]
-    if host is not None:
-        cmd += ["--host", host]
-    subprocess.run(cmd)
+    # load pyproject.toml
+    project_dir = get_package_root()
+    pyproject = project_dir / "pyproject.toml"
+
+    # get langserve export - throws KeyError if invalid
+    get_langserve_export(pyproject)
+
+    port_str = str(port) if port is not None else "8000"
+    host_str = host if host is not None else "127.0.0.1"
+
+    command = [
+        "uvicorn",
+        "langchain_cli.dev_scripts:create_demo_server",
+        "--reload",
+        "--port",
+        port_str,
+        "--host",
+        host_str,
+    ]
+    subprocess.run(command)

libs/cli/langchain_cli/namespaces/serve.py

@@ -218,13 +218,15 @@ def start(
     host: Annotated[
         Optional[str], typer.Option(help="The host to run the server on")
     ] = None,
+    app: Annotated[Optional[str], typer.Option(help="The app to run")] = None,
 ) -> None:
     """
     Starts the LangServe instance.
     """
-    cmd = ["poetry", "run", "poe", "start"]
-    if port is not None:
-        cmd += ["--port", str(port)]
-    if host is not None:
-        cmd += ["--host", host]
+
+    app_str = app if app is not None else "app.server:app"
+    port_str = str(port) if port is not None else "8000"
+    host_str = host if host is not None else "127.0.0.1"
+
+    cmd = ["uvicorn", app_str, "--reload", "--port", port_str, "--host", host_str]
     subprocess.run(cmd)

libs/cli/langchain_cli/package_template/pyproject.toml

@@ -11,7 +11,6 @@ langchain = ">=0.0.313, <0.1"
 openai = "^0.28.1"
 
 [tool.poetry.group.dev.dependencies]
-poethepoet = "^0.24.1"
 langchain-cli = ">=0.0.4"
 fastapi = "^0.104.0"
 sse-starlette = "^1.6.5"
@@ -20,13 +19,6 @@ sse-starlette = "^1.6.5"
 export_module = "__package_name__.chain"
 export_attr = "chain"
 
-[tool.poe.tasks.start]
-cmd="uvicorn langchain_cli.dev_scripts:create_demo_server --reload --port $port --host $host"
-args = [
-    {name = "port", help = "port to run on", default = "8000"},
-    {name = "host", help = "host to run on", default = "127.0.0.1"}
-]
-
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"

libs/cli/langchain_cli/project_template/app/server.py

@@ -9,4 +9,4 @@ add_routes(app, NotImplemented)
 if __name__ == "__main__":
     import uvicorn
 
-    uvicorn.run(app, host="0.0.0.0", port=8001)
+    uvicorn.run(app, host="0.0.0.0", port=8000)

libs/cli/langchain_cli/project_template/pyproject.toml

@@ -14,17 +14,9 @@ fastapi = "^0.103.2"
 langserve = ">=0.0.16"
 
 [tool.poetry.group.dev.dependencies]
-poethepoet = "^0.24.1"
 uvicorn = "^0.23.2"
 pygithub = "^2.1.1"
 
-[tool.poe.tasks.start]
-cmd="uvicorn app.server:app --reload --port $port --host $host"
-args = [
-    {name = "port", help = "port to run on", default = "8000"},
-    {name = "host", help = "host to run on", default = "127.0.0.1"}
-]
-
 
 [build-system]
 requires = ["poetry-core"]

libs/cli/pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "langchain-cli"
-version = "0.0.5"
+version = "0.0.6"
 description = "CLI for interacting with LangChain"
 authors = ["Erick Friis <erick@langchain.dev>"]
 readme = "README.md"

templates/README.md

@@ -2,6 +2,10 @@
 
 Templates for a fully functioning app that can be hosted by LangServe.
 
+Some other helpful docs:
+
+- [Templates]
+
 ## Usage
 
 To use, first install the LangChain CLI.
@@ -13,7 +17,7 @@ pip install -U langchain-cli
 Then, install `langserve`:
 
 ```shell
-pip install "langserve[all]"
+pip install -U "langserve[all]"
 ```
 
 Next, create a new LangChain project:
@@ -47,7 +51,7 @@ You then need to install this package so you can use it in the langserve app:
 pip install -e packages/$PROJECT_NAME
 ```
 
-We install it with `-e` so that if we modify the template at all (which we likely will) the changes are updated.
+We install it with `-e` so that if you modify the template at all (which you likely will) the changes are updated.
 
 In order to have LangServe use this project, you then need to modify `app/server.py`.
 Specifically, you should add something like:
@@ -66,7 +70,7 @@ add_routes(app, chain)
 You can then spin up production-ready endpoints, along with a playground, by running:
 
 ```shell
-python app/server.py
+langchain start
 ```
 
 ## Adding a template