langchain/templates/README.md

LangServe Hub

Packages that can be easily hosted by LangServe using the langserve cli.

Using LangServe Hub

You can install the langservehub CLI and use it as follows:

# install langservehub CLI
pip install --upgrade langservehub

langservehub new my-app
cd my-app

poetry install

# if you have problems with poe, use `poetry run poe ...` instead

# add the simple-pirate package
poe add --repo=pingpong-templates/hub simple-pirate

# adding other GitHub repo packages, defaults to repo root
poe add --repo=hwchase17/chain-of-verification

# with a custom api mount point (defaults to `/{package_name}`)
poe add --repo=pingpong-templates/hub simple-translator --api_path=/my/custom/path/translator

poe list

poe start
^C

# remove packages by their api path:
poe remove my/custom/path/translator

Creating New Packages

You can also create new packages with the langservehub package new command

# starting from this directory in langserve-hub
langservehub package new simple-newpackage

Now you can edit the chain in simple-newpackage/simple_newpackage/chain.py and put up a PR!

Your package will be usable as poe add --repo=pingpong-templates/hub simple-newpackage when it's merged in.

Data Format

What makes these packages work?

• Poetry
• pyproject.toml files

Installable Packages

Everything is a Poetry package currently. This allows poetry to manage our dependencies for us :).

In addition to normal keys in the pyproject.toml file, you'll notice an additional tool.langserve key (link).

This allows us to identify which module and attribute to import as the chain/runnable for the langserve add_routes call.

Apps (with installed langserve packages)

Let's say you add the pirate package with poe add --repo=pingpong-templates/hub simple-pirate.

First this downloads the simple-pirate package to pirate

Then this adds a poetry path dependency, which gets picked up from add_package_routes.