🦜️🔗 LangChain-mini

This is a very simple re-implementation of LangChain, in ~100 lines of code. In essence, it is an LLM (GPT-3.5) powered chat application that is able to use tools (Google search and a calculator) in order to hold conversations and answer questions.

Here's an example:

Q: What is the world record for solving a rubiks cube?
The world record for solving a Rubik's Cube is 4.69 seconds, held by Yiheng Wang (China).
Q: Can a robot solve it faster?
The fastest time a robot has solved a Rubik's Cube is 0.637 seconds.
Q: Who made this robot?
Infineon created the robot that solved a Rubik's Cube in 0.637 seconds.
Q: What time would an average human expect for solving?
It takes the average person about three hours to solve a Rubik's cube for the first time.

This is not intended to be a replacement for LangChain, instead it was built for fun and educational purposes. If you're interested in how LangChain, and similar tools work, this is a good starting point.

For more information about this project, read the accompanying blogpost - Re-implementing LangChain in 100 lines of code

Running / developing

Install dependencies, and run (with node >= v18):

% npm install

You'll need to have both an OpenAI and SerpApi keys. These can be supplied to the application via a .env file:

OPENAI_API_KEY="..."
SERPAPI_API_KEY="..."

You can now run the chain:

% node index.mjs
How can I help? what was the name of the first man on the moon?
Neil Armstrong