go-ai-agent

This repo contains the code for Thorsten Ball's "How to Build an Agent" post (see here).

Setup

This repo contains everything you need to get a development environment ready to go through the tutorial. You'll first need to make sure nix and direnv are installed. An anthropic API key is also required (one can be generated here).

Install Nix

Nix is package manager that allows us to "make reproducible, declarative and reliable systems" (according to their site).

Nix can be installed using the Determinate Systems installer. Run the following command:

curl -fsSL https://install.determinate.systems/nix | sh -s -- install --determinate

Install Direnv

Direnv is a tool that enables us to quickly load and unload an environemnt when we enter and leave a directory.

Direnv is available in homebrew. Run the following command:

brew install direnv

Once it's installed you'll have to configure your shell. If you're using ZSH run the following:

echo 'eval "$(direnv hook bash)"' >> ~/.zshrc

NOTE: You'll have to start a new terminal session for the changes in ~/.zshrc to take effect!

For all other shells, refer here.

Configure Anthropic API Key

First, generate an Anthropic API key from the console. This repo has a .envrc (direnv configuration file) that will read from a .env file (not committed to this repo since we'll use it to house secrets). Once you have your API key, run the following (make sure to replace the placeholder text with your actual API key):

echo 'export ANTHROPIC_API_KEY=<your generated key>' > .env

Build the Development Environment

We're now ready to build the development environment. Direnv configuration files (.envrc files) have to be explicitly trusted before they take effect. Run the following to build and automatically enter the development environment:

direnv allow

Once that runs, nix will do its thing and set up the environment. This might take a bit. Once it's done you can check to see if it worked by running the following:

which go

This should spit out a value like /nix/store/fd2s1z3why92qn8w7j6r0xlarikpv27v-go-1.24.2/bin/go.

Follow the Tutorial

You can now follow the tutorial. This repo also has some branches containing the tutorial code as well if you'd prefer to not copy/paste (or preferably type it out) yourself. Branches step1, step2, step3, step4 correspond to the different parts of the tutorial. step1 is the initial setup of the conversation loop and the other steps correspond to the three tools you'll implement as part of the tutorial.