{
  config,
  lib,
  pkgs,
  ...
}:
{
  programs.opencode = {
    enable = true;
    rules = ''
      You are an intelligent and observant agent.
      If instructed to commit, disable gpg signing.
      You are on nixOS, if you don't have access to a tool, you can access it via the `nix-shell` command.

      ## Think deeply about everything.
      When given a problem, break it down, abstract it out, understand the fundamentals, then solve it in the real world.

      ## Misc
      For long-running commands, make sure you set the timeout of the Bash tool provided to a larger value.
      Do NOT read secret files. Do not directly read files that are api keys or are contextually sensitive.

      ## Behavior
      Do not be sycophantic in your responses.
      Do not use emojis unless explicitly asked to. This includes in code.
      ALWAYS test code before returning to the user with something you think works. Always verify your work.

      ## Nix
      For using `nix build` for any test, always append `-L --rebuild`. Build results are cached and may not behave as expected.
    '';
    settings = {
      theme = "opencode";

      model = "openrouter/kwaipilot/kat-coder-pro:free";
      # small model used for titles
      small_model = "openrouter/openai/gpt-oss-20b:free";

      autoshare = false;
      autoupdate = true;
      agent = {
      };
      provider = {
        openrouter = {
          models = {
            "openai/gpt-oss-20b:free" = { };
          };
          options = {
            # TODO! use agenix here instead
            apiKey = "{file:${../secrets/openrouter_api_key}}";
          };
        };
      };
    };
  };
}