{
  config,
  lib,
  pkgs,
  trollshell,
  ...
}:
let
  trollshellPkgs = trollshell.packages.${pkgs.stdenv.hostPlatform.system};

  # The claude bridge's loopback port, shared between the daemon and the pet
  # that talks to it so there is one number to change. The address is fixed at
  # 127.0.0.1 by the bridge and is not configurable: the bridge validates no
  # bearer token at all, so reachability *is* the authorization boundary.
  bridgePort = 8787;
in
{
  programs.trollshell = {
    enable = true;
    weather.fallbackCity = "Berlin";
    cliphist.enable = true;
    stats.layout = "split";
    plugins = {
      pet = {
        enable = true;
        package = trollshellPkgs.hytte-plugin-pet;
        env = {
          PET_NAME = "foo";
          PET_LLM_URL = "http://127.0.0.1:${toString bridgePort}";
          # Not a real key. `hytte_ai_providers::load_key` checks this env
          # override *before* ~/.config/trollshell/openrouter.key, so this dummy
          # is what stops a genuine OpenRouter key being shipped to a loopback
          # port. It is a security control, not a placeholder — don't drop it.
          OPENROUTER_API_KEY = "local-bridge";
          PET_LLM_MIN_GAP_SECS = "1";
          PET_LLM_TIMEOUT_SECS = "30";
          PET_PERSONA = "cheerful, impatient and easily excitable";
        };
      };
      departures = {
        enable = true;
        package = trollshellPkgs.hytte-plugin-departures;
      };
      usage = {
        enable = true;
        package = trollshellPkgs.hytte-plugin-usage;
      };
      weather = {
        enable = true;
        package = trollshellPkgs.hytte-plugin-weather;
      };
    };
  };

  # The keyless loopback shim that puts an OpenAI-compatible face on headless
  # `claude --print`, so pet rides the Claude Code subscription instead of
  # OpenRouter. trollshell ships the package and a reference unit under `etc/`
  # but no module option for it, so the unit is declared here — without it the
  # pet's PET_LLM_URL above points at nothing and the plugin stays canned-only.
  systemd.user.services.trollshell-claude-bridge = {
    Unit = {
      Description = "Keyless loopback OpenAI-compatible bridge to headless Claude Code";
      PartOf = [ config.programs.trollshell.systemd.target ];
      After = [ config.programs.trollshell.systemd.target ];
    };

    Service = {
      Type = "simple";
      ExecStart = lib.getExe trollshellPkgs.hytte-claude-bridge;
      Restart = "on-failure";
      RestartSec = 5;

      Environment = [
        "RUST_LOG=hytte_claude_bridge=info"
        "CLAUDE_BRIDGE_PORT=${toString bridgePort}"
        # `claude --model` for the child. Worth pinning: the bridge's default
        # per-request budget is 8s (it must stay under the client's 10s), and
        # the child otherwise inherits the model from ~/.claude/settings.json —
        # currently opus, which would blow that budget on nearly every reply.
        "CLAUDE_BRIDGE_MODEL=claude-haiku-4-5"
        "CLAUDE_BRIDGE_TIMEOUT_SECS=25"
        # Belt-and-braces; the copy that actually prevents a leak is the one on
        # the pet above, because load_key runs in the plugin's process.
        "OPENROUTER_API_KEY=local-bridge"
        # The bridge shells out to `claude`, which is the OTEL wrapper from
        # ./claude.nix — so pet chatter is counted as workstation usage.
        "PATH=${config.home.profileDirectory}/bin:/run/current-system/sw/bin"
      ];

      # SECURITY CONTROL — do not drop. These four would silently move `claude`
      # off the subscription and onto metered API credits (or Bedrock/Vertex).
      # The bridge cannot scrub them itself (`std::env::remove_var` is unsafe
      # under edition 2024 and that workspace forbids unsafe), so it fails
      # closed instead: it *refuses to start* if it finds any of them set.
      UnsetEnvironment = "ANTHROPIC_API_KEY ANTHROPIC_AUTH_TOKEN CLAUDE_CODE_USE_BEDROCK CLAUDE_CODE_USE_VERTEX";
    };

    Install.WantedBy = [ config.programs.trollshell.systemd.target ];
  };
}