nixpkgs/modules/home-manager/coding/agents/claude-code.nix

{
  config,
  lib,
  pkgs,
  ...
}: let
  shared = import ./shared-options.nix {inherit lib;};
in
  with lib; let
    cfg = config.coding.agents.claude-code;
    mcpCfg = config.programs.mcp or null;
  in {
    options.coding.agents.claude-code = {
      enable = mkEnableOption "Claude Code agent management via canonical agent.toml definitions";

      agentsInput = shared.mkAgentsInputOption ''
        The `agents` flake input (your personal AGENTS repo).
        When set, agents are rendered from canonical agent.toml files
        and symlinked to ~/.claude/agents/.
      '';

      modelOverrides = shared.mkModelOverridesOption;

      externalSkills = shared.externalSkillsOption;

      mcpServers = mkOption {
        type = types.attrsOf types.anything;
        default =
          if mcpCfg != null
          then mcpCfg.servers
          else {};
        defaultText = literalExpression "config.programs.mcp.servers";
        description = ''
          MCP server configurations for Claude Code.
          Merged into ~/.claude/settings.json alongside permissions.
          Automatically inherits from config.programs.mcp.servers.
        '';
      };
    };

    config = mkIf cfg.enable (let
      agentsLib = (import ../../../../lib {inherit lib;}).agents;

      # Rendered agents + permissions (only if agentsInput is set)
      rendered = mkIf (cfg.agentsInput != null) (
        agentsLib.renderForClaudeCode {
          inherit pkgs;
          canonical = cfg.agentsInput.lib.loadAgents;
          modelOverrides = cfg.modelOverrides;
        }
      );

      # Merge MCP servers into the rendered settings.json.
      # The renderer produces { permissions: { allow, deny } }.
      # We add mcpServers on top.
      settingsJson =
        if cfg.agentsInput != null
        then let
          renderedSettings = builtins.fromJSON (builtins.readFile "${rendered}/.claude/settings.json");
          withMcp =
            if cfg.mcpServers != {}
            then renderedSettings // {mcpServers = cfg.mcpServers;}
            else renderedSettings;
        in
          pkgs.writeText "claude-settings.json" (builtins.toJSON withMcp)
        else if cfg.mcpServers != {}
        then pkgs.writeText "claude-settings.json" (builtins.toJSON {mcpServers = cfg.mcpServers;})
        else null;
    in {
      # Rendered agent files symlinked to ~/.claude/agents/
      home.file.".claude/agents" = mkIf (cfg.agentsInput != null) {
        source = "${rendered}/.claude/agents";
      };

      # Skills (merged from personal AGENTS repo + optional external skills)
      home.file.".claude/skills" = mkIf (cfg.agentsInput != null) {
        source = cfg.agentsInput.lib.mkOpencodeSkills {
          inherit pkgs;
          customSkills = "${cfg.agentsInput}/skills";
          externalSkills = shared.mapExternalSkills cfg.externalSkills;
        };
      };

      # Rendered settings.json with permissions + MCP servers
      home.file.".claude/settings.json" = mkIf (settingsJson != null) {
        source = "${settingsJson}";
      };
    });
  }