AI Configuration

All AI tooling is configured declaratively in Nix and deployed via decknix switch.

Auggie CLI

Enabling

{ ... }: {
  decknix.cli.auggie.enable = true;
}

Settings

{ ... }: {
  decknix.cli.auggie.settings = {
    model = "opus4.6";
    indexingAllowDirs = [
      "~/tools/decknix"
      "~/Code"
    ];
  };
}

Settings are written to ~/.augment/settings.json. The file is copied (not symlinked) so auggie can modify it at runtime; the next decknix switch overwrites with the Nix-managed version.

MCP Servers

Declaratively configure Model Context Protocol servers:

{ ... }: {
  decknix.cli.auggie.mcpServers = {
    context7 = {
      type = "stdio";
      command = "npx";
      args = [ "-y" "@upstash/context7-mcp@latest" ];
      env = {};
    };
    "gcp-monitoring" = {
      type = "stdio";
      command = "npx";
      args = [ "-y" "gcp-monitoring-mcp" ];
      env.GOOGLE_APPLICATION_CREDENTIALS = "~/.config/gcloud/credentials.json";
    };
  };
}

MCP servers are written into the mcpServers section of ~/.augment/settings.json.

Slack MCP Workspaces

Connect auggie to one or more Slack workspaces using the official Slack MCP server:

{ ... }: {
  decknix.cli.auggie.slack.workspaces = {
    acme-corp = {
      clientId = "3660753192626.123456";
      description = "ACME Corp team workspace";
    };
    personal = {
      clientId = "3660753192626.789012";
    };
  };
}

Each workspace generates a slack-<name> entry in mcpServers pointing at https://mcp.slack.com/mcp with the workspace's CLIENT_ID for OAuth authentication.

Setup requirements:

Create or reuse a Slack app at api.slack.com/apps
Enable OAuth with appropriate scopes (e.g., search:read.public, chat:write, channels:history)
Publish as an internal app or to the Slack Marketplace
Copy the Client ID from the app's OAuth settings

Multiple workspaces merge naturally — define some in your org config, others in your personal config, and they all appear in settings.json.

Viewing Configured Servers

From Emacs: C-c A S opens a formatted buffer showing all configured MCP servers with their type, command, args, and environment variables.

Runtime vs Nix-Managed

Source	Persists across `decknix switch`?	How to add
Nix config	✅ Yes	`decknix.cli.auggie.mcpServers`
`auggie mcp add`	❌ No (temporary)	Runtime command

Agent Shell Module

The Emacs agent-shell module is enabled by default in the full profile:

{ ... }: {
  programs.emacs.decknix.agentShell = {
    enable = true;           # Core agent-shell.el + ACP
    manager.enable = true;   # Tabulated session dashboard
    workspace.enable = true; # Dedicated tab-bar workspace
    attention.enable = true; # Mode-line attention tracker
    templates.enable = true; # Yasnippet prompt templates
    commands.enable = true;  # Nix-managed slash commands
    context.enable = true;   # Work context panel (issues, PRs, CI)
  };
}

Each sub-module can be independently disabled. See Agent Shell Overview for details on each component.

Custom Commands

Nix-managed commands are deployed to ~/.augment/commands/ as symlinks. User-created commands (regular files) coexist in the same directory and are not affected by decknix switch.

# Commands are defined in agent-shell.nix and deployed automatically.
# To add your own at runtime:
# C-c c n  → Create new command (opens template in ~/.augment/commands/)

See Productivity for the full command framework.

Decknix Documentation