Tools

Arcana gives agents scoped access to shell, filesystem, git, and external Model Context Protocol (MCP) tools. Tool access is part of the session runtime and should remain bounded by the workspace and the active permission profile.

Built-in tools

Built-in capabilities cover common agent work such as reading files, editing files, running commands, inspecting repositories, and interacting with git. Arcana keeps these actions visible in the session timeline and applies the configured permission policy before execution.

MCP servers

MCP extends Arcana with external tools and data sources. Servers can be remote HTTP endpoints or local subprocesses.

# Add a remote MCP server
arcana mcp add my-tools --url http://localhost:3001

# List configured servers
arcana mcp list

# Authenticate an OAuth-enabled server
arcana mcp auth my-tools

# Debug a connection
arcana mcp debug my-tools

Configuration

MCP servers are configured under the mcp key in ~/.config/arcana/arcana.json.

{
  "mcp": {
    "filesystem": {
      "type": "local",
      "command": ["npx", "-y", "@modelcontextprotocol/server-filesystem", "."]
    },
    "my-api": {
      "type": "remote",
      "url": "https://mcp.example.com",
      "headers": {
        "Authorization": "Bearer sk-..."
      }
    }
  }
}

Security model

Connecting a tool does not mean every tool call should execute automatically. Workspace trust, tool permissions, and approvals remain separate controls. Treat remote MCP servers as external capabilities and scope credentials to the minimum required access.

Full MCP reference

The detailed MCP setup, OAuth, flags, and command reference remains available at MCP & Tools reference.