Skip to main content

​
Introduction

fast-agent is CLI-first, providing a comprehensive command-line interface for creating, managing, and running AI agents. The CLI enables rapid development and testing without requiring a GUI or external dependencies.

​
Quick Start

# Start an interactive agent session
fast-agent go

# Create agent template and configuration files
fast-agent scaffold

# Create workflow examples
fast-agent quickstart workflow

# Check configuration and setup
fast-agent check

​
Available Commands

fast-agent provides the following primary commands:

go

Start an interactive agent session directly from the command line

scaffold

Create agent template and configuration files for new projects

quickstart

Generate example applications and workflow patterns

auth

Manage OAuth tokens for MCP servers in the OS keyring

​
Additional Commands

  • serve - Start fast-agent as an MCP server
  • acp - Start fast-agent as an ACP server (Agent Communication Protocol)
  • check - Show current configuration and verify API keys
  • cards - Manage card packs (list/add/remove/update/publish)
  • config - Configure settings interactively (shell, model)
  • demo - Run local UI demos without making model calls

​
Command Structure

All commands follow a consistent pattern: 
fast-agent <command> [arguments] [options]

​
Common Options

These options are available across multiple commands:
OptionShortDescription
--config-path-cPath to config file
--modelOverride the default model (e.g., haiku, sonnet, gpt-4)
--envOverride the base fast-agent environment directory
--noenvRun without implicit environment-side effects
--verbose-vEnable verbose mode
--quiet-qDisable output
--help-hShow help for the command

​
Global Flags

The following flags are available for the main fast-agent command: 
fast-agent --version              # Show version and exit
fast-agent --color/--no-color     # Enable/disable color output
fast-agent --help                 # Show help message

​
Getting Help

Every command supports the --help flag to show detailed usage information: 
fast-agent --help           # Show all commands
fast-agent go --help        # Show help for 'go' command
fast-agent auth --help      # Show help for 'auth' command

​
Configuration Files

fast-agent uses YAML configuration files:
  • fastagent.config.yaml - Main configuration for agents and MCP servers
  • fastagent.secrets.yaml - Secure storage for API keys and secrets
These files are automatically searched for recursively from the current directory upward.
fast-agent will look recursively for configuration files, so you only need to manage them at the root folder of your agent definitions.

​
Interactive Features

The CLI includes an optional prompt_toolkit-powered interactive terminal prompt with:
  • TUI-style input with completions
  • In-terminal menus for agent switching
  • Live streaming responses via rich formatting
  • Slash commands for special operations

​
Next Steps

go Command

Learn about starting interactive sessions

scaffold Command

Create your first agent project

Configuration

Configure agents and MCP servers

Quickstart Examples

Explore workflow patterns and examples

Build docs developers (and LLMs) love

Get started for freeTalk to us