Fast Agent - EvalState

Fast Agent

EvalState · Terminal & CLI Agents · Updated Aug 12, 2026

Fast Agent is an open-source Python framework designed for building, testing, and running MCP-compliant AI agents and workflows. It prioritizes a declarative, file-centric approach to agent orchestration, enabling rapid development of complex multi-agent systems.

Recent Updates

Recent versions (v0.9.x) have added first-party provider support for ZAI, DeepSeek, and Moonshot, along with container/sandbox isolation, expanded model presets like GPT-5.6 and Grok 4.5, and improvements to terminal rendering and background process handling.

As of Aug 12, 2026

Key Features

Complete Model Context Protocol (MCP) support including Sampling and Elicitations
Prebuilt workflow patterns like Chain, Parallel, Router, Orchestrator, and MAKER
Multimodal support for text, images, PDFs, and video
Interactive CLI-first runtime with TUI and real-time debugging
Comprehensive provider support including Anthropic, OpenAI, Google, and local models

Who It's For

✓ Best For

Rapid prototyping of complex multi-agent workflows, building MCP-compliant services, and engineering scenarios requiring strict version control of prompts and agent configurations.

✗ Not Ideal For

Users who prefer heavy GUI-based visual builders or those looking for a non-programmatic, zero-code environment.

Pricing

Open Source

Released under the Apache License 2.0.

Verdict

Fast Agent is a powerful, standards-aligned choice for developers who want a robust, MCP-first foundation for agent orchestration that excels in both rapid experimentation and production-ready deployments.