Alternatives to fast-agent

4 editor-selected alternatives · fast-agent overview →

source: tools.alternatives · stored order · active records only; review scores are annotations and never change membership or order

A directional evidence panel appears only when the substitute rationale, trade-offs, sources, and verification date have been recorded. Older selections without that panel remain visible but are unclassified under the new evidence contract.

mcp-agent

open sourceexplicit relation

mcp-agent is an open-source framework with 8K+ GitHub stars for building AI agents that leverage MCP (Model Context Protocol) servers as composable tool providers. Agents connect to multiple MCP servers simultaneously, gaining access to diverse capabilities without custom integrations. Supports multi-agent workflows, parallel tool execution, and automatic server discovery. Designed to make MCP the universal interface between AI agents and external tools, databases, and services.

Free and 100% open source under the Apache-2.0 license. mcp-agent has no subscription tiers, seat limits, or licensing fees; developers can build, run, and self-host MCP-native AI agents locally or deploy them to cloud infrastructure with Temporal durability.

SmoLAgents

open sourceexplicit relation

smolagents is Hugging Face's lightweight agent framework for building AI agents that can use tools, write and execute code, and collaborate in multi-agent setups. Designed for simplicity with minimal abstractions — agents are just LLMs that write Python code to orchestrate tool calls rather than using JSON-based function calling. Supports any LLM provider, integrates with Hugging Face Hub for sharing tools and agents, and runs with as few as 1,000 lines of core library code.

smolagents is Hugging Face's lightweight, open-source library for building code-centric AI agents. It is 100% free under the Apache 2.0 license, using standard Hugging Face Inference or local model endpoints.

Agno

82/100open sourceexplicit relation

Fast, lightweight Python framework for building multi-modal AI agents, formerly known as Phidata. Includes built-in memory, knowledge bases, tools, and reasoning capabilities with 40K+ GitHub stars. Designed for developers who want to build production-ready agents quickly with minimal boilerplate, supporting structured outputs and multi-agent coordination out of the box.

Agno (formerly Phidata) offers a free open-source framework under the MIT license for building multimodal AI agents. The managed production platform provides a Pro plan at $150/month (including 1 live connection) and custom Enterprise tiers.Review →

Pydantic AI

85/100open sourceexplicit relation

Agent framework built on Pydantic for type-safe AI applications. Provides structured outputs, dependency injection, and multi-model support. Created by the Pydantic team, it brings the same validation and typing philosophy that made Pydantic essential for Python APIs to the world of AI agents, ensuring reliable data flow between LLMs and application logic.

PydanticAI is an open-source, production-grade agent framework developed by the Pydantic team under the MIT license. It is free to use with zero licensing costs, requiring only BYOK model API keys or local LLM runtimes.Review →

Open-source fast-agent alternatives

mcp-agent, SmoLAgents, Agno, Pydantic AI — see all open-source developer tools.

More Agent Frameworks tools

same category, not editor-selected alternatives — see how fast-agent compares →

Grok BotGrok Bot is SpaceXAI's beta workspace for persistent AI teammates that use apps, websites, files, terminals, plugins, and MCP on a user-scoped cloud computer. Bots can learn routines, coordinate in parallel, and, when enabled by team policy, launch Cursor Cloud Agents that work on code in isolated environments and return pull requests and verification artifacts.LatitudeLatitude is an agent observability platform for teams that need to inspect LLM traces, conversations, issues, and evaluation feedback in one workflow. Its public repo and docs position it as a Sentry-style monitor for AI agents, with semantic search, issue detection, annotations, MCP-assisted fixes, and cloud or self-hosted deployment paths for production debugging.JudgevalJudgeval is the open-source post-building layer for AI agents from Judgment Labs, providing OpenTelemetry-based tracing, hosted and custom evaluation scorers, and online behavior monitoring for LLM-powered applications. Instrument any function with a single decorator, score live production traffic against faithfulness and instruction-adherence checks, and feed real-world failures back into reinforcement learning or supervised fine-tuning loops.Mem0Mem0 is an open-source intelligent memory layer for AI agents with 51K+ GitHub stars providing persistent, adaptive memory across sessions. It manages working, short-term, and long-term memory types, enabling personalized AI experiences that improve over time. Features automatic memory extraction from conversations, semantic search over stored memories, multi-format support, and integration with 100+ frameworks. Simple API for adding memory to any LLM-powered application or agent.chrome-devtools-mcpchrome-devtools-mcp is the Chrome DevTools team's official MCP server that lets coding agents control and inspect a live Chrome browser with first-party Chrome DevTools Protocol fidelity. It exposes Network inspection, Performance traces, Lighthouse audits, console output, and structured DOM snapshots as typed MCP tools, so agents can debug real pages and ship reliable web performance investigations without resorting to brittle DOM scraping.E2BE2B provides secure cloud sandboxes that let AI agents execute code, run terminal commands, and interact with filesystems in isolated environments. Each sandbox spins up in ~150ms with its own OS, giving agents a safe space to run untrusted code. Supports Python, JavaScript, and any language via custom Dockerfiles. Used by AI coding assistants, data analysis agents, and code interpreters. SDK available for Python and JavaScript with a simple API for programmatic sandbox control.LlamaIndexLeading Python framework for building LLM-powered applications with focus on data-aware and agentic workflows. Provides tools for RAG (Retrieval-Augmented Generation), document indexing, vector store integrations, query engines, and multi-agent orchestration. 150+ data connectors for various sources. Works with OpenAI, Anthropic, local models, and more. Includes LlamaHub for community tools and LlamaCloud for managed RAG pipelines. 50K+ GitHub stars.OpenWikiOpenWiki is LangChain’s open-source CLI for generating and maintaining an agent-focused wiki inside a codebase. It can create an openwiki/ documentation folder, update it from repository changes, add guidance to AGENTS.md or CLAUDE.md, and run via an interactive CLI or daily GitHub Action so coding agents have durable context without stuffing every detail into prompts.SupermemorySupermemory is a memory and context platform for AI assistants and agents. It ranks #1 on LongMemEval, LoCoMo, and ConvoMem, supports MCP for Claude/Cursor-style clients, provides plugins for developer tools, and combines memory extraction, user profiles, hybrid search, connectors, and RAG in one API.

FAQ

Which fast-agent alternative is listed first?

mcp-agent is first in the editor-selected list of 4 fast-agent alternatives. The stored order is editorial; review scores do not determine membership or position.

Are there open-source fast-agent alternatives?

Yes — mcp-agent, SmoLAgents, Agno, and more are open source.