Best AI Tools for Building Agents (2026)
Frameworks, SDKs, and orchestration tools for building autonomous AI agents. From single-task bots to multi-agent systems — everything you need to ship production agents.
OpenAI Swarm — Lightweight Multi-Agent Orchestration
Educational multi-agent framework by OpenAI. Ergonomic agent handoffs, tool calling, and context variables. Minimal abstraction over Chat Completions API. 21K+ stars.
Anthropic Agent SDK — Build Production AI Agents
Official Anthropic SDK for building AI agents with tool use, memory, and orchestration. Production-grade agent framework with Claude as the backbone for autonomous tasks.
CrewAI — Multi-Agent Orchestration Framework
Python framework for orchestrating role-playing AI agents that collaborate on complex tasks. Define agents with roles, goals, and tools, then let them work together autonomously. 25,000+ stars.
mcp-agent — Build AI Agents with MCP Patterns
mcp-agent is a Python framework for building AI agents using the Model Context Protocol. 8.2K+ GitHub stars. Implements composable workflow patterns (orchestrator, map-reduce, evaluator-optimizer, rou
Haystack — AI Orchestration for Search & RAG
Open-source AI orchestration framework by deepset. Build production RAG pipelines, semantic search, and agent workflows with modular components. 25K+ GitHub stars.
CrewAI — Multi-Agent Orchestration Framework
Build teams of autonomous AI agents that collaborate on complex tasks. Define roles, assign tasks, and let crews work together.
CAMEL — Multi-Agent Framework at Scale
CAMEL is a multi-agent framework for studying scaling laws of AI agents. 16.6K+ GitHub stars. Up to 1M agents, RAG, memory systems, data generation. Apache 2.0.
LangGraph — Build Stateful AI Agents as Graphs
LangChain framework for building resilient, stateful AI agents as graphs. Supports cycles, branching, persistence, human-in-the-loop, and streaming. 28K+ stars.
DeepAgents — Multi-Step Agent Framework by LangChain
Agent harness built on LangGraph by the LangChain team. Features planning tools, filesystem backend, and sub-agent spawning for complex multi-step tasks like codebase refactoring. 16,500+ stars.
VoltAgent — TypeScript AI Agent Framework
Open-source TypeScript framework for building AI agents with built-in Memory, RAG, Guardrails, MCP, Voice, and Workflow support. Includes LLM observability console for debugging.
Camel AI — Multi-Agent Role-Playing Framework
Build multi-agent systems where AI agents collaborate through role-playing. CAMEL enables autonomous cooperation between agents with structured communication protocols.
oh-my-claudecode — Zero-Config Multi-Agent System
Zero learning curve multi-agent orchestration for Claude Code. Includes team mode, autopilot, Ralph persistent execution, and ultrawork parallel mode with 19 specialized agents.
DeepEval — LLM Testing Framework with 30+ Metrics
DeepEval is a pytest-like testing framework for LLM apps with 30+ metrics. 14.4K+ GitHub stars. RAG, agent, multimodal evaluation. Runs locally. MIT.
LangGraph — Stateful AI Agent Graphs by LangChain
Framework for building stateful, multi-actor AI agent applications as directed graphs. Supports cycles, branching, persistence, and human-in-the-loop patterns. By LangChain. 8,000+ stars.
Qwen-Agent — Build AI Agents on Qwen Models
Agent framework by Alibaba with function calling, code interpreter, RAG, and MCP support. Built for Qwen 3.0+. 15K+ stars.
RAPTOR — Security Research Agent for Claude Code
Autonomous offensive and defensive security framework built on Claude Code. Performs static analysis, binary fuzzing, vulnerability discovery, exploit generation, and patch development. MIT.
LaVague — Natural Language Web Automation
Give a text objective, LaVague drives the browser to accomplish it. Large Action Model framework for web agents. 6.3K+ stars.
Roo Code — AI Coding Agent with Custom Modes
Fork of Cline with custom agent modes, boomerang orchestration, and multi-model routing. Create specialized AI agents for coding, review, and architecture tasks.
Phidata — Build & Deploy AI Agents at Scale
Framework for building, running, and managing AI agents at scale. Memory, knowledge, tools, reasoning, and team workflows. Monitoring dashboard included. 39K+ stars.
Optio — Workflow Orchestrator for AI Coding Agents
Automates the full AI development lifecycle from task planning to merged PR. Orchestrates AI agents through planning, execution, code review, and merge. 800+ GitHub stars.
LangGraph — Build Stateful AI Agent Workflows
Framework for building stateful, multi-step AI agent workflows as graphs. LangGraph enables cycles, branching, human-in-the-loop, and persistent state for complex agent systems.
Langflow — Visual AI Agent Builder with API
Langflow is a visual platform for building and deploying AI agents as APIs or MCP servers. 146K+ GitHub stars. Multi-agent orchestration, playground, observability. MIT.
Mastra — TypeScript AI Agent Framework
Production TypeScript framework for building AI agents with tool use, workflows, RAG, and memory. First-class MCP support. Deploy anywhere Node.js runs. 9,000+ GitHub stars.
Awesome A2A — Agent-to-Agent Ecosystem Directory
Curated collection of A2A Protocol resources — official samples, SDKs for 5 languages, framework integrations, community implementations, and tutorials. The go-to directory for A2A adoption. MIT.
Mastra — TypeScript AI Agent Framework
AI agent framework for TypeScript from the Gatsby team. Build agents with tools, workflows, RAG, memory, evals, and 50+ integrations. Modern TS-native design. 22K+ stars.
FastHTML — Build AI Web Apps in Pure Python
Modern Python web framework that generates HTML from Python functions. No JavaScript, no templates. Perfect for building AI tool dashboards and agent UIs rapidly.
AgentOps — Observability Dashboard for AI Agents
Python SDK for monitoring AI agent sessions with real-time dashboards, token tracking, cost analysis, and error replay. Two lines of code to instrument any framework. 4,500+ GitHub stars.
LiveKit Agents — Build Real-Time Voice AI Agents
Framework for building real-time voice AI agents. STT, LLM, TTS pipeline with sub-second latency. Supports OpenAI, Anthropic, Deepgram, ElevenLabs. 9.9K+ stars.
Claude Forge — Plugin Framework for Claude Code
Supercharge Claude Code with 11 AI agents, 36 commands, and 15 skills. The oh-my-zsh-inspired plugin framework with 6-layer security hooks. 5-minute install. 640+ GitHub stars.
DSPy — Program LLMs Instead of Prompting
DSPy is a Python framework for programming language models instead of prompting them. 33.3K+ GitHub stars. Build modular AI systems — classifiers, RAG pipelines, agent loops — and let DSPy optimize pr
The Agent Stack in 2026
The Agent Stack in 2026
Building AI agents has evolved from prompt-chaining experiments to a mature engineering discipline with dedicated frameworks, testing tools, and deployment patterns. The modern agent stack has three layers: Foundation Models (Claude, GPT, Gemini as the reasoning engine), Orchestration Frameworks (managing tool use, memory, and multi-step workflows), and Infrastructure (deployment, monitoring, and scaling).
Single-Agent Frameworks — Tools like Claude Agent SDK, Semantic Kernel, and Goose provide structured ways to build agents that use tools, maintain conversation state, and handle complex multi-step task planning. Multi-Agent Systems — CrewAI, AutoGen, CAMEL, and LangGraph enable teams of specialized agents that collaborate, delegate, and peer-review each other's work.
Agent Infrastructure — MCP servers give agents access to external tools (databases, APIs, browsers). RAG and knowledge graph systems provide persistent context across sessions. Evaluation frameworks (AgentBench, SWE-bench) measure agent performance on real-world tasks.
The most powerful agent isn't the smartest model — it's the best-orchestrated system of specialized models working together.
Questions fréquentes
What is the best framework for building AI agents?+
It depends on your use case. For single-agent tools: Claude Agent SDK (Python/TypeScript, production-ready), Semantic Kernel (enterprise/.NET). For multi-agent: CrewAI (role-based teams), AutoGen (Microsoft, conversation-driven), LangGraph (graph-based workflows). For rapid prototyping: Mastra (TypeScript) or VoltAgent (batteries-included). TokRepo hosts starter templates for all major frameworks.
How do AI agents use tools?+
AI agents use tools through function calling — the model outputs a structured request (tool name + parameters), the framework executes it, and returns the result. MCP (Model Context Protocol) standardizes this pattern, letting agents access databases, APIs, browsers, and file systems through a universal protocol. Install MCP server configs from TokRepo to give your agent instant capabilities.
What is the difference between single-agent and multi-agent systems?+
Single-agent systems use one AI model with tools to complete tasks sequentially. Multi-agent systems use multiple specialized agents that collaborate — e.g., a researcher agent gathers data, an analyst agent processes it, and a writer agent produces the report. Multi-agent systems are better for complex tasks but harder to debug and more expensive to run.