AgentScout / By role / AI engineers

AI agent tools for AI engineers (2026)

Frameworks, memory, MCP, evals and observability for engineers who build and run their own agents. We picked the top tools for 7 jobs AI engineers do every day: 36 tools in all, 36 of them free or with a free tier.

Jump to: Build agents · Multi-agent systems · Memory · Build MCP servers · Evaluate agents · Monitor in production · Deploy and host

Free tools from AgentScout for AI engineers: AI API cost calculator · Agent setup generator

How we picked: each section takes the tools matched to that task in our directory, putting tools whose category and stated use cases fit the task first, then ordering by tracked GitHub stars. No paid placements.

Build agents

Frameworks and SDKs for developers building their own agents, with tools, state and orchestration built in. All 137 tools →

Hermes Agent (Nous Research) Open source
Open-source agent harness; v0.21.7 stable shipped Oct 12, v0.22.0 RCs Oct 13-14. · ★ 253,590
DeepSeek Harness Open source
DeepSeek's open-source agent harness with a local web UI, built so that every tool, model and scheduled task is a swappable plugin; still a developer preview. · ★ 251,853
AutoGPT Open source + cloud
One of the first autonomous agent projects, now a platform for building, deploying and running continuous AI agents that automate workflows. · ★ 187,612
RAGFlow Open source + cloud
Open-source RAG engine with deep document parsing and agent features for building grounded question-answering over your files. · ★ 92,335
Ruflo Open source
Open-source multi-agent meta-harness for Claude Code, Codex, and MCP clients; Oct 13 release adds Mods (mission workflows) and a single control plane with human approval. · ★ 74,609
MetaGPT Open source
Multi-agent framework that assigns roles like product manager and engineer to LLM agents to build software. · ★ 70,885

Multi-agent systems

Frameworks for teams of agents that hand work to each other, split tasks and check each other's output. All 41 tools →

Ruflo Open source
Open-source multi-agent meta-harness for Claude Code, Codex, and MCP clients; Oct 13 release adds Mods (mission workflows) and a single control plane with human approval. · ★ 74,609
AutoGen Open source
Microsoft's framework for multi-agent conversations, now archived and no longer maintained; Microsoft points new users to Microsoft Agent Framework. · ★ 61,395
CrewAI Open source + cloud
Framework for role-based multi-agent crews. · ★ 59,675
Agno Open source + cloud
Python framework and runtime for building, running and managing multi-agent systems with memory, knowledge and tools. · ★ 42,769
AgentScope Open source
Framework for building and running transparent multi-agent applications with visual debugging. · ★ 33,376
PentAGI Open source
Autonomous multi-agent system for running penetration testing tasks. · ★ 30,728

Memory

Memory layers that let agents remember users, past conversations and facts across sessions. All 29 tools →

Claude-Mem Open source
Gives coding agents memory across sessions by capturing what they do, compressing it and feeding the relevant context back in later. · ★ 101,230
Mem0 Open source + cloud
Memory layer for AI agents. · ★ 67,147
Hindsight Open source + cloud
Agent memory system that stores experiences and learns from them so agents improve over time. · ★ 50,483
Nanobot Open source
Ultra-lightweight, self-hosted personal agent framework in Python with a web UI, tools, memory and MCP support. · ★ 49,096
Codebase Memory MCP Open source
MCP server that indexes codebases into a persistent knowledge graph so coding agents can look up structure quickly. · ★ 46,717
Agno Open source + cloud
Python framework and runtime for building, running and managing multi-agent systems with memory, knowledge and tools. · ★ 42,769

Build MCP servers

Tools and SDKs for building, hosting and publishing your own MCP servers. All 118 tools →

REA Open source
MCP server and CLI that lets coding agents reverse engineer native binaries, Electron and JavaScript apps, .NET assemblies and live websites, using Ghidra, Hopper or IDA under the hood. · ★ 301,645
Langflow Open source + cloud
Visual drag-and-drop builder for AI agents and workflows that you can run locally, deploy as an API or expose as an MCP server. · ★ 155,757
MCP reference servers Open source
Official collection of reference MCP servers. · ★ 91,237
Context7 Freemium
MCP server and platform that feeds coding agents up-to-date, version-specific library documentation. · ★ 63,157
Chrome DevTools MCP Open source
Official MCP server that lets coding agents control and inspect a live Chrome browser through DevTools for debugging and performance work. · ★ 53,681
Codebase Memory MCP Open source
MCP server that indexes codebases into a persistent knowledge graph so coding agents can look up structure quickly. · ★ 46,717

Evaluate agents

Evaluation tools for scoring agent outputs, catching regressions and comparing prompts and models. All 57 tools →

MLflow Open source + cloud
Open-source platform for tracing, evaluating and managing agents, LLM apps and ML models. · ★ 28,418
Arize Phoenix Open source
Open-source tracing and evaluation for LLM apps. · ★ 11,828
Guardrails AI Open source + cloud
Open-source framework for validating LLM inputs and outputs with configurable guardrails. · ★ 7,529
AI-Infra-Guard Open source
Tencent's AI red-teaming platform that scans agents, skills and MCP servers for risks. · ★ 6,887
Agent Governance Toolkit Open source
Microsoft toolkit for policy enforcement, identity and sandboxing for AI agents. · ★ 6,435
Failproof AI Open source
Observability and policy enforcement for AI agent harnesses. · ★ 5,560

Monitor in production

Observability for agents in production: traces, costs, latency and errors in one place. All 16 tools →

MLflow Open source + cloud
Open-source platform for tracing, evaluating and managing agents, LLM apps and ML models. · ★ 28,418
Arize Phoenix Open source
Open-source tracing and evaluation for LLM apps. · ★ 11,828
Failproof AI Open source
Observability and policy enforcement for AI agent harnesses. · ★ 5,560
agentgateway Open source
Proxy for AI agents and MCP servers with security and observability. · ★ 5,373
Agenta Open source + cloud
Open-source LLMOps platform for prompt management, evaluation and observability. · ★ 4,840
Cloudflare MCP Servers Open source
Cloudflare's collection of MCP servers for Workers, observability, DNS analytics and other Cloudflare services. · ★ 4,387

Deploy and host

Infrastructure for running agents in production: hosting, scaling and serverless runtimes. All 13 tools →

Sim Studio Open source + cloud
Workspace for visually building, deploying and monitoring AI agents and workflows. · ★ 29,835
Google ADK Open source
Google's Agent Development Kit for building and deploying agents. · ★ 21,826
Trigger.dev Open source + cloud
Platform for building and deploying durable background AI agents and workflows in TypeScript. · ★ 16,558
VoltAgent Open source + cloud
TypeScript agent framework plus an engineering platform for building, observing and deploying AI agents. · ★ 10,819
Nasiko Open source
Open runtime for deploying and operating AI agents. · ★ 9,479
Open Multi-Agent Open source
Self-hosted TypeScript agent runtime with durable approvals and verifiable run records. · ★ 7,001