Frequently asked questions
What is the best agent harness if I want a turnkey coding agent today?
Top picks: opencode, Cline, Codex. See the “Coding agent products (IDEs, CLIs, full suites)” category for the full ranked list.
What is the best agent harness if I want an always-on personal agent that lives in my chat apps?
Top picks: OpenClaw, Hermes, Khoj. See the “Personal agent runtimes” category for the full ranked list.
What is the best agent harness if I want to extend Claude Code, Codex, or OpenCode with skills and slash commands?
Top picks: Anthropic Skills, everything-claude-code, superpowers. See the “Coding harness configs and SDKs” category for the full ranked list.
What is the best agent harness if I want to build my own coding harness from scratch?
Top picks: Claude Agent SDK, Google ADK, AutoHarness. See the “Coding harness configs and SDKs” category for the full ranked list.
What is the best agent harness if I want a drop-in memory layer for agents?
Top picks: Mem0, claude-mem, agentlog. See the “Plugins, MCPs, CLI tools” category for the full ranked list.
What is the best agent harness if I want to plug hundreds to thousands of tools without context bloat?
Top picks: MCP-Zero, ToolGen, ToolRAG. See the “Progressive disclosure harnesses” category for the full ranked list.
What is the best agent harness if I want multi-agent orchestration?
Top picks: openai-agents-python, crewAI, autogen. See the “Multi-agent and orchestration” category for the full ranked list.
What is the best agent harness if I want a general LLM app framework?
Top picks: langgraph, langchain, llama-index. See the “Frameworks” category for the full ranked list.
What is the best agent harness if I want low-code / visual workflows?
Top picks: langflow, Flowise, Dify. See the “Frameworks” category for the full ranked list.
What is the best agent harness if I want browser-using agents?
Top picks: browser-use, WebVoyager, puppeteer-real-browser-mcp. See the “Plugins, MCPs, CLI tools” category for the full ranked list.
What is the best agent harness if I want sandboxed code execution for agent-generated code?
Top picks: E2B, Daytona, smolagents. See the “Libraries and SDKs” category for the full ranked list.
What is the best agent harness if I want to evaluate or benchmark agents?
Top picks: SWE-bench, AgencyBench, inspect_ai. See the “Evaluation and benchmarking harnesses” category for the full ranked list.
What is the best agent harness if I want a deep research / autonomous research agent?
Top picks: deepagents, gpt-researcher, openagents. See the “Research and task-specific harnesses” category for the full ranked list.
What is the best agent harness if I want a provider-agnostic LLM pipe (not a framework)?
Top picks: LiteLLM, vercel/ai. See the “Libraries and SDKs” category for the full ranked list.
Which agent harnesses can run unattended (headless)?
Harnesses designed for unattended runs, batches, and fleets: opencode, OpenHands, goose, SWE-agent, Claude Agent SDK, RepoMaster, OpenClaw, Hermes.
Which agent harnesses survive a crash mid-task (durable)?
Harnesses whose execution state persists across restarts: langgraph-bigtool, n8n, langgraph, mastra, letta, deepagents, pydantic-ai, Cloudflare Agents.
How many of these agent harnesses are open source?
96 of 110 carry a standard open-source license; the rest are source-available or unclear, and flagged per row.
What is an agent harness?
The runtime that turns a model into an agent: it decides what the model's reasoning is allowed to touch, and supplies the orchestration, tool wiring, memory, error recovery, and guardrails around per-turn inference.
How is this list ranked?
By relevance to harness concerns (environment, orchestration, lifecycle, guardrails) and by GitHub stars (captured 2026-06-21); each project also carries an adoption-surface tier and autonomy/recovery scores.
How can an AI agent use this list directly?
Three machine-readable surfaces: harnesses.json (structured), llms.txt (one file), and an MCP server (uvx agent-harnesses-mcp) exposing pick_harness and search_harnesses.