$ find your agent harness

A curated, verified, cross-vendor directory of AI agent harnesses — the runtime scaffolding that turns a model into an agent.

74 harnesses profiled · 9-axis capability schema · last verified 2026-07-08

16 of 74 harnesses · sorted by stars

OpenHands · All Hands AI / OpenHands

79,895 · high

Formerly OpenDevin, the leading open-source autonomous software-engineering platform: Docker-sandboxed agents that write code, run commands, browse, and open PRs, with a production agent SDK hitting 72% on SWE-bench Verified (Claude Sonnet 4.5) and its own broader OpenHands Index benchmark launched Jan 2026.

OSS coding harnessesopen-sourcefreemium✓ mcp✓ skills✓ local modelscontainer

Warp · Warp (warpdotdev)

62,928 · medium

Warp is a Rust-based GPU-accelerated 'Agentic Development Environment' (terminal app, source opened April 2026 under dual MIT/AGPL) distinguished by running multiple agents in parallel — including hosting Claude Code, Codex, and Gemini CLI — plus Oz, its cloud orchestrator for autonomous background agents, with BYOK and credit-based pricing.

Vendor CLI agentsopen-sourcefreemium✓ mcpcloud-remote

CrewAI · CrewAI Inc.

55,117 · high

MIT-licensed Python framework (~55k stars) for role-based multi-agent 'Crews' plus event-driven 'Flows', with unified memory, hierarchical delegation, and a commercial AMP cloud platform (free tier, Pro from ~$25/mo, enterprise) that CrewAI says powered ~2B agentic executions in the year to January 2026.

Runtimes & SDKsopen-sourcefreemium✓ mcp✓ local modelsoptional

LangGraph · LangChain

36,751 · high

Low-level graph-based agent orchestration runtime with automatic checkpointing, durable execution, human-in-the-loop interrupts, and streaming (v1.2 in May 2026 added typed streaming, per-node timeouts, and distributed runtime), used in production by Klarna, LinkedIn, Uber, and Replit and serving as the substrate under Deep Agents.

Runtimes & SDKsopen-sourcefreemium✓ mcp✓ local models

Continue · Continue Dev (acquired by Cursor/Anysphere)

34,732 · medium

The veteran model-agnostic IDE extension (VS Code + JetBrains, strong local-model support) that pivoted to 'Continuous AI' — a cn CLI running markdown-defined async agents as GitHub PR status checks — before being acquired by Cursor in 2026, with the original team shipping a final v2.0.0 (telemetry and auth removed).

OSS coding harnessesopen-sourcefreemium✓ mcp✓ local models

Kilo Code · Kilo (Kilo-Org)

25,785 · high

The Cline/Roo merger-fork turned all-in-one agentic platform (~26k stars, 3M+ users): IDE extension, CLI, and hosted KiloClaw background agent reachable via Telegram/Discord/Slack, with 500+ models, mid-task model switching, an MCP marketplace, subagents (GA April 2026), and optional Kilo Pass credits from $19/mo.

OSS coding harnessesopen-sourcefreemium✓ mcp✓ local modelsoptional

Letta · Letta (formerly MemGPT, UC Berkeley spinout)

23,701 · high

Apache-2.0 platform for stateful agents descended from MemGPT, distinguished by tiered self-editing memory persisted in a database (core memory in-context, archival out-of-context) plus 2026 research on git-based 'Context Repositories' and memory-native RL; in 2026 the company is consolidating around Letta Code, an open, model-agnostic memory-first coding agent harness (LettaBot archived May 2026 and folded in as Channels).

Runtimes & SDKsopen-sourcefreemium✓ mcp✓ local modelsoptional

Sweep (issue-to-PR agent) · Sweep AI

7,700 · medium

An early (2023-era) open-source background agent that turned labeled GitHub issues into pull requests by planning, coding and opening a PR asynchronously; the original bot is effectively sunset — the repo README redirects to the company's pivot into a proprietary JetBrains AI plugin (autocomplete + in-IDE agent, $10-60/mo) using Sweep's own LLMs, so the background-agent product itself is legacy.

Cloud / backgroundopen-sourcefreemiumcloud-remote

Cursor (Agent mode) · Anysphere

high

VS Code-fork AI IDE whose Agent mode plus in-house Composer models, Background/Cloud Agents (isolated cloud VMs that report back as PRs), hooks, skills, and an agent SDK make it the most fully-built-out commercial agentic IDE; Composer 2 scored 61.7% on Terminal-Bench 2.0 and Composer 2.5 79.8% on SWE-bench Multilingual (SWE-bench Verified not reported).

IDE & desktopproprietaryfreemium✓ mcp✓ skillsoptional

Windsurf Cascade / Devin Desktop (Devin Local) · Cognition AI (formerly Codeium)

medium

The Windsurf AI IDE's Cascade agent, post-Cognition-acquisition, was rebranded to Devin Desktop (June 2, 2026) with Cascade deprecated (available through July 1, 2026) in favor of the Rust-rewritten 'Devin Local' agent (30% more token-efficient, subagents), pairing local agentic editing (Fast Context codebase awareness, MCP, Memories, Workflows) with Devin cloud sessions for background work.

IDE & desktopproprietaryfreemium✓ mcpoptional

GitHub Copilot agent mode (VS Code) · GitHub / Microsoft

high

Copilot's agent mode inside VS Code (extension itself MIT open-sourced; backend service proprietary) iterates on errors, runs tools/terminal, and applies multi-file edits, distinguished by deep GitHub-ecosystem reach: MCP support, SKILL.md Agent Skills (added April 2026), custom .agent.md agents, a multi-vendor model picker with Ollama BYOK, and a cloud 'coding agent' that works issues into PRs on GitHub Actions.

IDE & desktopopen-sourcefreemium✓ mcp✓ skills✓ local modelsoptional

JetBrains Junie · JetBrains

medium

JetBrains' autonomous coding agent for IntelliJ-family IDEs (plus a Junie CLI that left beta March 2026 with BYOK/OpenRouter routing and CI/CD support), distinguished by leverage of the IDE's code index, a confirmation-gated loop with opt-in 'Brave Mode', Docker/worktree-isolated parallel tasks, remote cloud execution mode, and a companion Claude Agent built on Anthropic's Agent SDK.

IDE & desktopproprietaryfreemium✓ mcp✓ local modelsoptional

Jules · Google

high

Google's asynchronous coding agent that clones your GitHub repo into a secure cloud VM, plans and executes tasks (bug fixes, tests) and returns PRs; free tier of 15 tasks/day with higher quotas bundled into Google AI Pro/Ultra, Gemini 3.1 Pro/3 Flash under the hood, curated MCP connections (Linear, Supabase, Neon, Context7) added Feb 2026 and an alpha REST API for Slack/Linear-driven automation.

Cloud / backgroundproprietaryfreemium✓ mcpvm

Manus · Butterfly Effect Pte Ltd (Singapore; ex-Monica)

high

The viral general-purpose autonomous agent that plans and executes multi-step tasks in a cloud VM (browsing, code, docs, slides), notable for Wide Research parallel sub-agents and for Meta's $2B acquisition being blocked by China's NDRC in April 2026.

General / computer-useproprietaryfreemiumcloud-remote

Genspark Super Agent (+ Genspark Claw) · Genspark (MainFunc Inc.)

medium

Credit-based all-in-one 'AI employee' workspace whose Super Agent mixes multiple frontier models with 80+ tools to produce slides, sheets, sites, and calls, and whose 2026 'Genspark Claw' gives each user a persistent cloud computer commandable from WhatsApp/Telegram/Slack/Teams.

General / computer-useproprietaryfreemiumcloud-remote

Runner H · H Company (Paris)

medium

Cloud web-agent from DeepMind-alumni startup H Company ($220M seed) that orchestrates sub-agents over its own Holo vision-language action models (92.2% WebVoyager at ~$0.13/task via open-sourced Surfer-H), with Holo 3 in 2026 targeting any-UI enterprise automation.

General / computer-useproprietaryfreemium✓ local modelscloud-remote
harnesses.sh — the agent harness directory