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Harnesses

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Created: / Updated: / Status: in progress / Readability: 3 / 4 minutes read (~634 words)
agents 42 harnesses 27

The terminal and CLI agents that carry the model into your repository: the platform benchmarks, the provider entrants, and the minimal, self-extensible, and foundation-governed outliers.

  • aider - the pre-agentic BYOK pair-programmer, cheapest precise-edit tool, development stalled since May 2026.
  • Amp - Sourcegraph-spun-out agent whose orbs keep working after you close the laptop, free on your own compute, subscriptions, or keys since September 13.
  • Ante - Antigma Labs’ ~15MB Rust harness with an embedded llama.cpp engine, offline GGUF or 12+ cloud providers, footprint as the product.
  • Bullet - TryBullet’s closed-source YC S26 latency bet, free today, with a published 479-of-500 SWE-bench run.
  • Claude Code - Anthropic’s everywhere-at-once harness, the platform benchmark and the token-cost cautionary tale.
  • Cline - the open-source agent that outgrew its VS Code extension into CLI, kanban, and SDK, 5.3 million installs deep.
  • Codex - OpenAI’s ChatGPT-included agent, the Apache-2.0 big-lab CLI individuals can still just run.
  • Crush - Charm’s Go-and-LSP terminal agent, FSL-licensed, from the original OpenCode repo.
  • DeepSeek Harness - DeepSeek’s everything-is-a-plugin harness, 228k stars in its first two months, MIT, prerelease-only at v0.1.6-alpha.2.
  • Exo - the MIT self-modification bet, a harness the agent can rewrite at runtime, cheapest measured harness at $1.05 per task.
  • fx - Vercel Labs’ ~6 MiB Zig harness built to be embedded, the first agent-as-a-dependency bet.
  • Gemini CLI - Google’s open-source terminal agent, superseded for individuals by Antigravity CLI in June 2026.
  • goose - Block’s Rust agent turned Linux Foundation project, the field’s first foundation-governed harness.
  • Grok Build - SpaceXAI’s Apache-2.0 Rust TUI agent, open-sourced to a 590-point thread, daily releases synced from the monorepo, the wire-level privacy analysis attached.
  • jcode - Solo Systems’ Rust harness for parallel agents, RAM floor, native memory and swarm, self-dev included.
  • Juggler - Julian Storer’s AGPL Go GUI agent, conversations as branchable trees with every tool call inspectable.
  • Junie - JetBrains’ plan-first agent with BYOK, IDE-grade grounding, and a free on-device Local mode for Mac.
  • Kilo Code - the Cline-and-Roo feature-merge under MIT, subagents through cloud tasks bundled in, Anaconda’s since July 2026.
  • Kimi Code - Moonshot AI’s terminal agent tuned for its own challenger-priced models, subagents through ACP in one Node.js CLI.
  • OneCLI - the YC S26 Apache-2.0 team harness where a credential gateway injects secrets per request, so agents never hold them.
  • OpenCode - the MIT, provider-neutral harness with the leanest measured token baseline.
  • OpenHands - the renamed OpenDevin platform bet, sandboxed code-shell-browser agents you can self-host.
  • Pi - Earendil’s minimal, self-extensible harness, a frozen core plus your TypeScript extensions, no MCP by design.
  • Qwen Code - Alibaba’s Gemini CLI fork and open-weights showcase, its OAuth free tier discontinued April 2026.
  • Warp Agent CLI - Warp’s terminal agent unbundled into any terminal, model routing, cloud agents, and orchestration behind its credit meter.
  • ZCode - Z.ai’s official GLM workbench, caught silently uploading whole workspaces in September 2026 and open-sourced three days later as a flattened dump.
  • Zerostack - the solo GPL-3.0 Rust agent, 26 MB binary and ~16 MB RAM, subagents, worktrees, hooks, MCP behind compile flags.

Its members are compared on shared rows in the Harness Feature Matrix.

Changes
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  • 2026-08-22 - Added aider.
  • 2026-08-22 - Added Amp.
  • 2026-08-22 - Added Claude Code.
  • 2026-08-22 - Added Codex.
  • 2026-08-22 - Added Crush.
  • 2026-08-22 - Added Gemini CLI.
  • 2026-08-22 - Added Junie.
  • 2026-08-22 - Added OpenCode.
  • 2026-08-24 - Added Cline.
  • 2026-08-24 - Added goose.
  • 2026-08-24 - Added Qwen Code.
  • 2026-08-27 - Added Kilo Code.
  • 2026-08-27 - Added OpenHands.
  • 2026-08-29 - Added fx.
  • 2026-08-30 - Added Ante.
  • 2026-08-30 - Added Bullet.
  • 2026-08-30 - Added DeepSeek Harness.
  • 2026-08-30 - Added jcode.
  • 2026-08-30 - Added Juggler.
  • 2026-08-30 - Added OneCLI.
  • 2026-08-30 - Added Pi.
  • 2026-08-30 - Added Warp Agent CLI.
  • 2026-08-30 - Added Zerostack.
  • 2026-09-05 - Added Exo.
  • 2026-09-05 - Added Kimi Code.
  • 2026-09-12 - Added Grok Build.
  • 2026-09-21 - Added ZCode.