How do I install the Agent Harness Landscape skill?

Run npx skillmds@latest add cyberuni/agent-harness-landscape in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Agent Harness Landscape safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Agent Harness Landscape?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Agent Harness Landscape free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Agent Harness Landscape?

cyberuni (@cyberuni) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Agent Harness Landscape by cyberuni

Name: Agent Harness Landscape
Author: cyberuni

Agent Harness Landscape

Use this skill when research, website content, a spec, or an ADR compares, surveys, or lists agent harnesses (coding agents / AI coding CLIs) — it supplies the canonical comparison set so the list is consistent across sessions instead of ad-hoc from memory.

cyberuni Updated Sep 17, 2026

File contents

Agent harness landscape

The canonical comparison set for this repo. Treat the tiers below as the floor: don't drop a tool from the always-include tier without updating this skill first. Re-derive membership from current sources when the stakes are published output — the space moves fast.

Always include

Harness	Vendor	Notes (as of 2026-07)
Claude Code	Anthropic	Wins on capability/context (per 2026 roundups); hook system, subagents
Cursor	Cursor / Anysphere	Wins on UX in most 2026 comparisons
Codex CLI	OpenAI	#1 on several benchmarks as of GPT-5.6 GA, July 2026
GitHub Copilot CLI	GitHub / Microsoft	Vendor-native, IDE + terminal
Gemini CLI	Google	Vendor-native

Secondary tier — include if relevant to the comparison's scope

Harness	Notes
Cline	Open-source, VS Code-hosted agent; appears in most "front-runner" 2026 lists
OpenCode	Model-agnostic open-source CLI; appears in most 2026 "top CLI tools" lists

Excluded from the standing list

Checked 2026-07; re-verify before reusing.

Windsurf — real product, consolidated after a 2025 acquisition; not a front-runner in 2026 roundups. Include only when the comparison is explicitly about IDE-integrated agents or acquisition history.
Aider — real, older terminal-first tool; absent from current 2026 front-runner lists. Include only for comparisons scoped to open-source or legacy tooling.
OpenClaw, Hermes — no evidence of these as established agent harnesses as of 2026-07. Do not include without a specific source naming them.

Framing

Agent = Model + Harness. Separate what is attributable to the underlying model (GPT-5.6, Opus 5, Gemini) from what is attributable to the harness (context management, tool design, retry and failure handling, hook system). Two tools on the same backend can differ purely on harness design.

Freshness

If the "as of" dates above are more than ~2 months stale and the output is published (website, spec, ADR), run a fresh web sweep first, then update the tiers here in place.

---name: agent-harness-landscapedescription: Use this skill when research, website content, a spec, or an ADR compares, surveys, or lists agent harnesses (coding agents / AI coding CLIs) — it supplies the canonical comparison set so the list is consistent across sessions instead of ad-hoc from memory.---# Agent harness landscapeThe canonical comparison set for this repo. Treat the tiers below as the floor: don't drop a tool from the always-include tier without updating this skill first. Re-derive membership from current sources when the stakes are published output — the space moves fast.## Always include| Harness | Vendor | Notes (as of 2026-07) || --- | --- | --- || Claude Code | Anthropic | Wins on capability/context (per 2026 roundups); hook system, subagents || Cursor | Cursor / Anysphere | Wins on UX in most 2026 comparisons || Codex CLI | OpenAI | #1 on several benchmarks as of GPT-5.6 GA, July 2026 || GitHub Copilot CLI | GitHub / Microsoft | Vendor-native, IDE + terminal || Gemini CLI | Google | Vendor-native |## Secondary tier — include if relevant to the comparison's scope| Harness | Notes || --- | --- || Cline | Open-source, VS Code-hosted agent; appears in most "front-runner" 2026 lists || OpenCode | Model-agnostic open-source CLI; appears in most 2026 "top CLI tools" lists |## Excluded from the standing listChecked 2026-07; re-verify before reusing.- **Windsurf** — real product, consolidated after a 2025 acquisition; not a front-runner in 2026 roundups. Include only when the comparison is explicitly about IDE-integrated agents or acquisition history.- **Aider** — real, older terminal-first tool; absent from current 2026 front-runner lists. Include only for comparisons scoped to open-source or legacy tooling.- **OpenClaw, Hermes** — no evidence of these as established agent harnesses as of 2026-07. Do not include without a specific source naming them.## FramingAgent = Model + Harness. Separate what is attributable to the underlying model (GPT-5.6, Opus 5, Gemini) from what is attributable to the harness (context management, tool design, retry and failure handling, hook system). Two tools on the same backend can differ purely on harness design.## FreshnessIf the "as of" dates above are more than ~2 months stale and the output is published (website, spec, ADR), run a fresh web sweep first, then update the tiers here in place.

Frequently asked questions