# Harness Analyzer — AI system prompt archive

> Primary-source archive of AI coding-agent system prompts: captured, diffed, annotated.

Harness Analyzer archives the system prompts of AI coding agents, captured from the wire: **701 versions across 4 CLIs**, every consecutive pair diffed and editorially annotated.

## The corpus

| Tool | Versions | Range | Last capture |
|---|---|---|---|
| [Claude Code](https://harness-analyzer.com/timeline/claude-code.md) | 447 | 0.2.9 → 2.1.210 | 2026-07-15 |
| [Gemini CLI](https://harness-analyzer.com/timeline/gemini.md) | 144 | 0.1.0 → 0.50.0 | 2026-07-15 |
| [Codex CLI](https://harness-analyzer.com/timeline/codex.md) | 55 | 0.93.0 → 0.144.4 | 2026-07-15 |
| [OpenCode](https://harness-analyzer.com/timeline/opencode.md) | 55 | 1.4.8 → 1.16.2 | 2026-06-05 |

## Start here (for agents)

- Agent guide: https://harness-analyzer.com/llms.txt
- Corpus manifest: https://harness-analyzer.com/data/index.json
- API docs: https://harness-analyzer.com/api.md
- License & citation: https://harness-analyzer.com/license.md
- Feeds: https://harness-analyzer.com/feeds/versions.atom · https://harness-analyzer.com/feeds/insights.atom

## Recent insights

- 2026-05-18 — [The Late-February 2026 Rewrite Cluster](https://harness-analyzer.com/insights/feb-2026-cluster.md)
- 2026-05-17 — [OpenCode's 1-Second Footgun, and the Sandbox Gradient](https://harness-analyzer.com/insights/sandbox-gradient.md)
- 2026-05-17 — [Codex 0.130.0 versus Claude Code 2.1.143](https://harness-analyzer.com/insights/codex-vs-claude-code-system-prompts.md)
- 2026-05-16 — [Never Talk About Goblins, Gremlins, Raccoons…](https://harness-analyzer.com/insights/anti-goblin-clause.md)
- 2026-05-15 — [/ultrareview — The Feature That Lived 18 Hours](https://harness-analyzer.com/insights/ultrareview-canary.md)
- 2026-05-14 — [OpenCode and Claude Code Share a Sub-Agent — Line for Line](https://harness-analyzer.com/insights/cross-tool-copying.md)

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Canonical page: https://harness-analyzer.com/ · Site: Harness Analyzer (https://harness-analyzer.com)
License: editorial layer (annotations, analyses, insights, stories, manifests) CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/. Raw captured system prompts remain © their respective vendors; see https://harness-analyzer.com/license.