Harness²
Harness the agent. Then harness its self-improvement.
Built by Han Yu · Artificial Intelligence · Developer Tools · Open Source
In category: #331 of 2007 · Artificial Intelligence
Harness² is a Product Hunt listing on Launch Llama with 202 total upvotes, founded by Han Yu who joined in Nov 2026, compared against 6 alternatives.
Product Hunt listing
Listing status
202upvotes
Community score
Han Yu (Joined Nov 2026)
Founder
Compared against 6 alternatives
Market comparison
Launched on Launch Llama Nov 1, 2026 · #21 of 25 that day
About
Harness² from Google Research is a plug-and-play recursive agent harnessing framework that lets LLM agents automatically evolve their execution harnesses (prompts, tools, memory) for open-world tasks—without ground-truth verifiers. Dual recursion: task-level Propose-Probe-Compose refinement + harnessing-level accumulation of reusable experience. Up to +11.5 points on professional benchmarks like WorkBuddy-Bench.
Launch Llama's Take
Based on Launch Llama data as of
Harness² has 202 upvotes, including the votes it received on Product Hunt, which ranks it #331 of 2,007 Artificial Intelligence tools on Launch Llama by upvotes, in the top quarter. It has been listed on Launch Llama since November 2026. No Launch Llama members have upvoted it yet and it has no reviews yet.
Harness² is aimed at teams building LLM agents for open-world tasks where no ground-truth verifier is available, and it works without one. HarnessRouter runs the agent backend through one API, while Harness² focuses on automatically evolving the agent's own prompts, tools, and memory.
Harness² vs HarnessRouter
Harness² is aimed at teams building LLM agents for open-world tasks where no ground-truth verifier is available, and it works without one. HarnessRouter runs the agent backend through one API, while Harness² focuses on automatically evolving the agent's own prompts, tools, and memory.
| Harness² | HarnessRouter | Pi Coding Agent | Gauge | |
|---|---|---|---|---|
| What it does | Harness the agent. Then harness its self-improvement. | For developers: HarnessRouter runs your AI agent backend via one API so you ship code, files, and videos without months of orchestration… | For developers: Pi Coding Agent adapts to your workflow with customizable extensions and skills so you build faster without forcing new h… | For developer tools: Gauge optimizes your product for AI agents so they choose your tool autonomously without sales demos. |
| Pricing | Not stated | Freemium | Free | Freemium |
| Free plan | Not stated | Yes, free plan | Yes, free to use | Yes, free plan |
| Category | Open Source | API | Open Source | SEO tools |
| Upvotes on Launch Llama | 202 | 256 | 174 | 99 |
| Listed on Launch Llama | November 2026 | July 2026 | June 2026 | August 2026 |
Key Features
- Delivers automatically evolves LLM agent prompts, tools, and memory
- Runs task-level Propose-Probe-Compose refinement
- Delivers accumulates reusable experience at the harnessing level
- Delivers operates on open-world tasks without ground-truth verifiers
Use Cases
- Teams building LLM agents for open-world tasks where no ground-truth verifier is available
- Developers who want higher scores on professional agent benchmarks such as WorkBuddy-Bench
Pricing
See the Harness² website for current pricing.
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