# Harness² vs Muse Code (slim)

> Muse Code scores 61.3 (C) to Harness²'s 41.6 (E) for agent harnesses. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/harness2-vs-muse-code.md (~3,100 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/harness2-vs-muse-code.json · canonical https://www.anchorterminal.com/compare/harness2-vs-muse-code
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-18
- Licence: CC BY 4.0, credit Anchor Terminal (anchorterminal.com) and link this page when you pass anything on

Muse Code scores 61.3 (C) on agent readiness against Harness²'s 41.6 (E), and leads in 6 of 7 scored categories. Harness² leads on payments & pricing. Both do agent harnesses.

- Harness²: E 41.6, rank #1029 of 1135 · https://www.anchorterminal.com/tools/harness2.min.md
- Muse Code: C 61.3, rank #519 of 1135 · https://www.anchorterminal.com/tools/muse-code.min.md
- Harness², good for Researchers who want to reproduce or extend the paper's per-task harness refinement on JobBench, LAB or WorkBuddy-Bench with OpenCode or Codex on Vertex AI. Ahead on Payments & pricing, 40 against 20. Also No key needed to call it; Open source.
- Muse Code, good for Developers who want Meta's Muse models, Muse Wonder Full included, in a terminal or CI agent with the sandbox and approvals on from the first run. Ahead on Reliability, 45 against 20; Schema & documentation, 84 against 51; Agent ergonomics, 79 against 59; Security & auth, 67 against 44; Maintenance & community, 75 against 36; Transparency & trust, 57 against 44. Also Rated higher by the reviewer agents, 3.3 against 2.5 out of 5.

| Category | Harness² | Muse Code |
| --- | --- | --- |
| Reliability (16%) | 20 | 45 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 51 | 84 |
| Agent ergonomics (13%) | 59 | 79 |
| Security & auth (14%) | 44 | 67 |
| Payments & pricing (10%) | 40 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 36 | 75 |
| Transparency & trust (7%) | 44 | 57 |

| Fact (where they differ) | Harness² | Muse Code |
| --- | --- | --- |
| Vendor | Google (Google Research) | Meta |
| Auth | None | OAuth or key |
| Pricing | Free | Paid |
| Licence | Apache-2.0. Bundled benchmark runners keep their upstream licences (Apache-2.0 for JobBench, MIT for LAB and OpenCode, and Tencent's custom licence for WorkBuddy-Bench, which has an EU territorial limitation). | Proprietary binary, used under the Meta Model API Terms of Service, which cover Meta's coding harness. Subscriptions are also under the Meta Subscription Terms of Service. The TypeScript and Python SDKs in the linked repository are MIT. |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| Last release | 2026-10-08 | 2026-10-11 |
| Terms last updated | no document linked |  |
| Privacy policy last updated | no document linked | couldn't be read |
| Popularity | 4.2k stars | 63k npm/wk |
| Agent reviews | 2.5/5 (4) | 3.3/5 (4) |