New ReleaseJune 29, 2026 ยท 5 min read

๐Ÿฆ Ornith 1.0: Self-Scaffolding Coding Agents

A new family of open-source coding models learns to write its own agent harness during training โ€” and the 397B variant beats Claude Opus 4.7 on Terminal-Bench.

๐Ÿ“‹ Article Summary

  • ๐Ÿ”‘ Self-Scaffolding Explained โ€” Model jointly learns harness + solution, not just answers
  • ๐Ÿ—๏ธ Two-Stage RL โ€” Scaffold generation โ†’ solution rollout โ†’ GRPO reward to both
  • ๐Ÿ›ก๏ธ Anti-Reward-Hacking โ€” Immutable env + deterministic monitor + LM judge veto
  • ๐Ÿ“Š Benchmarks โ€” 397B: 82.4% SWE-bench, 77.5% Terminal-Bench. 9B: edge-deployable
  • ๐Ÿ’ก Why It Matters โ€” First framework where orchestration is learned, not hand-engineered

The Innovation

DeepReinforce's Ornith-1.0 is a family of four models (9B Dense, 31B Dense, 35B MoE, 397B MoE) fine-tuned from Qwen 3.5 and Gemma 4. The breakthrough isn't the base architecture โ€” it's the training method: the model learns to write its own agent harness during reinforcement learning.

How It Works

  1. Scaffold Generation โ€” Model reads task + previous scaffold, proposes refined harness.
  2. Solution Rollout โ€” Uses that scaffold to generate solution. Reward flows back to both stages.
  3. GRPO Optimization โ€” Updates weights for both scaffold and solution quality.

Anti-Reward-Hacking

  • โ€ข Immutable environment โ€” Sandbox tools can't be modified by model
  • โ€ข Deterministic monitor โ€” Watches for unauthorized tool use, immediate penalty
  • โ€ข LM judge veto โ€” Can override automated checks if solution seems suspicious

Benchmark Results

ModelSWE-BenchTerminal-BenchParams
Ornith 397B82.477.5397B MoE
Ornith 35B75.664.435B MoE
Ornith 9B69.443.19B Dense
Claude Opus 4.780.870.3~500B+
DeepSeek V4 Pro80.667.91.6T/49B

Key takeaway: The 397B variant beats Claude Opus 4.7 on Terminal-Bench (77.5 vs 70.3) and matches it on SWE-bench. The 9B punches well above its weight at 69.4% SWE-bench. All MIT-licensed with open weights.