OmniCoder-9B | 9B coding agent fine-tuned on 425K agentic trajectories

Posted by DarkArtsMastery@reddit | LocalLLaMA | View on Reddit | 146 comments

# Overview **OmniCoder-9B** is a 9-billion parameter coding agent model built by [Tesslate](https://tesslate.com/), fine-tuned on top of [Qwen3.5-9B](https://huggingface.co/Qwen/Qwen3.5-9B)'s hybrid architecture (Gated Delta Networks interleaved with standard attention). It was trained on **425,000+ curated agentic coding trajectories** spanning real-world software engineering tasks, tool use, terminal operations, and multi-step reasoning. The training data was specifically built from **Claude Opus 4.6 agentic and coding reasoning traces**, targeting scaffolding patterns from Claude Code, OpenCode, Codex, and Droid. The dataset includes successful trajectories from models like Claude Opus 4.6, GPT-5.4, GPT-5.3-Codex, and Gemini 3.1 Pro. The model shows strong agentic behavior: it recovers from errors (read-before-write), responds to LSP diagnostics, and uses proper edit diffs instead of full rewrites. These patterns were learned directly from the real-world agent trajectories it was trained on. # [](https://huggingface.co/Tesslate/OmniCoder-9B#key-features)Key Features * **Trained on Frontier Agent Traces** : Built from Claude Opus 4.6, GPT-5.3-Codex, GPT-5.4, and Gemini 3.1 Pro agentic coding trajectories across Claude Code, OpenCode, Codex, and Droid scaffolding * **Hybrid Architecture** : Inherits Qwen3.5's Gated Delta Networks interleaved with standard attention for efficient long-context processing * **262K Native Context** : Full 262,144 token context window, extensible to 1M+ * **Error Recovery** : Learns read-before-write patterns, responds to LSP diagnostics, and applies minimal edit diffs instead of full rewrites * **Thinking Mode** : Supports `<think>...</think>` reasoning chains for complex problem decomposition * **Apache 2.0** : Fully open weights, no restrictions [https://huggingface.co/Tesslate/OmniCoder-9B](https://huggingface.co/Tesslate/OmniCoder-9B)