{"slug": "openrouter-fusion-beats-deepseek-v4-pro-on-substance", "title": "OpenRouter: Fusion beats DeepSeek-V4-Pro on substance", "summary": "OpenRouter's Fusion model outperformed DeepSeek-V4-Pro in a head-to-head coding test, delivering a complete, compilable Go rate limit parser with correct edge cases while DeepSeek V4 Pro made basic errors including missing package declarations and logic bugs.", "body_md": "OpenRouter: Fusion wins this head to head because it was better where mistakes actually cost you. In the Go rate limit parser, Fusion delivered a complete, compilable snippet and got the edge cases right: case insensitive header lookup, trimming, rejecting signed and fractional numerics, and parsing both RFC1123 and RFC1123Z. DeepSeek V4 Pro stumbled on basics here — no package declaration, an unnecessary net/http import, and a real logic bug in treating a valid integer value of \"0\" as invali...", "url": "https://wpnews.pro/news/openrouter-fusion-beats-deepseek-v4-pro-on-substance", "canonical_source": "https://runtimewire.com/article/openrouter-fusion-beats-deepseek-v4-pro-on-substance", "published_at": "2026-06-13 20:18:38+00:00", "updated_at": "2026-06-13 20:22:41.728657+00:00", "lang": "en", "topics": ["large-language-models", "ai-products", "ai-tools", "developer-tools"], "entities": ["OpenRouter", "Fusion", "DeepSeek-V4-Pro", "DeepSeek"], "alternates": {"html": "https://wpnews.pro/news/openrouter-fusion-beats-deepseek-v4-pro-on-substance", "markdown": "https://wpnews.pro/news/openrouter-fusion-beats-deepseek-v4-pro-on-substance.md", "text": "https://wpnews.pro/news/openrouter-fusion-beats-deepseek-v4-pro-on-substance.txt", "jsonld": "https://wpnews.pro/news/openrouter-fusion-beats-deepseek-v4-pro-on-substance.jsonld"}}