Anthropic released Claude Haiku 5.5 on the Devin platform on Oct 7 2026. The model is now usable through the Devin command‑line interface, paired with Opus 5.5 as the lead model. It joins the sidekick lineup that powers Devin Fusion, a tool that combines multiple models for engineering work.
How Haiku 5.5 performs
On FrontierCode 1.1 – a proprietary benchmark that grades AI on real‑world engineering tasks – Haiku 5.5 scored 58.4 %. That puts it ahead of Anthropic’s Sonnet 5 and costs roughly an eighth per task compared with Sonnet 5. When used as a sidekick in Devin Fusion, the combined system reaches a FrontierCode score of 66.2 % while reducing both cost and latency.
Why it matters
For engineers and developers who use Devin, the new Haiku 5.5 offers higher quality output at a fraction of the cost of earlier models. This makes large‑scale engineering tasks cheaper and faster, though independent benchmarks beyond FrontierCode are not yet published.
