Sonnet 5 launches: Opus performance at lower cost
This week was largely a Claude story: Sonnet 5 landed with enough benchmark muscle to make Opus feel redundant for most workloads, and GitLab's production data backs up the claims. Alongside that, GitHub Copilot quietly dropped its JetBrains friction, and Google's image model got cheaper and faster on Vercel's gateway. Here's what's worth acting on. Claude Sonnet 5 launches on Vercel AI Gateway Sonnet 5 is available now via Vercel AI Gateway at anthropic/claude-sonnet-5 . Launch pricing is $2/$10 per million input/output tokens—identical to Sonnet 4.6—but that rate expires August 31, after which it steps to $3/$15. The model matches Opus 4.8 on coding and agentic benchmarks, which means you can stop routing hard tasks to Opus and absorb a 50–67% cost reduction in the process. For AI SDK users, this is a one-line change. Stronger long-context handling and document parsing are the practical wins for RAG pipelines and multi-turn agent workflows—two areas where Sonnet 4.6 had real rough edges. Verdict: Ship. Update your model identifier before August 31 while the launch pricing holds. Zero breaking changes, and there's no reason to stay on 4.6 for new work. Sonnet 5 closes Opus gap at lower cost Beyond the Vercel integration, the broader Sonnet 5 release deserves its own read. The model is now the default reasoning tier replacing Sonnet 4.6 across Anthropic's plans, and the capability jump is specifically on agentic task completion—planning, multi-step tool use, brownfield code navigation. Early testers report that tasks which previously stalled midway through agent loops now finish end-to-end, which is a qualitatively different outcome from incremental benchmark gains. The economics are straightforward: Opus-level performance at Sonnet prices through August, then a modest step up to $3/$15. If you're running production agents today, the cost-per-completed-task improvement compounds because you're paying less and spending fewer cycles on failure recovery and re-promptin