Models on Tokenise

Moving to Sonnet 5.5? Four requests that now return a 400

Mon, 05 Oct 2026 23:18:00 +0000

Claude Sonnet 5.5 shipped on September 28 at the same price as Sonnet 5: $2 per million input tokens and $10 per million output. Anthropic says it runs 30% or more faster. If you call the API directly, though, changing claude-sonnet-5 to claude-sonnet-5-5 isn’t the whole migration. Several requests that worked yesterday now fail.

That 2-point benchmark lead might just be a bigger server

Sat, 03 Oct 2026 12:00:00 +0000

Every model launch comes with a table of coding benchmark scores, and the gaps are often a few points. Anthropic’s engineering team published a study that should make you read those gaps more carefully. In its infrastructure noise analysis , it found that how much compute an eval runs on can move agentic coding scores by more than the leaderboard gap between top models.

Claude Opus 5.5 costs 20% less per token and Anthropic says it codes better

Fri, 02 Oct 2026 12:00:00 +0000

Anthropic released Claude Opus 5.5 on September 22. The model id is claude-opus-5-5, it’s on the Claude Platform, AWS, Google Cloud and Azure, and it’s cheaper than the model it replaces. The announcement says it does most work at the level of Claude Fable 5.1 while costing 40% less to run than Opus 5.