Even Claude Opus 4.5 can’t remember its own API ID 😆
I tried using Claude Code to program an app that uses Sonnet 4.5, but Opus came up with the wrong model ID almost every time. Presumably, the model training cutoff date was before Sonnet 4.5 was launched. It could search online, but…
The solution? I created a Claude Skill that explicitly mentions the correct ID (claude-sonnet-4-5-20250929). Works perfectly now.
Originally posted on LinkedIn.