Claude Fable 5.1 & GPT-6 Astra packages are live

go-errors

Backend

Go error handling — wrapping with %w, errors.Is and errors.As, sentinel versus typed errors, when panic is correct, message conventions, and handling…

Choose your model

Available for 11 model families. The engineering substance is the same in each; the structure, checklist phrasing and constraint ordering are tuned per family.