When will Anthropic release Claude 4 and make it generally available?

For the purposes of this question, Claude 4 must be a frontier model that Anthropic claims to be more intelligent or powerful than any previous Anthropic model.

For example, if they release Claude 4 Sonnet first, as they did with 3.5, and 4 Sonnet is superior to their previous best model (e.g. 3.5 Opus), that resolves this question YES. However, if they release 4 Haiku first, and it does not surpass 3.5 Opus, that does not resolve this question. I'll defer to Anthropic's characterizations of their models for this purpose.

If Anthropic abandons their number-based naming scheme, I'll resolve it to when "Claude 4 in spirit" comes out, if it's clear when such a model is released. But if it's not clear, it will resolve to the last time option.