In a post on X, @chetaslua says Claude Sonnet 5.5 is being grey tested in Claude Code. The post describes the model as fast and efficient and lists prices for input, output and cache reads, but it does not establish an official Anthropic release or general availability.

Image shared by @chetaslua on X
Image shared by @chetaslua on X

Image credit: @chetaslua on X

What the post reports about Claude Sonnet 5.5

The post says Sonnet 5.5 is currently being tested in Claude Code. It describes the model as “insanely fast” and efficient, and says it has the “human touch” associated with Sonnet 4. These are the poster’s impressions, not measured results: no benchmark, workload, test conditions or comparison data is provided.

The post also says a comparison with “sol 6” is coming. That comparison is not included, so there are no reported results or test details to assess how Sonnet 5.5 performs against another model.

Reported pricing

The post lists these figures:

  • Input: $2

  • Output: $10

  • Cache reads: $0.20/M

The post does not specify the billing units for the input and output prices. It writes the cache-read figure as “$0.20/M” without defining what “M” represents. Those omissions make the figures difficult to compare with other model prices.

What remains unconfirmed

Nothing in the post establishes that Anthropic has officially announced Claude Sonnet 5.5 or that the model is generally available. The report also does not explain how broad the Claude Code testing is, whether access is limited to selected users, or how someone would obtain access beyond the post’s instruction to use Claude Code.

For now, the report is best understood as an early account of possible Claude Sonnet 5.5 testing, rather than a confirmed release or pricing announcement.

Sources