What
Claude Code now returns a separate, cheaper set of token costs for the model id claude-opus-5-5, distinct from the pricing used for claude-opus-4-8 and claude-opus-5. The new tier covers input tokens, output tokens, prompt cache writes (both standard and 1-hour cache writes), and prompt cache reads.
Why
If your account uses claude-opus-5-5, cost tracking and any cost-based logic in Claude Code will reflect these lower rates rather than the rates applied to the other Opus model ids.
Names in the bundleclaude-opus-5-5
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on API usage primer for Claude touched a line naming claude-opus-5-5 after this was published.
* Claude Opus 5.5 (`claude-opus-5-5`, adaptive thinking only, always on)claude_api_primer see the edit
Confirmed since
Anthropic's documentation has since written up claude-opus-5-5, on claude-api-skill.
When the scope is ambiguous (for example, a bare `/claude-api migrate to claude-opus-5-5`), the skill asks you to choose between the entire working directory, a specific subdirectory, or an explicit file list before editing any files. This…agents-and-tools/agent-skills/claude-api-skill see the edit
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up claude-opus-5-5, on claude-api-skill.
Anthropic's release notes agree
Added Claude Opus 5.5 (claude-opus-5-5), now the default Opus model — 1M context, $4/$20 per Mtok with $0.20/Mtok cache reads