Claude Code Adds /claude-api api-version to Migrate Your Claude API Code

Claude CodeOct 21, 2026View original changelog

Claude Code's bundled /claude-api skill gained an api-version subcommand that moves code calling the Claude API up to API version 2026-10-21. Instead of hunting through a codebase for calls pinned to an older version, you run one command and let Claude Code perform the migration.

Key Takeaways

/claude-api api-version is a new subcommand of Claude Code's bundled /claude-api skill.
It migrates Claude API code to API version 2026-10-21 in one invocation.
It removes the manual work of finding every pinned call site and looking up what changed between versions.
The same release fixed bundled-skill descriptions in /help and the / menu, making the command easier to find.
Shipped in Claude Code 2.1.307, published 2026-10-21.

One Command to Move to a New API Version

Claude Code ships a bundled skill called /claude-api that helps with work against the Claude API. Release 2.1.307 adds a new subcommand to it: /claude-api api-version, which moves Claude API code to API version 2026-10-21.

Why This Is Useful

API version bumps are the kind of chore that is easy to postpone. The calls are usually scattered across a codebase, each one may pin a version string, and the changes between versions are the sort of detail you have to look up rather than remember. Running a single slash command and having Claude Code locate and update the affected code removes most of that friction.

Fits an Existing Pattern

This is the same shape as other task-focused commands Claude Code has been adding — a narrow, named operation you invoke directly rather than describing in a prompt each time. The surrounding release also fixed /help and the / command menu showing long model-facing descriptions for bundled skills such as /claude-api instead of their short ones, so the command is easier to discover in the menu than it would have been a release earlier.

Who It Is For

Anyone building on the Claude API from a codebase that Claude Code can see. If your project pins an older API version, this is the fastest path to 2026-10-21.