Source Intelligence
Follow Discord

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

← All of v2.0.58 Home All releases ←olderv2.0.57 v2.0.59newer→
Claude Code v2.0.58

Custom API Beta Headers (--betas)

What: API key users can now specify custom beta headers to include in API requests via a new CLI option.

How to use:

claude --betas context-1m-2025-08-07

Details:

  • Only available for API key authentication (not web/OAuth)
  • Currently only context-1m-2025-08-07 is in the allowlist
  • Invalid betas trigger warnings but don't fail execution
  • Evidence: wn0() at line 67682, $n0 allowlist at line 67714, CLI option at line 526721 in v2.0.58

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.0.58 →