{"version":"2.0.58","anchor":"custom-api-beta-headers-betas","canonical_anchor":"custom-api-beta-headers-betas","heading":"Custom API Beta Headers ( --betas )","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.0.58\/e\/custom-api-beta-headers-betas","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.0.58","markdown":"### Custom API Beta Headers (`--betas`)\n\n**What:** API key users can now specify custom beta headers to include in API requests via a new CLI option.\n\n**How to use:**\n\n`claude --betas context-1m-2025-08-07` **Details:**\n\n- Only available for API key authentication (not web\/OAuth)\n- Currently only `context-1m-2025-08-07` is in the allowlist\n- Invalid betas trigger warnings but don't fail execution\n- **Evidence**: `wn0()` at line 67682, `$n0` allowlist at line 67714, CLI option at line 526721 in v2.0.58"}