{"version":"2.1.277","anchor":"custom-llm-gateway-provider-headers-validated-for-safety","canonical_anchor":"custom-llm-gateway-provider-headers-validated-for-safety","heading":"Custom LLM gateway provider headers validated for safety","tier":"notice","area":"Elsewhere","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.277\/e\/custom-llm-gateway-provider-headers-validated-for-safety","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.277","markdown":"### Custom LLM gateway provider headers validated for safety\n\nCustom LLM gateway header settings are now validated for valid names, no duplicates, and no collisions with reserved headers\n\n**What**\n\nIf you configure a custom `anthropic` provider (an LLM gateway) with custom HTTP headers in settings, Claude Code now checks that configuration more strictly:\n\n- Header names must be valid HTTP header names\n\n- The same header name can't appear twice, even with different capitalization\n\n- Header names can't collide with reserved headers that the gateway or the provider's own SDK already sets or signs\n\n- Header values must be non-empty, printable ASCII text with surrounding whitespace trimmed\n\n**Why**\n\nThis catches misconfigured or conflicting custom headers before they cause confusing request failures, and prevents a user-supplied header from accidentally overriding one the gateway relies on for authentication or signing.\n\n- Area: Elsewhere\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5"}