Custom domain support for Sanity API endpoints for white labeling

Great question! I appreciate your enthusiasm for Sanity, and I understand the need for white-label solutions in enterprise contexts.

Unfortunately, custom domains for the Sanity API endpoints ({id}.api.sanity.io) are not currently available as a standard feature, even on Enterprise plans. The SSL certificate mismatch you're encountering when trying to use a CNAME is expected behavior since the certificates are issued for the *.api.sanity.io domain pattern.

However, there are a few things worth noting:

Current Enterprise Options:

• Sanity's Enterprise plans do include dedicated infrastructure with some customization options
• Custom domains are available for the CDN/asset delivery (your images and files)
• Based on their documentation, they note: "We provide dedicated infrastructure (including custom domains) on enterprise level plans" - though this primarily refers to asset delivery rather than API endpoints

Potential Workarounds:

1. Proxy approach: You could set up your own API proxy/gateway that forwards requests to Sanity's API while serving from your custom domain. This adds a layer but gives you the white-label appearance you need.

2. Contact Sales: Since custom API domains might be available as part of custom Enterprise agreements, I'd recommend reaching out to Sanity's sales team to discuss your specific white-label requirements. They may have solutions for enterprise customers that aren't publicly documented.

Why This Matters:

For true white-label solutions, having custom domains across all touchpoints (including API endpoints) is important for brand consistency and client trust. This is a reasonable feature request, and Sanity's team is generally responsive to enterprise needs.

I'd suggest submitting this as a feature request through their community Slack or directly to your account team if you're already on an Enterprise plan. The more they hear about this use case, the more likely it could be prioritized!