Custom domains on DevStack hosting (beta)

Status: implemented, ship-dark — CUSTOM_DOMAINS_ENABLED=false and SERVER_BINDINGS_ENABLED=false in wrangler.jsonc until the 100–200 domain pilot is verified. Capacity plan: ../operations/CUSTOM-DOMAINS-CAPACITY-200.md.

Prerequisites#

1. A production DevStack hosting deployment (*.devstack.bid live URL).
2. The custom hostname's DNS zone on Cloudflare in the platform account (Workers Custom Domain + edge certificate).
3. Platform secrets: SITES_CF_API_TOKEN (Workers Scripts: Edit), SITES_CF_ACCOUNT_ID, SITES_DISPATCH_NAMESPACE, SITES_PROXY_SECRET, R2 SITES.

Flow#

1. User adds app.example.com on the project page or POST /api/projects/:id/domains.
2. User creates TXT _devstack-challenge.app.example.com = verify token (shown in API/UI).
3. POST /api/projects/:id/domains/:domainId/verify checks TXT (public DNS), attaches Workers Custom Domain to devstack-sites, writes custom-hosts/app.example.com.json in R2 pointing at the current production deployment (and server Worker if SSR).
4. Promote / rollback / SSR production deploy calls syncActiveCustomDomains so all active domains track the new deployment.

Limits#

• Max 5 custom domains per project.
• Hostnames must not be under *.devstack.bid (use the free subdomain instead).
• Preview URLs remain *.devstack.bid only.

Server bindings (SSR)#

PUT /api/projects/:id/server-bindings with { "ai": true } adds a Workers AI binding on the next OpenNext upload. No platform D1/R2 bindings. Redeploy production to apply.

Cost#

No extra DevStack SKU in this beta. User pays their domain registrar; Cloudflare zone/Workers usage stays on the platform account (owner-approved spend). Customer-specific Cloudflare deploy (target=cloudflare) is unchanged — attach custom domains in their own dashboard.