## Store your API key securely Create a file outside your /etc/nixos directory to store your Cloudflare API token: ```bash sudo mkdir -p /var/secrets sudo nano /var/secrets/cloudflare-token sudo chmod 600 /var/secrets/cloudflare-token sudo chown root:root /var/secrets/cloudflare-token ``` This token is shared by both `cloudflare-ddns.nix` (DDNS updates) and `nginx.nix` (ACME wildcard cert via DNS-01 challenge). ## Get your Cloudflare API Token Go to Cloudflare Dashboard → My Profile → API Tokens and create a token with: - **Zone : Zone : Read** - **Zone : DNS : Edit** Both permissions are required — Zone:Read for ACME to locate the zone, DNS:Edit for DDNS updates and ACME challenge TXT records. Copy the token to `/var/secrets/cloudflare-token`.