Early Hints for SaaS

Early Hints allows the browser to begin loading resources while the origin server is compiling the full response. This improves webpage’s loading speed for the end user. As a SaaS provider, you may prioritize speed for some of your custom hostnames. Using custom metadata, you can enable Early Hints per custom hostname.

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Prerequisites

Before you can employ Early Hints for SaaS, you need to create a custom hostname. Review Get Started with Cloudflare for SaaS if you have not already done so.

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Enable Early Hints per custom hostname via the API

1. Locate your zone ID, available in the Cloudflare dashboard.

2. Locate your Authentication Key by selecting My Profile > API tokens > Global API Key.

3. If you are creating a new custom hostname, make an API call such as the example below, specifying "early_hints": "on":

curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/custom_hostnames" \
--header "X-Auth-Email: <EMAIL>" \
--header "X-Auth-Key: <API_KEY>" \
--header "Content-Type: application/json" \
--data '{
  "hostname": "{hostname}",
  "ssl": {
    "method": "http",
    "type": "dv",
    "settings": {
      "http2": "on",
      "min_tls_version": "1.2",
      "tls_1_3": "on",
      "early_hints": "on"
    },
    "bundle_method": "ubiquitous",
    "wildcard": false
  }
}'

4. For an existing custom hostname, locate the id of that hostname via a GET call:

curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/custom_hostnames?hostname={hostname}" \
--header "X-Auth-Email: <EMAIL>" \
--header "X-Auth-Key: <API_KEY>"

5. Then make an API call such as the example below, specifying "early_hints": "on":

curl --request PATCH \
"https://api.cloudflare.com/client/v4/zones/{zone_id}/custom_hostnames/{id}" \
--header "X-Auth-Email: <EMAIL>" \
--header "X-Auth-Key: <API_KEY>" \
--header "Content-Type: application/json" \
--data '{
  "ssl": {
    "method": "http",
    "type": "dv",
    "settings": {
      "http2": "on", // Note: These settings will be set to default if not included when updating early hints
      "min_tls_version": "1.2",
      "tls_1_3": "on",
      "early_hints": "on"
    }
  }
}'

Currently, all options within settings are required in order to prevent those options from being set to default. You can pull the current settings state prior to updating Early Hints by leveraging the output that returns the id for the hostname.