Rate limiting headers (#24967)

Author: dcpena

src/content/docs/fundamentals/api/reference/limits.mdx

@@ -8,3 +8,14 @@ sidebar:
 import { Render } from "~/components";
 
 <Render file="api-rate-limits" product="fundamentals"  params={{showHeading: true}} />
+
+## Rate limiting headers
+
+The following headers are returned when calling REST APIs:
+
+- `x-ratelimit-limit`: The total number of requests a caller can make.
+- `x-ratelimit-remaining`: The number of remaining requests before the rate limit takes effect.
+- `retry-after`: The number of seconds, rounded up, until more capacity is available.
+- `x-ratelimit-reset`: The `RFC 1123` formatted date when more capacity is available.
+
+Cloudflare's SDKs will also automatically work with the headers and back off in response to rate limits.