Create rate limiting rules via API

Use the Rulesets API to create a rate limiting rule via API.

A rate limiting rule is similar to a regular rule handled by the Ruleset Engine, but contains an additional ratelimit field with the rate limiting configuration. Refer to Rate limiting parameters for more information on this field and its parameters.

You must deploy rate limiting rules to the http_ratelimit phase.

​​ Create a rate limiting rule

To create a rate limiting rule, add a rule with a ratelimit field to the http_ratelimit phase entry point ruleset by issuing a PUT request (refer to the examples below).

Add any existing rules in the ruleset to the request by including their rule ID in the rules field of the request body. Rate limiting rules must appear at the end of the rules list.

​​ Example A - Rate limiting based on request properties

This example defines a rate limiting rule based on three characteristics applied to URL paths starting with /api/ and with action block.

Request
curl -X PUT \
"https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/rulesets/phases/http_ratelimit/entrypoint" \
-H "Authorization: Bearer <API_TOKEN>" \
-H "Content-Type: application/json" \
-d '{
  "rules": [
    {
      "description": "My rate limiting rule",
      "expression": "(http.request.uri.path matches \"^/api/\")",
      "action": "block",
      "ratelimit": {
        "characteristics": [
          "cf.colo.id",
          "ip.src",
          "http.request.headers[\"x-api-key\"]"
        ],
        "period": 60,
        "requests_per_period": 100,
        "mitigation_timeout": 600
      }
    }
  ]
}'

​​ Example B - Rate limiting with a custom response

This example request defines a custom plain text response for requests blocked due to rate limiting.

Request
curl -X PUT \
"https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/rulesets/phases/http_ratelimit/entrypoint" \
-H "Authorization: Bearer <API_TOKEN>" \
-H "Content-Type: application/json" \
-d '{
  "rules": [
    {
      "description": "My rate limiting rule",
      "expression": "(http.request.uri.path matches \"^/api/\")",
      "action": "block",
      "action_parameters": {
        "response": {
          "status_code": 403,
          "content": "You have been rate limited.",
          "content_type": "text/plain"
        }
      },
      "ratelimit": {
        "characteristics": [
          "cf.colo.id",
          "ip.src",
          "http.request.headers[\"x-api-key\"]"
        ],
        "period": 60,
        "requests_per_period": 100,
        "mitigation_timeout": 600
      }
    }
  ]
}'

​​ Example C - Rate limiting ignoring cached assets

This example request creates a rate limiting rule that does not consider requests for cached assets when calculating the rate.

Request
curl -X PUT \
"https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/rulesets/phases/http_ratelimit/entrypoint" \
-H "Authorization: Bearer <API_TOKEN>" \
-H "Content-Type: application/json" \
-d '{
  "rules": [
    {
      "description": "My rate limiting rule",
      "expression": "(http.request.uri.path matches \"^/api/\")",
      "action": "block",
      "ratelimit": {
        "characteristics": [
          "cf.colo.id",
          "ip.src",
          "http.request.headers[\"x-api-key\"]"
        ],
        "period": 60,
        "requests_per_period": 100,
        "mitigation_timeout": 600,
        "requests_to_origin": true
      }
    }
  ]
}'

​​ Example D - Complexity-based rate limiting rule

This example configures a complexity-based rate limiting rule that takes the my-score HTTP response header into account to calculate a total complexity score for the client. The counter with the total score is updated when there is a match for the rate limiting rule’s counting expression (in this case, the same as the rule expression). When this total score becomes larger than 400 during a 60-second period, any later client requests will be blocked for a period of 600 seconds (10 minutes).

Request
curl -X PUT \
"https://api.cloudflare.com/client/v4/zones/<ZONE_ID>/rulesets/phases/http_ratelimit/entrypoint" \
-H "Authorization: Bearer <API_TOKEN>" \
-H "Content-Type: application/json" \
-d '{
  "rules": [
    {
      "description": "My complexity-based rate limiting rule",
      "expression": "http.request.uri.path matches \"^/graphql/\"",
      "action": "block",
      "ratelimit": {
        "characteristics": [
          "cf.colo.id",
          "http.request.headers[\"x-api-key\"]"
        ],
        "period": 60,
        "score_per_period": 400,
        "score_response_header_name": "my-score",
        "mitigation_timeout": 600,
        "counting_expression": ""
      }
    }
  ]
}'