Use the [Rulesets API](https://developers.cloudflare.com/ruleset-engine/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` object with the rate limiting configuration. Refer to [Rate limiting parameters](https://developers.cloudflare.com/waf/rate-limiting-rules/parameters/) for more information on this field and its parameters.

You must deploy rate limiting rules to the `http_ratelimit` [phase entry point ruleset](https://developers.cloudflare.com/ruleset-engine/about/rulesets/#entry-point-ruleset).

Rate limiting rules must appear at the end of the rules list.

## Create a rate limiting rule

To create a rate limiting rule for a zone, add a rule with a `ratelimit` object to the `http_ratelimit` phase entry point ruleset.

1. Invoke the [Get a zone entry point ruleset](https://developers.cloudflare.com/api/resources/rulesets/subresources/phases/methods/get/) operation to obtain the definition of the entry point ruleset for the `http_ratelimit` phase. You will need the [zone ID](https://developers.cloudflare.com/fundamentals/setup/find-account-and-zone-ids/) for this task.

2. If the entry point ruleset already exists (that is, if you received a `200 OK` status code and the ruleset definition), take note of the ruleset ID in the response. Then, invoke the [Create a zone ruleset rule](https://developers.cloudflare.com/api/resources/rulesets/subresources/rules/methods/create/) operation to add a rate limiting rule to the existing ruleset. Refer to the examples below for details.

3. If the entry point ruleset does not exist (that is, if you received a `404 Not Found` status code in step 1), create it using the [Create a zone ruleset](https://developers.cloudflare.com/api/resources/rulesets/methods/create/) operation. Include your rate limiting rule in the `rules` array. Refer to [Create ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/create/#example---create-a-zone-level-phase-entry-point-ruleset) for an example.

### Example A - Rate limiting based on request properties

This example adds a rate limiting rule to the `http_ratelimit` phase entry point ruleset for the zone with ID `{zone_id}`. The phase entry point ruleset already exists, with ID `{ruleset_id}`.

```bash
curl https://api.cloudflare.com/client/v4/zones/{zone_id}/rulesets/{ruleset_id}/rules \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "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
  }
}'
```

To define a specific position for the new rule, include a `position` object in the request body according to the guidelines in [Change the order of a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/update-rule/#change-the-order-of-a-rule-in-a-ruleset).

For instructions on creating an entry point ruleset and defining its rules using a single API call, refer to [Add rules to phase entry point rulesets](https://developers.cloudflare.com/ruleset-engine/basic-operations/add-rule-phase-rulesets/).

### Example B - Rate limiting with a custom response

This example adds a rate limiting rule to the `http_ratelimit` phase entry point ruleset for the zone with ID `{zone_id}`. The phase entry point ruleset already exists, with ID `{ruleset_id}`.

The new rule defines a [custom response](https://developers.cloudflare.com/waf/rate-limiting-rules/create-zone-dashboard/#configure-a-custom-response-for-blocked-requests) for requests blocked due to rate limiting.

```bash
curl https://api.cloudflare.com/client/v4/zones/{zone_id}/rulesets/{ruleset_id}/rules \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "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
  }
}'
```

To define a specific position for the new rule, include a `position` object in the request body according to the guidelines in [Change the order of a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/update-rule/#change-the-order-of-a-rule-in-a-ruleset).

For instructions on creating an entry point ruleset and defining its rules using a single API call, refer to [Add rules to phase entry point rulesets](https://developers.cloudflare.com/ruleset-engine/basic-operations/add-rule-phase-rulesets/).

### Example C - Rate limiting ignoring cached assets

This example adds a rate limiting rule to the `http_ratelimit` phase entry point ruleset for the zone with ID `{zone_id}`. The phase entry point ruleset already exists, with ID `{ruleset_id}`.

The new rule does not consider requests for cached assets when calculating the rate.

```bash
curl https://api.cloudflare.com/client/v4/zones/{zone_id}/rulesets/{ruleset_id}/rules \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "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
  }
}'
```

To define a specific position for the new rule, include a `position` object in the request body according to the guidelines in [Change the order of a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/update-rule/#change-the-order-of-a-rule-in-a-ruleset).

For instructions on creating an entry point ruleset and defining its rules using a single API call, refer to [Add rules to phase entry point rulesets](https://developers.cloudflare.com/ruleset-engine/basic-operations/add-rule-phase-rulesets/).

### Example D - Complexity-based rate limiting rule

Note

[Complexity-based rate limiting](https://developers.cloudflare.com/waf/rate-limiting-rules/request-rate/#complexity-based-rate-limiting) is available in beta and can only be configured via API.

This example adds a rate limiting rule to the `http_ratelimit` phase entry point ruleset for the zone with ID `{zone_id}`. The phase entry point ruleset already exists, with ID `{ruleset_id}`.

The new rule is 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).

```bash
curl https://api.cloudflare.com/client/v4/zones/{zone_id}/rulesets/{ruleset_id}/rules \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
  "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": ""
  }
}'
```

To define a specific position for the new rule, include a `position` object in the request body according to the guidelines in [Change the order of a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/update-rule/#change-the-order-of-a-rule-in-a-ruleset).

For instructions on creating an entry point ruleset and defining its rules using a single API call, refer to [Add rules to phase entry point rulesets](https://developers.cloudflare.com/ruleset-engine/basic-operations/add-rule-phase-rulesets/).

***

## Next steps

Use the different operations in the [Rulesets API](https://developers.cloudflare.com/ruleset-engine/rulesets-api/) to work with the rule you just created. The following table has a list of common tasks for working with rate limiting rules at the zone level:

| Task                      | Procedure                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| List all rules in ruleset | Use the [Get a zone entry point ruleset](https://developers.cloudflare.com/api/resources/rulesets/subresources/phases/methods/get/) operation with the `http_ratelimit` phase name to obtain the list of configured rate limiting rules and their IDs.For more information, refer to [View a specific ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/view/#view-a-specific-ruleset).                                                                                                                               |
| Update a rule             | Use the [Update a zone ruleset rule](https://developers.cloudflare.com/api/resources/rulesets/methods/update/) operation.You will need to provide the ruleset ID and the rule ID. To obtain these IDs, you can use the [Get a zone entry point ruleset](https://developers.cloudflare.com/api/resources/rulesets/subresources/phases/methods/get/) operation with the `http_ratelimit` phase name.For more information, refer to [Update a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/update-rule/). |
| Delete a rule             | Use the [Delete a zone ruleset rule](https://developers.cloudflare.com/api/resources/rulesets/methods/delete/) operation.You will need to provide the ruleset ID and the rule ID. To obtain these IDs, you can use the [Get a zone entry point ruleset](https://developers.cloudflare.com/api/resources/rulesets/subresources/phases/methods/get/) operation with the `http_ratelimit` phase name.For more information, refer to [Delete a rule in a ruleset](https://developers.cloudflare.com/ruleset-engine/rulesets-api/delete-rule/). |

These operations are covered in the Ruleset Engine documentation. The Ruleset Engine powers different Cloudflare products, including rate limiting rules.
