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Configure Schema Validation

Schema Validation 2.0 allows all corresponding configuration calls to be made via API. This validation centers more around individual endpoints and lets you set mitigation actions for each endpoint individually. Additionally, you can use Cloudflare-provided learned schemas that we learn automatically from your traffic for individual endpoints.

Upload schemas via the API to Schema Validation

  1. Upload a schema.
  2. Ensure that your endpoints are added in Endpoint Management.
  3. Set the schema to active if it is not already done.
  4. Set the Schema Validation zone-wide action from none to log.
  5. Send test traffic that violates the schema.
  6. View test traffic in Security Events by filtering for Service > API Shield - Schema Validation.
  7. Optional:
    • Set a single endpoint to block.
    • Set the Schema Validation zone-wide to block.
    • Temporarily override all schemas zone-wide to none.
    • Remove the temporary override.

Cloudflare recommends you to rerun test traffic and monitor the HTTP response codes after changing any settings to ensure Schema Validation is operating as expected.

Settings changes may take a few minutes to implement.

Configuration

Upload and activate a schema

Upload a schema via the v4 API using POST. This example requires a example_schema.yaml schema file in the current folder.

cURL command
curl --request POST "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas" \
--header "Authorization: Bearer <API_TOKEN>" \
--form file=@example_schema.yaml --form kind=openapi_v3 --form name=example_schema --form validation_enabled=false
Result
{
"result":
{
"schema":
{
"schema_id": "af632e95-c986-4738-a67d-2ac09995017a",
"name": "example_schema",
"kind": "openapi_v3",
"source": "<SOURCE>",
"created_at": "2023-04-03T15:10:08.902309Z"
}
},
"success": true,
"errors":
[],
"messages":
[]
}

By default, Schema Validation is disabled for an uploaded schema so that you can inspect it first. You can upload a schema and enable it immediately by setting the form parameter validation_enabled=true.

Use a PATCH request to activate a schema after inspection.

cURL command
curl --request PATCH "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas/{schema_id}" \
--header "Authorization: Bearer <API_TOKEN>" \
--header 'Content-Type: application/json' \
--data '{
"validation_enabled": true
}'
Result
{
"result":
{
"schema_id": "0bf58160-5da3-48ac-80a9-069f9642c1a0",
"name": "api_schema.json",
"kind": "openapi_v3",
"validation_enabled": true,
"created_at": "0001-01-01T00:00:00Z"
},
"success": true,
"errors":
[],
"messages":
[]
}

When a schema is active, it executes the mitigation action specified for each operation. Refer to change the default and operation-specific mitigation action.

Add new operations to Endpoint Management

Schemas contain a set of servers, paths, and methods, which together define an operation. Schema Validation only acts on the requests to operations which have been added to the API Shield Endpoint Management. If a schema contains operations which have not been added to Endpoint Management, they can be retrieved together with the configuration information about added operations.

cURL command
curl --request GET "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas/{schema_id}/operations?feature=schema_info&operation_status=new&page=1&per_page=5000" \
--header "Authorization: Bearer <API_TOKEN>" \
--header 'Content-Type: application/json'
Result
{
"result":
[
{
"method": "GET",
"host": "example.com",
"endpoint": "/pets"
}
],
"success": true,
"errors": [],
"messages": [],
"result_info": {
"page": 1,
"per_page": 30,
"count": 1,
"total_count": 1
}
}

To receive information about the configuration of existing operations, Cloudflare recommends passing the ?feature=schema_info parameter.

You can add new operations in a schema to Endpoint Management using POST.

cURL command
curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations" \
--header "Authorization: Bearer <API_TOKEN>" \
--header 'Content-Type: application/json' \
--data '[
{
"method": "GET",
"host": "example.com",
"endpoint": "/pets",
}
]'
Result
{
"result": [
{
"operation_id": "6c734fcd-455d-4040-9eaa-dbb3830526ae",
"method": "GET",
"host": "example.com",
"endpoint": "/pets",
"last_updated": "2023-04-04T16:07:37.575971Z"
}
],
"success": true,
"errors":
[],
"messages":
[]
}

You can add all operations in a schema that do not already exist in Endpoint Management by combining two commands as one. There is a maximum of 20 operations for this API call. The example requires the jq tool.

cURL command
curl --silent "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations" \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data "$(curl --silent "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas/{schema_id}/operations?feature=schema_info&page=1&per_page=5000" --header "Authorization: Bearer <API_TOKEN>" | jq ".result")"

Change the default and operation-specific mitigation action

If a schema is uploaded and active for a set of operations, it validates incoming requests to each operation and decides whether a mitigation action should be taken. This mitigation action is defined per operation and can take the values none, log, and block, which correspond to no action, logging the requests, or blocking them before they reach the origin.

New operations will not have a mitigation action set and will use the zone-wide default mitigation action. The current default mitigation action can be retrieved using GET.

cURL command
curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/settings/schema_validation" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result": {
"validation_default_mitigation_action": "none",
"validation_override_mitigation_action": null
}
"success": true,
"errors":
[],
"messages":
[]
}

A new value out of none, log, and block can be set using PUT.

cURL command
curl --request PUT "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/settings/schema_validation" \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
"validation_default_mitigation_action": "block"
}'
Result
{
"result": {
"validation_default_mitigation_action": "block",
"validation_override_mitigation_action": null
}
"success": true,
"errors":
[],
"messages":
[]
}

If the mitigation action for an individual operation is of interest, the current value can be retrieved with GET using the operation ID.

cURL command
curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations/{operation_id}/schema_validation" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result": {
"mitigation_action": "null"
}
"success": true,
"errors":
[],
"messages":
[]
}

If the value is null, it means that no mitigation action has been specified for this operation and the default mitigation action is being used.

You can set the mitigation action to a value out of none, block, log, and null by using PUT.

cURL command
curl --request PUT "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations/{operation_id}/schema_validation" \
--header "Authorization: Bearer <API_TOKEN>" \
--header "Content-Type: application/json" \
--data '{
"mitigation_action": "block"
}'
Result
{
"result": {
"mitigation_action": "block"
}
"success": true,
"errors":
[],
"messages":
[]
}

List all schemas

You can get an overview of the schemas currently active on a zone using GET.

validation_enabled=true is an optional parameter.

cURL command
curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas?omit_source=true" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result": [
{
"schema_id": "af632e95-c986-4738-a67d-2ac09995017a",
"name": "example_schema",
"kind": "openapi_v3",
"source": "<SOURCE>",
"created_at": "2023-04-03T15:10:08.902309Z"
}
]
"success": true,
"errors":
[],
"messages":
[]
}

Delete a schema

You can delete a schema using DELETE.

cURL command
curl --request DELETE "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/user_schemas/{schema_id}" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result": null,
"success": true,
"errors":
[],
"messages":
[]
}

Activate a learned schema for an operation

Cloudflare provides automatically learned parameter schemas for all operations in Endpoint Management with a sufficient amount of requests. A learned schema can be inspected using GET.

cURL command
curl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations/{operation_id}?feature=parameter_schemas" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result":
{
"operation_id": "5c734fcd-455d-4040-9eaa-dbb3830526ae",
"method": "PATCH",
"host": "example.com",
"endpoint": "/pets",
"last_updated": "2023-04-04T16:07:37.575971Z",
"features":
{
"parameter_schemas":
{
"last_updated": "2023-04-03T20:11:55.879006Z",
"parameter_schemas":
{
"responses": null,
"parameters":
[
{
"in": "query",
"name": "var1",
"schema":
{
"type": "string"
},
"required": true,
"description": "Sufficient requests have been observed for this parameter to provide high confidence in this parameter schema."
}
],
"x-cf-parameter-schemas": "operation schema with automatically learned path and query parameters"
}
}
}
},
"success": true,
"errors":
[],
"messages":
[]
}

If you are satisfied with the inspected parameter schema, you can add and activate it using PUT.

cURL command
curl --request PUT "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/operations/{operation_id}/cloudflare_learned_schema?timestamp=2023-04-03T20:11:55.879006Z" \
--header "Authorization: Bearer <API_TOKEN>"
Result
{
"result": null,
"success": true,
"errors":
[],
"messages":
[]
}

Disable Schema Validation

To quickly disable schema validation for a whole zone, use PATCH. This operation will override all operation-mitigation actions.

cURL command
curl --request PATCH "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/settings/schema_validation" \
--header "Authorization: Bearer <API_TOKEN>" \
--header 'Content-Type: application/json' \
--data '{
"validation_override_mitigation_action": "none"
}'
Result
{
"result": {
"validation_default_mitigation_action": "block",
"validation_override_mitigation_action": "none"
}
"success": true,
"errors":
[],
"messages":
[]
}