Expression validation

The Cloudflare Filters API supports an endpoint for validating expressions.

​Examples

​Validate expression via query string

​Request

curl -X GET -H "X-Auth-Email: user@cloudflare.com" -H "X-Auth-Key: REDACTED" 'https://api.cloudflare.com/client/v4/filters/validate-expr?expression=ip.src==34'

​Response

{  "result": null,  "success": false,  "errors": [    {      "message": "Filter parsing error:\n`ip.src==34`\n          ^^ couldn't parse address in network: invalid IP address syntax\n"    }  ],  "messages": null}

Note the validation error in the response. In this example, the error is due to an invalid IP address format:

Filter parsing error:`ip.src==34`          ^^ couldn't parse address in network: invalid IP address syntax

​Validate expression via JSON object

​Request

curl -X POST \    -H "X-Auth-Email: user@cloudflare.com" \    -H "X-Auth-Key: REDACTED" \     -H "Content-Type: application/json" \     -d '{    "expression": "ip.src in {2400:cb00::/32 2405:8100::/2000 2405:b500::/32 2606:4700::/32 2803:f800::/32 2c0f:f248::/32 2a06:98c0::/29}"}' "https://api.cloudflare.com/client/v4/filters/validate-expr"

​Response

{  "result": null,  "success": false,  "errors": [    {      "message": "Filter parsing error:\n`ip.src in {2400:cb00::/32 2405:8100::/2000 2405:b500::/32 2606:4700::/32 2803:f800::/32 2c0f:f248::/32 2a06:98c0::/29}`\n                                        ^^^^ number too large to fit in target type while parsing with radix 10\n"    }  ],  "messages": null}

Note the validation error in the response. In this example, the value for the subnet mask, /2000, is not a valid IPv6 CIDR mask:

Filter parsing error:`ip.src in {2400:cb00::/32 2405:8100::/2000 2405:b500::/32 2606:4700::/32 2803:f800::/32 2c0f:f248::/32 2a06:98c0::/29}`                                        ^^^^ number too large to fit in target type while parsing with radix 10