---
title: Update a Content Scanning custom expression for a zone.
---

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[API Reference](https://developers.cloudflare.com/api)

[Content Scanning](https://developers.cloudflare.com/api/resources/content%5Fscanning)

[Payloads](https://developers.cloudflare.com/api/resources/content%5Fscanning/subresources/payloads)

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# Update a Content Scanning custom expression for a zone.

PATCH/zones/{zone\_id}/content-upload-scan/payloads/{expression\_id}

Update the Content Scanning custom expression with the given identifier and return the updated list of expressions.

##### Security

API Token

The preferred authorization scheme for interacting with the Cloudflare API. [Create a token](https://developers.cloudflare.com/fundamentals/api/get-started/create-token/).

**Example:**`Authorization: Bearer Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY`

API Email + API Key

The previous authorization scheme for interacting with the Cloudflare API, used in conjunction with a Global API key.

**Example:**`X-Auth-Email: user@example.com`

The previous authorization scheme for interacting with the Cloudflare API. When possible, use API tokens instead of Global API keys.

**Example:**`X-Auth-Key: 144c9defac04969c7bfad8efaa8ea194`

##### Accepted Permissions (at least one required)

`Zone WAF Write` `Account WAF Write`

##### Path ParametersExpand Collapse 

zone\_id: string

Defines an identifier.

maxLength32

expression\_id: string

Defines the unique ID for this Content Scanning custom expression.

maxLength32

##### Body ParametersJSONExpand Collapse 

payload: string

Defines the custom content extraction expression used to reach content objects in the request.

##### ReturnsExpand Collapse 

errors: array of [ResponseInfo](https://developers.cloudflare.com/api/resources/$shared#%28resource%29%20%24shared%20%3E%20%28model%29%20response%5Finfo%20%3E%20%28schema%29) { code, message, documentation\_url, source } 

code: number

minimum1000

message: string

documentation\_url: optional string

source: optional object { pointer } 

pointer: optional string

messages: array of [ResponseInfo](https://developers.cloudflare.com/api/resources/$shared#%28resource%29%20%24shared%20%3E%20%28model%29%20response%5Finfo%20%3E%20%28schema%29) { code, message, documentation\_url, source } 

code: number

minimum1000

message: string

documentation\_url: optional string

source: optional object { pointer } 

pointer: optional string

result: array of object { id, payload } 

id: optional string

Defines the unique ID for this Content Scanning custom expression.

maxLength32

payload: optional string

Defines the custom content extraction expression used to reach content objects in the request.

success: true

Whether the API call was successful.

### Update a Content Scanning custom expression for a zone.

HTTP

HTTPHTTP

TypeScriptTypeScript

PythonPython

GoGo

TerraformTerraform

```
curl https://api.cloudflare.com/client/v4/zones/$ZONE_ID/content-upload-scan/payloads/$EXPRESSION_ID \
    -X PATCH \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
    -d '{
          "payload": "lookup_json_string(http.request.body.raw, \\"file\\")"
        }'
```

200 example

```
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "result": [
    {
      "id": "a350a054caa840c9becd89c3b4f0195b",
      "payload": "lookup_json_string(http.request.body.raw, \"file\")"
    }
  ],
  "success": true
}
```

##### Returns Examples

200 example

```
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "result": [
    {
      "id": "a350a054caa840c9becd89c3b4f0195b",
      "payload": "lookup_json_string(http.request.body.raw, \"file\")"
    }
  ],
  "success": true
}
```