---
title: Preview transformer
---

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

[Logpush](https://developers.cloudflare.com/api/resources/logpush)

[Transformers](https://developers.cloudflare.com/api/resources/logpush/subresources/transformers)

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# Preview transformer

POST/accounts/{account\_id}/logpush/transformers/preview

Executes a SQL transformer against a single input record and returns the transformed output. This is a stateless endpoint — nothing is persisted.

##### 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)

`Logs Write`

##### Path ParametersExpand Collapse 

account\_id: string

Identifier.

maxLength32

##### Body ParametersJSONExpand Collapse 

input: map\[unknown\]

A single log record to transform (JSON object).

sql: string

The SQL transformer query. Maximum 32 KB. The query must contain a FROM clause referencing a valid logpush dataset.

maxLength32768

##### ReturnsExpand Collapse 

errors: array of object { code, message, documentation\_url, source } 

code: number

minimum1000

message: string

documentation\_url: optional string

source: optional object { pointer } 

pointer: optional string

messages: array of object { code, message, documentation\_url, source } 

code: number

minimum1000

message: string

documentation\_url: optional string

source: optional object { pointer } 

pointer: optional string

success: true

Whether the API call was successful.

result: optional array of map\[unknown\]

An array of transformed log records. Queries that produce multiple rows from a single input (e.g. via UNNEST) return one object per output row. Null if the query filtered out the input record.

### Preview transformer

HTTP

HTTPHTTP

TypeScriptTypeScript

PythonPython

GoGo

TerraformTerraform

```
curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/logpush/transformers/preview \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
    -d '{
          "input": {
            "ClientIP": "bar",
            "ClientRequestHost": "bar",
            "EdgeStartTimestamp": "bar",
            "RayID": "bar"
          },
          "sql": "SELECT ClientIP, RayID FROM http_requests"
        }'
```

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"
      }
    }
  ],
  "success": true,
  "result": [
    {
      "ClientIP": "bar",
      "RayID": "bar"
    }
  ]
}
```

##### 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"
      }
    }
  ],
  "success": true,
  "result": [
    {
      "ClientIP": "bar",
      "RayID": "bar"
    }
  ]
}
```