---
title: Preview transformer
---
[Skip to content](#_top)
[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)
Copy Markdown
Open in **Claude**Open in **ChatGPT**Open in **Cursor**
---
**Copy Markdown****View as Markdown**
# 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.
**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`
##### P ath ParametersExpand Collapse
account\_id: string
Identifier.
maxLength32
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(params)%20default%20%3E%20(param)%20account_id%20%3E%20(schema)>)
##### Body ParametersJSONExpand Collapse
input: map\[unknown]
A single log record to transform (JSON object).
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(params)%200%20%3E%20(param)%20input%20%3E%20(schema)>)
sql: string
The SQL transformer query. Maximum 32 KB. The query must contain a FROM clause referencing a valid logpush dataset.
maxLength32768
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(params)%200%20%3E%20(param)%20sql%20%3E%20(schema)>)
##### ReturnsExpand Collapse
errors: array of object {code, message, documentation\_url, source }
code: number
minimum1000
Link to this property
message: string
Link to this property
documentation\_url: optional string
Link to this property
source: optional object {pointer }
pointer: optional string
Link to this property
Link to this property
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(network%20schema)%20%3E%20(property)%20errors>)
messages: array of object {code, message, documentation\_url, source }
code: number
minimum1000
Link to this property
message: string
Link to this property
documentation\_url: optional string
Link to this property
source: optional object {pointer }
pointer: optional string
Link to this property
Link to this property
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(network%20schema)%20%3E%20(property)%20messages>)
success: true
Whether the API call was successful.
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(network%20schema)%20%3E%20(property)%20success>)
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.
[Link to this property](<#(resource)%20logpush.transformers%20%3E%20(method)%20preview%20%3E%20(network%20schema)%20%3E%20(property)%20result>)
### Preview transformer
HTTP
HTTPTypeScriptPythonGoTerraform
```
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"
}
]
}
```