> This page is for version 2025-09-18 (default).
> For other versions, use one of these documentation indexes:
> - 2025-09-18 (default): https://apidocs.polytomic.com/2025-09-18/llms.txt
> - 2024-02-08: https://apidocs.polytomic.com/2024-02-08/llms.txt
> - 2023-04-25: https://apidocs.polytomic.com/2023-04-25/llms.txt
> - 2022-12-12: https://apidocs.polytomic.com/2022-12-12/llms.txt
> - 2021-05-23: https://apidocs.polytomic.com/2021-05-23/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://apidocs.polytomic.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://apidocs.polytomic.com/_mcp/server.

# Upsert Schema Fields

POST https://app.polytomic.com/api/connections/{connection_id}/schemas/{schema_id}/fields
Content-Type: application/json

Creates or updates user-defined fields on a schema, matched by field_id.

Fields are matched by `field_id`. Reusing an existing `field_id` updates that
field; using a new `field_id` creates a new user-defined field.

This makes the endpoint safe to retry when you are intentionally upserting the
same field definitions. It is not a patch-by-position operation.

If some fields succeed and others fail, the endpoint can return a partial
success response. Validate the response status and message rather than assuming
the whole batch was applied uniformly.

Reference: https://apidocs.polytomic.com/api-reference/schemas/upsert-field

## Authentication

- `Authorization` header (bearer token, required) — Bearer user API key
- `Authorization` header (basic auth, required) — Basic organization-scoped API key

## Request

### Path parameters

- `connection_id` (string, required) — Unique identifier of the connection.
- `schema_id` (string, required) — Identifier of the schema the fields belong to.

### Body (application/json)

This endpoint expects an UpsertSchemaFieldRequest.

- `fields` (list of UserFieldRequest, optional, nullable) — Fields to create or update on the schema. Existing user-defined fields with the same field_id are replaced.

## Response

### 202

Accepted

## Errors

### 400 Bad Request Error

Bad Request

- `key` (string, optional)
- `message` (string, optional)
- `metadata` (map from string to any, optional)
- `status` (integer, optional)

### 404 Not Found Error

Not Found

- `key` (string, optional)
- `message` (string, optional)
- `metadata` (map from string to any, optional)
- `status` (integer, optional)

### 500 Internal Server Error

Internal Server Error

- `key` (string, optional)
- `message` (string, optional)
- `metadata` (map from string to any, optional)
- `status` (integer, optional)

## Types

### UserFieldRequest

- `field_id` (string, required) — Stable identifier for the user-defined field. Reuse an existing field_id to update a field in place.
- `label` (string, required) — Human-readable label shown to users selecting this field in the app.
- `type` (string, required) — One of: string, number, boolean, datetime, array, object, binary.
- `definition` (TypesDefinition, optional) — Detailed field type: a type name such as "bigint", or an array naming a complex type followed by its details, such as \["decimal", \{"precision": 10, "scale": 2}] or \["array", "string"].
- `example` (any, optional) — Example value shown in the UI and used as a hint for downstream consumers.
- `path` (string, optional, nullable) — JSON path expression that extracts the field's value from the source record. Required for nested or computed fields; omit for top-level fields.

### TypesDefinition

Detailed field type: a type name such as "bigint", or an array naming a complex type followed by its details, such as \["decimal", \{"precision": 10, "scale": 2}] or \["array", "string"].

## Examples

**Request**

```json
{}
```

**Response**

```json
{}
```

**SDK Code**

```python
import requests

url = "https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields"

payload = {}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields"

	payload := strings.NewReader("{}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields', [
  'body' => '{}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/schemas/public.users/fields")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```