> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://apidocs.polytomic.com/2023-04-25/api-reference/connections/get-source-fields/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://apidocs.polytomic.com/_mcp/server.

# Connection Field Query

POST https://app.polytomic.com/api/connections/{id}/source/fields
Content-Type: application/json

Returns the source fields available on a connection for a given source configuration.

> 🚧 Deprecated
>
> Use `POST /api/connections/{id}/modelsync/source/fields` instead. Available in API version 2024-02-08 and later.

Reference: https://apidocs.polytomic.com/2023-04-25/api-reference/connections/get-source-fields

## Authentication

- `Authorization` header (basic auth, required) — This is the Polytomic deployment key (on-premises only)
- `Authorization` header (bearer token, required) — This is the Polytomic API key

## Request

### Path parameters

- `id` (string, required)

### Body (application/json)

This endpoint expects a V2ModelFieldsRequest.

- `query` (map from string to any, required, nullable)

## Response

### 200

OK

- `data` (list of V2ModelField, optional, nullable)

## Errors

### 400 Bad Request Error

Bad Request

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

### 401 Unauthorized Error

Unauthorized

- `code` (integer, optional) — Application-specific error code.
- `context` (map from string to any, optional) — Application context.
- `error` (string, optional) — Error message.
- `status` (string, optional) — Status text.

### 403 Forbidden Error

Forbidden

- `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

### V2ModelField

- `created_at` (datetime, optional)
- `created_by` (OutputActor, optional)
- `description` (string, optional)
- `example` (any, optional)
- `id` (string, optional)
- `label` (string, optional)
- `name` (string, optional)
- `remote_type` (string, optional)
- `type` (string, optional)
- `unique` (boolean, optional)
- `updated_at` (datetime, optional)
- `user_added` (boolean, optional)

### OutputActor

- `id` (string, optional)
- `name` (string, optional)
- `type` (string, optional)

## Examples

**Request**

```json
{
  "query": {
    "query": "select * from public.users"
  }
}
```

**Response**

```json
{
  "data": [
    {
      "created_at": "2024-01-15T09:30:00Z",
      "created_by": {
        "id": "12345678-1234-1234-1234-123456789012",
        "name": "John Doe",
        "type": "user"
      },
      "description": "Unique identifier",
      "example": null,
      "id": "248df4b7-aa70-47b8-a036-33ac447e668d",
      "label": "ID",
      "name": "id",
      "remote_type": "string",
      "type": "string",
      "unique": true,
      "updated_at": "2024-01-15T09:30:00Z",
      "user_added": false
    }
  ]
}
```

**SDK Code**

```python
import requests

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

payload = { "query": { "query": "select * from public.users" } }
headers = {
    "X-Polytomic-Version": "X-Polytomic-Version"
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers, auth=("<username>", "<password>"))

print(response.json())
```

```javascript
const url = 'https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/source/fields';
const credentials = btoa("<username>:<password>");

const options = {
  method: 'POST',
  headers: {
    'X-Polytomic-Version': 'X-Polytomic-Version',
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/json'
  },
  body: '{"query":{"query":"select * from public.users"}}'
};

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/source/fields"

	payload := strings.NewReader("{\n  \"query\": {\n    \"query\": \"select * from public.users\"\n  }\n}")

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

	req.Header.Add("X-Polytomic-Version", "X-Polytomic-Version")
	req.SetBasicAuth("<username>", "<password>")
	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/source/fields")

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

request = Net::HTTP::Post.new(url)
request["X-Polytomic-Version"] = 'X-Polytomic-Version'
request.basic_auth("<username>", "<password>")
request["Content-Type"] = 'application/json'
request.body = "{\n  \"query\": {\n    \"query\": \"select * from public.users\"\n  }\n}"

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/source/fields")
  .header("X-Polytomic-Version", "X-Polytomic-Version")
  .basicAuth("<username>", "<password>")
  .header("Content-Type", "application/json")
  .body("{\n  \"query\": {\n    \"query\": \"select * from public.users\"\n  }\n}")
  .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/source/fields', [
  'body' => '{
  "query": {
    "query": "select * from public.users"
  }
}',
  'headers' => [
    'Content-Type' => 'application/json',
    'X-Polytomic-Version' => 'X-Polytomic-Version',
  ],
    'auth' => ['<username>', '<password>'],
]);

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

```csharp
using RestSharp;
using RestSharp.Authenticators;

var client = new RestClient("https://app.polytomic.com/api/connections/248df4b7-aa70-47b8-a036-33ac447e668d/source/fields");
client.Authenticator = new HttpBasicAuthenticator("<username>", "<password>");
var request = new RestRequest(Method.POST);
request.AddHeader("X-Polytomic-Version", "X-Polytomic-Version");

request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"query\": {\n    \"query\": \"select * from public.users\"\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let credentials = Data("<username>:<password>".utf8).base64EncodedString()

let headers = [
  "X-Polytomic-Version": "X-Polytomic-Version",
  "Authorization": "Basic \(credentials)",
  "Content-Type": "application/json"
]
let parameters = ["query": ["query": "select * from public.users"]] 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/source/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()
```