curl --request POST \
  --url https://matcher.sandbox.lerian.net/v1/imports/contexts/{contextId}/sources/{sourceId}/preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file=@example-file \
  --form max_rows=123

package main

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

func main() {

	url := "https://matcher.sandbox.lerian.net/v1/imports/contexts/{contextId}/sources/{sourceId}/preview"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"max_rows\"\r\n\r\n123\r\n-----011000010111000001101001--")

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

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "multipart/form-data")

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

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

	fmt.Println(string(body))

}

const form = new FormData();
form.append('file', '<string>');
form.append('max_rows', '123');

const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

options.body = form;

fetch('https://matcher.sandbox.lerian.net/v1/imports/contexts/{contextId}/sources/{sourceId}/preview', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://matcher.sandbox.lerian.net/v1/imports/contexts/{contextId}/sources/{sourceId}/preview"

files = { "file": ("example-file", open("example-file", "rb")) }
payload = { "max_rows": "123" }
headers = {"Authorization": "Bearer <token>"}

response = requests.post(url, data=payload, files=files, headers=headers)

print(response.text)