curl --request POST \
  --url https://app.sajn.se/api/v1/documents/{id}/links \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "toDocumentId": "cm4k2x9p10022abcd1234efgh",
  "linkType": "AMENDS"
}
'

import requests

url = "https://app.sajn.se/api/v1/documents/{id}/links"

payload = {
    "toDocumentId": "cm4k2x9p10022abcd1234efgh",
    "linkType": "AMENDS"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({toDocumentId: 'cm4k2x9p10022abcd1234efgh', linkType: 'AMENDS'})
};

fetch('https://app.sajn.se/api/v1/documents/{id}/links', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.sajn.se/api/v1/documents/{id}/links",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'toDocumentId' => 'cm4k2x9p10022abcd1234efgh',
    'linkType' => 'AMENDS'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://app.sajn.se/api/v1/documents/{id}/links"

	payload := strings.NewReader("{\n  \"toDocumentId\": \"cm4k2x9p10022abcd1234efgh\",\n  \"linkType\": \"AMENDS\"\n}")

	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(string(body))

}

HttpResponse<String> response = Unirest.post("https://app.sajn.se/api/v1/documents/{id}/links")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"toDocumentId\": \"cm4k2x9p10022abcd1234efgh\",\n  \"linkType\": \"AMENDS\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.sajn.se/api/v1/documents/{id}/links")

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 = "{\n  \"toDocumentId\": \"cm4k2x9p10022abcd1234efgh\",\n  \"linkType\": \"AMENDS\"\n}"

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

{
  "id": "cm4k2x9p10021abcd1234efgh",
  "fromDocumentId": "cm4k2x9p10003abcd1234efgh",
  "toDocumentId": "cm4k2x9p10022abcd1234efgh",
  "linkType": "AMENDS",
  "direction": "FROM",
  "origin": "manual",
  "createdAt": "2026-09-28T09:12:00.000Z",
  "target": {
    "id": "cm4k2x9p10022abcd1234efgh",
    "name": "Sekretessavtal – Kai Lindqvist",
    "status": "COMPLETED",
    "workspaceId": "cm4k2x9p10001abcd1234efgh"
  }
}

{
  "code": "VALIDATION_FAILED",
  "message": "Invalid input: expected string, received undefined",
  "userMessage": "Förfrågan innehåller ogiltiga värden.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2",
  "issues": [
    {
      "path": "toDocumentId",
      "code": "INVALID_TYPE",
      "message": "Invalid input: expected string, received undefined"
    }
  ]
}

{
  "code": "UNAUTHORIZED",
  "message": "Invalid API token",
  "userMessage": "Ogiltig API-nyckel",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2"
}

{
  "code": "INSUFFICIENT_SCOPE",
  "message": "Insufficient OAuth scope: requires documents:write",
  "userMessage": "Applikationen saknar behörighet (scope) för denna åtgärd.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2",
  "requiredScopes": [
    "documents:write"
  ],
  "grantedScopes": [
    "profile:read"
  ]
}

{
  "code": "NOT_FOUND",
  "message": "Document link not found",
  "userMessage": "Resursen hittades inte.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2",
  "resource": "link"
}

{
  "code": "INVALID_STATE",
  "message": "The resource's current state doesn't allow the operation, such as editing a document that was already sent or downloading a file that isn't produced yet.",
  "userMessage": "Åtgärden är inte möjlig i resursens nuvarande status.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2"
}

{
  "code": "RATE_LIMITED",
  "message": "API rate limit exceeded",
  "userMessage": "För många förfrågningar. Försök igen om en stund.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2"
}

{
  "code": "INTERNAL_ERROR",
  "message": "Internal server error",
  "userMessage": "Något gick fel.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2"
}

{
  "code": "UPSTREAM_UNAVAILABLE",
  "message": "A service the operation depends on, such as an eID provider or a connected integration, failed or is unavailable. Retry with exponential backoff.",
  "userMessage": "En extern tjänst svarar inte just nu. Försök igen om en stund.",
  "requestId": "req_V1StGXR8Z5jdHi6BmyT2"
}