This document provides guidance on using the API to add a payment transaction to an existing invoice through the set_invoice_transaction endpoint. Payment methods are identified by the NUMERIC codes the system uses internally — the full map is documented below and must be used as-is. After each transaction the platform recalculates the invoice totals and status (a fully covered invoice becomes paid).
To add a payment, provide your API credentials, the invoice (invoice_id or reference), the amount in the invoice currency and the numeric payment_type. The response returns the created transaction and the refreshed invoice totals and status.
https://easycms.fi/public_api/set_invoice_transaction/TOKEN (api_key): Your unique API key for authentication. How to Create API Credentials.username: Your login username.password: Your login password.account: Your specific account ID.invoice_id (integer): The numeric invoice id (either this or reference is required).reference (string): The invoice payment reference number (either this or invoice_id is required).amount (required, number > 0): The payment amount in the invoice's own currency. Partial payments are supported — send each payment as its own transaction call.payment_type (required, integer): The numeric payment-method code from the map below (the same numeric codes the system uses everywhere, e.g. in the cash-register integration and the admin transaction list):| payment_type | payment_method |
|---|---|
| 0 | bank_transfer |
| 1 | cash |
| 2 | card |
| 3 | online_banking |
| 4 | e_invoice |
| 5 | paypal |
| 6 | google_wallet |
| 7 | stripe |
| 20 | cash_on_pickup |
| 21 | cash_on_delivery |
| 25 | factoring |
| 30 | other_payments |
| 100 | customer_balance_credit_transfer |
| 110 | refund_from_invoice_total |
date (optional): The payment date, Y-m-d or dd.mm.YYYY (default: now).Notes:
entry_type 1) attributed to your API user, so the admin transaction list shows where each payment came from.total_paid, total_due and the invoice status automatically: the invoice flips to paid when the total is covered, is_partially_paid while it is not, and is_over_paid when it is exceeded.The transaction object echoes what was recorded (with the resolved payment_method name), and the invoice object carries the refreshed total_paid, total_due and the new status (paid when fully covered, otherwise open with is_partially_paid).
curl -X POST 'https://easycms.fi/public_api/set_invoice_transaction' \
-H 'Authorization1: TOKEN' \
-d 'username=USERNAME&password=PASSWORD&account=ACCOUNT_ID&invoice_id=1042&amount=380.63&payment_type=2'
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "https://easycms.fi/public_api/set_invoice_transaction",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => http_build_query(['username' => 'USERNAME', 'password' => 'PASSWORD', 'account' => 'ACCOUNT_ID', 'invoice_id' => '1042', 'amount' => '380.63', 'payment_type' => '2']),
CURLOPT_HTTPHEADER => array("Authorization1: TOKEN"),
));
$response = curl_exec($curl);
curl_close($curl);
echo $response;
import requests
url = "https://easycms.fi/public_api/set_invoice_transaction"
headers = {"Authorization1": "TOKEN"}
payload = {'username': 'USERNAME', 'password': 'PASSWORD', 'account': 'ACCOUNT_ID', 'invoice_id': '1042', 'amount': '380.63', 'payment_type': '2'}
response = requests.post(url, headers=headers, data=payload)
print(response.text)
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("https://easycms.fi/public_api/set_invoice_transaction"))
.headers("Authorization1", "TOKEN")
.POST(HttpRequest.BodyPublishers.ofString("username=USERNAME&password=PASSWORD&account=ACCOUNT_ID&invoice_id=1042&amount=380.63&payment_type=2"))
.build();
HttpResponse response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());
const https = require('https');
const data = new URLSearchParams({
"username": "USERNAME",
"password": "PASSWORD",
"account": "ACCOUNT_ID",
"invoice_id": "1042",
"amount": "380.63",
"payment_type": "2",
}).toString();
const options = {
hostname: 'easycms.fi',
path: '/public_api/set_invoice_transaction',
method: 'POST',
headers: {
'Authorization1': 'TOKEN',
'Content-Type': 'application/x-www-form-urlencoded',
'Content-Length': data.length
}
};
const req = https.request(options, (res) => {
let data = '';
res.on('data', (chunk) => { data += chunk; });
res.on('end', () => { console.log(data); });
});
req.on('error', (e) => { console.error(e); });
req.write(data);
req.end();
import React, { useEffect, useState } from 'react';
function App() {
const [responseText, setResponseText] = useState('');
useEffect(() => {
const fetchData = async () => {
try {
const response = await fetch('https://easycms.fi/public_api/set_invoice_transaction', {
method: 'POST',
headers: {'Authorization1': 'TOKEN', 'Content-Type': 'application/x-www-form-urlencoded'},
body: new URLSearchParams({"username": "USERNAME", "password": "PASSWORD", "account": "ACCOUNT_ID", "invoice_id": "1042", "amount": "380.63", "payment_type": "2"}).toString()
});
const data = await response.text();
setResponseText(data);
} catch (error) {
console.error(error);
}
};
fetchData();
}, []);
return ({responseText});
}
export default App;
// Kotlin example requires using a third-party library like OkHttp for POST requests with a body
// Kotlin Example using OkHttp for POST request
import okhttp3.OkHttpClient
import okhttp3.FormBody
import okhttp3.Request
fun main() {
val client = OkHttpClient()
val formBody = FormBody.Builder()
.add("username", "USERNAME")
.add("password", "PASSWORD")
.add("account", "ACCOUNT_ID")
.add("invoice_id", "1042")
.add("amount", "380.63")
.add("payment_type", "2")
.build()
val request = Request.Builder()
.url("https://easycms.fi/public_api/set_invoice_transaction")
.post(formBody)
.addHeader("Authorization1", "TOKEN")
.build()
client.newCall(request).execute().use { response ->
if (!response.isSuccessful) throw IOException("Unexpected code $response")
println(response.body?.string())
}
}
using System;
using System.Net.Http;
using System.Threading.Tasks;
class Program
{
static async Task Main()
{
var token = "TOKEN";
var content = new FormUrlEncodedContent(new[]
{
new KeyValuePair("username", "USERNAME"),
new KeyValuePair("password", "PASSWORD"),
new KeyValuePair("account", "ACCOUNT_ID"),
new KeyValuePair("invoice_id", "1042"),
new KeyValuePair("amount", "380.63"),
new KeyValuePair("payment_type", "2")
});
using (var httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Add("Authorization1", token);
var response = await httpClient.PostAsync("https://easycms.fi/public_api/set_invoice_transaction", content);
if (response.IsSuccessStatusCode)
{
var responseData = await response.Content.ReadAsStringAsync();
Console.WriteLine(responseData);
}
else
{
Console.WriteLine($"Error: {response.StatusCode}");
}
}
}
}
When you make a request to the endpoint, you receive a JSON response containing various keys and values. Here's an explanation of the response keys and their meanings:
{
"OUTPUT": {
"response_type": "success",
"message": "transaction_was_added_successfully",
"transaction": {
"transaction_id": "c1d0f2e9-5b7a-4c31-9f22-6a0b1c2d3e4f",
"invoice_id": 1042,
"payment_type": 2,
"payment_method": "card",
"amount": 380.63,
"date": "2026-10-07 09:11:04",
"entry_type": 1
},
"invoice": {
"invoice_id": 1042,
"reference": "10753096392167",
"total": 380.63,
"total_paid": 380.63,
"total_due": 0,
"status": "paid",
"status_flags": []
}
},
"INFO": { "start": 0, "limit": 50, "count": 1, "total_count": 1, "tip": "", "docs": "https://easycms.fi/DOCUMENTATION/bt5/set_invoice_transaction" }
}
Here are the possible error messages and their meanings:
invoice_id_or_reference_must_be_provided_via_api: Neither invoice_id nor reference was sent.invoice_not_found: No live invoice matches the id/reference in this account.invoice_is_cancelled_transactions_cannot_be_added: The invoice is cancelled.payment_type_must_be_one_of_the_documented_numeric_values_...: The payment_type is not in the numeric map (the message lists the valid codes).amount_must_be_a_positive_number: The amount is missing, not numeric or not positive.UN-AUTHORIZED - ...: Authentication failed (wrong TOKEN/username/password/account).