List every dated API version and how to pin one (public, no auth).

Discovery endpoint for dated versioning. Returns every supported version with a human- and agent-readable changelog, the current version, and how to pin one via the Invoice-Version header. Requires no API key.

GET /v1/versions

List every dated API version and how to pin one (public, no auth).

cURL

curl --request GET \
  --url https://api.newinvoice.dev/v1/versions

import requests

url = "https://api.newinvoice.dev/v1/versions"

response = requests.get(url)

print(response.text)

const options = {method: 'GET'};

fetch('https://api.newinvoice.dev/v1/versions', 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://api.newinvoice.dev/v1/versions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
]);

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

curl_close($curl);

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

package main

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

func main() {

	url := "https://api.newinvoice.dev/v1/versions"

	req, _ := http.NewRequest("GET", url, nil)

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.newinvoice.dev/v1/versions")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.newinvoice.dev/v1/versions")

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

request = Net::HTTP::Get.new(url)

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

200

{
  "object": "list",
  "data": [
    {
      "version": "2026-07-10",
      "summary": "Initial dated release.",
      "changes": [
        "Initial public API surface."
      ]
    },
    {
      "version": "2026-07-15",
      "summary": "Adds machine-navigable error and list metadata.",
      "changes": [
        "problem+json error bodies now include `doc_url` (absolute link to the error reference).",
        "List envelopes now include `url` (the path the list was requested from)."
      ]
    }
  ],
  "current": "2026-07-15",
  "how_to_pin": "Pin a version by sending the `Invoice-Version: <date>` request header, or by attaching a pinned version to an API key. Omit both to track the current version. An unknown version in the header is rejected with 400 request.invalid_version."
}

Headers

Invoice-Version · string

Pin a dated API release (Stripe-style). Omit to use the current version. An unknown value returns 400 request.invalid_version. Echoed back on every response.

Example:

"2026-07-10"

Invoice-Account · string

Connect: act on behalf of one of your connected accounts (its acct_…/org_… id). Omit to act as your own organization. Not honored on /v1/api_keys.

Example:

"org_2P9connectedacct"

Response

200 - application/json

The version registry.

object · enum<string> · required

Available options: list

current · string · required

how_to_pin · string · required

data · object[] · required

Show child attributes