Create a list

POST/api/v2/lists

Returns 201 with the new list.

Needs an API key with the newsletter scope. Scopes

Parameters

Body

namestringrequired

The list's name.

descriptionstring

A note for your team.

from_namestring

Default sender name.

from_addressstring

Default sender address.

reply_tostring

Stored with the list.

Notes

from_address is the default sender for broadcasts and sequences on the list; use an active address on a verified domain.

curl -X POST "https://api.koltrix.com/api/v2/lists" \
  -H "Authorization: Bearer $KOLTRIX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "name": "Product updates",
  "description": "What shipped this month",
  "from_name": "Acme",
  "from_address": "[email protected]"
}'

const res = await fetch("https://api.koltrix.com/api/v2/lists", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.KOLTRIX_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "name": "Product updates",
    "description": "What shipped this month",
    "from_name": "Acme",
    "from_address": "[email protected]"
  }),
});

console.log(res.status, await res.json());

import os, requests

res = requests.post(
    "https://api.koltrix.com/api/v2/lists",
    headers={
        "Authorization": f"Bearer {os.environ['KOLTRIX_API_KEY']}",
    },
    json={
        "name": "Product updates",
        "description": "What shipped this month",
        "from_name": "Acme",
        "from_address": "[email protected]"
    },
)
print(res.status_code, res.json())

package main

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

func main() {
	body := strings.NewReader(`{
  "name": "Product updates",
  "description": "What shipped this month",
  "from_name": "Acme",
  "from_address": "[email protected]"
}`)
	req, _ := http.NewRequest("POST", "https://api.koltrix.com/api/v2/lists", body)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+os.Getenv("KOLTRIX_API_KEY"))

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.StatusCode, string(out))
}

<?php

$ch = curl_init("https://api.koltrix.com/api/v2/lists");
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer " . getenv("KOLTRIX_API_KEY"),
        "Content-Type: application/json",
    ],
    CURLOPT_POSTFIELDS => json_encode([
        "name" => "Product updates",
        "description" => "What shipped this month",
        "from_name" => "Acme",
        "from_address" => "[email protected]",
    ]),
]);

$response = curl_exec($ch);
echo curl_getinfo($ch, CURLINFO_HTTP_CODE), " ", $response;

Created.

{
  "id": "0b3c6d2e-91f4-4a7b-8c5d-2e3f4a5b6c7d",
  "name": "Product updates",
  "description": "What shipped this month",
  "from_name": "Acme",
  "from_address": "[email protected]",
  "reply_to": "",
  "subscriber_count": 0,
  "created_at": "2026-10-02T10:11:12Z",
  "updated_at": "2026-10-02T10:11:12Z"
}

A required field is missing or invalid. The text names the problem.

{
  "error": "name is required"
}

The API key is missing, malformed, unknown or revoked.

{
  "error": "invalid or revoked api key"
}

The key is valid but does not have the newsletter scope.

{
  "error": "missing permission: newsletter"
}

More than 60 requests a minute on this key. Wait Retry-After seconds. No code field.

Retry-After: 60

{
  "error": "rate limit exceeded — 60 requests per minute per API key"
}

Try it below with your own key. Every sample reads the key from KOLTRIX_API_KEY.

Try it

Send this request from your browser.

Input

What you send

API key

Stays in this browser tab (sessionStorage) and goes only to api.koltrix.com. Create one under Settings → API keys.

Requests are real and this one changes data in your workspace. Koltrix has no test mode, so use a dedicated key with only the permissions you need and revoke it when you are done.

namestringrequired

descriptionstring

from_namestring

from_addressstring

reply_tostring

Request body · JSON

Valid JSON. The fields above and this editor stay in sync.

POSThttps://api.koltrix.com/api/v2/lists

Output

What comes back

The response appears here.
Press Send request.