Attachments

#!/usr/bin/env bash
set -u
: "${MAILCHANNELS_API_KEY:?Set MAILCHANNELS_API_KEY before running}"
: "${FROM_EMAIL:?Set FROM_EMAIL (must be on a Domain-Lockdown-authorized domain)}"
: "${TO_EMAIL:?Set TO_EMAIL}"
: "${ATTACHMENT_PATH:?Set ATTACHMENT_PATH to the file you want to attach, e.g. ./logo.png}"

# Base64-encode the file. The -w0 flag (GNU base64) emits a single line with no
# wrapping; on macOS, drop -w0 — `base64` there doesn't wrap by default.
ATTACHMENT_BASE64=$(base64 -w0 "$ATTACHMENT_PATH")
ATTACHMENT_FILENAME=$(basename "$ATTACHMENT_PATH")

curl -X POST https://api.mailchannels.net/tx/v1/send \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: $MAILCHANNELS_API_KEY" \
  -d @- <<JSON
{
  "personalizations": [
    { "to": [{ "email": "$TO_EMAIL", "name": "Recipient" }] }
  ],
  "from": {
    "email": "$FROM_EMAIL",
    "name": "Your Name"
  },
  "subject": "Hello from MailChannels",
  "content": [
    {
      "type": "text/plain",
      "value": "Hello! See the attached file."
    }
  ],
  "attachments": [
    {
      "type": "image/png",
      "filename": "$ATTACHMENT_FILENAME",
      "content": "$ATTACHMENT_BASE64"
    }
  ]
}
JSON

import { readFile } from "node:fs/promises";
import { basename } from "node:path";
import { MailChannels } from "mailchannels-sdk";

const { MAILCHANNELS_API_KEY, FROM_EMAIL, TO_EMAIL, ATTACHMENT_PATH } = process.env;
if (!MAILCHANNELS_API_KEY) throw new Error("Set MAILCHANNELS_API_KEY before running");
if (!FROM_EMAIL) throw new Error("Set FROM_EMAIL (must be on a Domain-Lockdown-authorized domain)");
if (!TO_EMAIL) throw new Error("Set TO_EMAIL");
if (!ATTACHMENT_PATH) throw new Error("Set ATTACHMENT_PATH to the file you want to attach, e.g. ./logo.png");

const fileBytes = await readFile(ATTACHMENT_PATH);

const mailchannels = new MailChannels(MAILCHANNELS_API_KEY);

const { data, error } = await mailchannels.emails.send({
  from: { email: FROM_EMAIL, name: "Your Name" },
  to: { email: TO_EMAIL, name: "Recipient" },
  subject: "Hello from MailChannels",
  text: "Hello! See the attached file.",
  attachments: [
    {
      type: "image/png",
      filename: basename(ATTACHMENT_PATH),
      content: fileBytes.toString("base64"),
    },
  ],
});

if (error) {
  console.error("Send failed:", error);
  process.exit(1);
}
console.log(data);

import os
import sys
from pathlib import Path

import mailchannels

if not os.environ.get("MAILCHANNELS_API_KEY"):
    sys.exit("Set MAILCHANNELS_API_KEY before running")

from_email = os.environ.get("FROM_EMAIL")
to_email = os.environ.get("TO_EMAIL")
attachment_path = os.environ.get("ATTACHMENT_PATH")
if not from_email:
    sys.exit("Set FROM_EMAIL (must be on a Domain-Lockdown-authorized domain)")
if not to_email:
    sys.exit("Set TO_EMAIL")
if not attachment_path:
    sys.exit("Set ATTACHMENT_PATH to the file you want to attach, e.g. ./logo.png")

# Attachment.from_bytes base64-encodes the bytes and guesses the content type
# from the filename.
attachment = mailchannels.Attachment.from_bytes(
    Path(attachment_path).read_bytes(),
    filename=Path(attachment_path).name,
)

response = mailchannels.Emails.send(
    {
        "from": {"email": from_email, "name": "Your Name"},
        "to": [{"email": to_email, "name": "Recipient"}],
        "subject": "Hello from MailChannels",
        "text": "Hello! See the attached file.",
        "attachments": [attachment],
    }
)

print(response)

<?php

require_once __DIR__ . '/vendor/autoload.php';

use MailChannels\Client;

$api_key         = getenv('MAILCHANNELS_API_KEY') or exit("Error: MAILCHANNELS_API_KEY is not set\n");
$from_email      = getenv('FROM_EMAIL') or exit("Error: FROM_EMAIL is not set\n");
$to_email        = getenv('TO_EMAIL') or exit("Error: TO_EMAIL is not set\n");
$attachment_path = getenv('ATTACHMENT_PATH') or exit("Error: ATTACHMENT_PATH is not set\n");

$client = new Client(apiKey: $api_key);

$content = file_get_contents($attachment_path);
if ($content === false) {
    exit("Error: could not read file: {$attachment_path}\n");
}

$mime = mime_content_type($attachment_path) ?: 'application/octet-stream';

$response = $client->emails->send([
    'from'        => ['email' => $from_email, 'name' => 'Your Name'],
    'to'          => ['email' => $to_email, 'name' => 'Recipient'],
    'subject'     => 'Hello from MailChannels',
    'text'        => 'Hello! See the attached file.',
    'attachments' => [
        [
            'content'  => base64_encode($content),
            'filename' => basename($attachment_path),
            'type'     => $mime,
        ],
    ],
]);

print_r($response->toArray());