SDKs

Use the official Resend SDKs against your MepMail instance — there is no client of ours to install.

MepMail speaks the Resend wire protocol, so there is no SDK of ours to install. The official Resend SDKs work as-is once you point them at your instance's API origin — which also means that moving off Resend costs you one line, not a rewrite of every call site.

Every snippet below was checked against the SDK's own source, and Node and Python were run against a live instance (send, delivered).

What the official SDKs can reach

Reaches MepMail	Not implemented
`emails` `domains` `contacts` `audiences` `broadcasts` `contactProperties` `segments` `suppressions` `templates` `topics` `webhooks`	`automations` `events` `logs` `oauthGrants`

The right-hand column answers 404. If a call you depend on is there, tell us — the wire format is compatible, so the endpoint is usually a day's work rather than a redesign.

Base URL

https://api-mepmail.je4ndev.com — what every example on this page uses.

Accounts are provisioned by invitation: there is no public signup. Write to us and we set up your account, domain, and first API key.

Trailing slash

The base URL is joined with the request path by each SDK, and they disagree about whether the path already starts with a slash. Getting it wrong is a 404 on every call, so it is worth copying exactly:

Base URL	SDKs
No trailing slash	Node, Python, Rust, Elixir
Trailing slash required	Go, Ruby
Either works	PHP, .NET

Node.js / TypeScript

resend on npm — Node 18+.

npm install resend

import { Resend } from "resend";

const resend = new Resend("ms_123", {
  baseUrl: "https://api-mepmail.je4ndev.com",
});

const { data, error } = await resend.emails.send({
  from: "Acme <[email protected]>",
  to: "[email protected]",
  subject: "Hello from MepMail",
  html: "<strong>It works!</strong>",
});

Python

resend on PyPI — Python 3.9+.

pip install resend

import resend

resend.api_key = "ms_123"
resend.api_url = "https://api-mepmail.je4ndev.com"  # no trailing slash

email = resend.Emails.send({
    "from": "Acme <[email protected]>",
    "to": "[email protected]",
    "subject": "Hello from MepMail",
    "html": "<strong>It works!</strong>",
})

PHP

resend/resend-php on Packagist — PHP 8.1+.

The base URL is not a constructor argument in PHP: the SDK reads it from the RESEND_BASE_URL environment variable when the client is created.

composer require resend/resend-php

putenv("RESEND_BASE_URL=https://api-mepmail.je4ndev.com");

$resend = Resend::client('ms_123');

$email = $resend->emails->send([
    'from' => 'Acme <[email protected]>',
    'to' => '[email protected]',
    'subject' => 'Hello from MepMail',
    'html' => '<strong>It works!</strong>',
]);

Ruby

resend on RubyGems — Ruby 3.0+.

Ruby also reads only the environment variable — and it reads it once, when the library is loaded, so it has to be set before require "resend". Note the trailing slash.

gem install resend

ENV["RESEND_BASE_URL"] = "https://api-mepmail.je4ndev.com/"

require "resend"
Resend.api_key = "ms_123"

email = Resend::Emails.send({
  "from" => "Acme <[email protected]>",
  "to" => "[email protected]",
  "subject" => "Hello from MepMail",
  "html" => "<strong>It works!</strong>"
})

Go

github.com/resend/resend-go/v4 — Go 1.21+.

Use the /v4 module path. The older github.com/resend/resend-go without the suffix is a 2023 tag that no longer compiles.

go get github.com/resend/resend-go/v4

import (
    "net/url"

    "github.com/resend/resend-go/v4"
)

client := resend.NewClient("ms_123")
client.BaseURL, _ = url.Parse("https://api-mepmail.je4ndev.com/")

sent, err := client.Emails.Send(&resend.SendEmailRequest{
    From:    "Acme <[email protected]>",
    To:      []string{"[email protected]"},
    Subject: "Hello from MepMail",
    Html:    "<strong>It works!</strong>",
})

Rust

resend-rs on crates.io — async (tokio + reqwest).

[dependencies]
resend-rs = "0.32"
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }

use resend_rs::types::CreateEmailBaseOptions;
use resend_rs::{Config, Resend};

let resend = Resend::with_config(
    Config::builder("ms_123")
        .base_url("https://api-mepmail.je4ndev.com".parse()?)
        .build(),
);

let sent = resend
    .emails
    .send(
        CreateEmailBaseOptions::new(
            "Acme <[email protected]>",
            ["[email protected]"],
            "Hello from MepMail",
        )
        .with_html("<strong>It works!</strong>"),
    )
    .await?;

Java

The official Java SDK pins https://api.resend.com in a constant and exposes no way to change it, so there is no Java snippet to point at us — talk HTTP directly instead:

var body = """
    {
      "from": "Acme <[email protected]>",
      "to": ["[email protected]"],
      "subject": "Hello from MepMail",
      "html": "<strong>It works!</strong>"
    }
    """;

var request = HttpRequest.newBuilder()
    .uri(URI.create("https://api-mepmail.je4ndev.com/emails"))
    .header("Authorization", "Bearer ms_123")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString(body))
    .build();

var response = HttpClient.newHttpClient()
    .send(request, HttpResponse.BodyHandlers.ofString());

.NET

Resend on NuGet — targets net8.0.

dotnet add package Resend

using Resend;

var options = new ResendClientOptions
{
    ApiToken = "ms_123",
    ApiUrl = "https://api-mepmail.je4ndev.com",
};

var resend = ResendClient.Create(options);

await resend.EmailSendAsync(new EmailMessage
{
    From = "Acme <[email protected]>",
    To = { "[email protected]" },
    Subject = "Hello from MepMail",
    HtmlBody = "<strong>It works!</strong>",
});

Elixir

resend on Hex — Elixir 1.15+. This one is community-maintained, not published by Resend, so treat its release cadence accordingly.

# mix.exs
def deps do
  [{:resend, "~> 1.0-rc"}]
end

client = Resend.client(
  api_key: "ms_123",
  base_url: "https://api-mepmail.je4ndev.com"
)

{:ok, email} =
  Resend.Emails.send(client, %{
    from: "Acme <[email protected]>",
    to: "[email protected]",
    subject: "Hello from MepMail",
    html: "<strong>It works!</strong>"
  })

The SMTP relay

Prefer SMTP? MepMail also runs a submission relay (STARTTLS, port 2587) for legacy clients and libraries that cannot change their base URL — Java above being one of them. Credentials are an API key, and the sending domain rules are the same as the API's. See Self-hosting → SMTP relay.

On this page