SDKs Overview

Languages

Each SDK is published to the native package registry for its ecosystem. Pick your language:

• Node.js / Bun: sevk on npm (docs)
• Python: sevk on PyPI (docs)
• PHP: sevk/sevk-php on Packagist (docs)
• Ruby: sevk on RubyGems (docs)
• Go: github.com/sevk-io/sevk-go (docs)
• Rust: sevk on crates.io (docs)
• Java: io.sevk:sevk-java on Maven Central (docs)
• .NET: Sevk on NuGet (docs)

Install

npm install sevk

pip install sevk

composer require sevk/sevk-php

gem install sevk

go get github.com/sevk-io/sevk-go

cargo add sevk

<dependency>
  <groupId>io.sevk</groupId>
  <artifactId>sevk-java</artifactId>
  <version>1.1.0</version>
</dependency>

dotnet add package Sevk

Initialize

Every SDK requires your API key. Grab one from the sevk dashboard under API Keys. The key is always passed explicitly; no SDK reads it from the environment.

import { Sevk } from 'sevk'

const sevk = new Sevk('sevk_full_xxxxxxxx')

from sevk import Sevk

sevk = Sevk("sevk_full_xxxxxxxx")

sevk := sevk.New("sevk_full_xxxxxxxx")

Resources

Every SDK covers the same resources. Method names and casing follow each language's conventions.

• sevk.emails: send, get, update, cancel, sendBulk
• sevk.contacts: create, get, update, delete, list, bulkImport (bulk_import in Python/Ruby, BulkImport in Go/.NET), bulkUpdate, activity
• sevk.audiences: create, get, update, delete, list, addContacts, listContacts, removeContact
• sevk.broadcasts: list, get, create, update, delete, send, cancel, test, analytics, status, emails, estimateRecipients, estimateCost, active
• sevk.domains: list, get, create, update, delete, verify, verifyInbound, dnsRecords, regions
• sevk.templates: list, get, create, update, delete, duplicate
• sevk.topics: scoped to an audience
• sevk.segments: scoped to an audience, preview before saving
• sevk.subscriptions: subscribe, unsubscribe
• sevk.webhooks: list, get, create, update, delete, test, events
• sevk.inbound: list, get, downloadAttachment, routes, blocklist, quota, security
• sevk.outbound: getQuota, updateQuota, pause, reset
• sevk.activity: list, stats
• sevk.usage: get

Your First Send

import { Sevk } from 'sevk'

const sevk = new Sevk(process.env.SEVK_API_KEY!)

const { id } = await sevk.emails.send({
  from: '[email protected]',
  to: '[email protected]',
  subject: 'First send',
  text: 'It worked.'
})

console.log(id)

import os

from sevk import Sevk

sevk = Sevk(os.environ["SEVK_API_KEY"])

email = sevk.emails.send({
    "from": "[email protected]",
    "to": "[email protected]",
    "subject": "First send",
    "text": "It worked.",
})

print(email["id"])

Scheduled Email

All eight SDKs support scheduled transactional email through the single-send method, followed by reschedule or cancel operations on the returned email id. The timestamp must include a timezone, be in the future, and be no more than 30 days ahead. Attachments and bulk scheduling are not supported. Quota and balance are reserved at acceptance and released on cancellation.

See the Node.js and Python lifecycle examples, plus the reschedule and cancel references. Changes are rejected after provider delivery starts. For safe send retries, persist the schedule with the payload and reuse the original idempotency key.

Errors

API failures, local request validation, and connection failures use each language's SDK error type. Catch that base type to handle request failures in one place. Use the machine code to distinguish validation, timeout, and connection errors.

Local validation uses VALIDATION_ERROR; timeouts use TIMEOUT, and connection failures use NETWORK_ERROR. Local validation sends no HTTP request. The status is 0 when unavailable, or None in Rust. API responses retain their actual HTTP status and any field details or retry delay supplied by the server.

import { SevkError, RateLimitError } from 'sevk'

try {
  await sevk.emails.send({ /* ... */ })
} catch (err) {
  if (!(err instanceof SevkError)) {
    throw err
  }

  console.error(err.code, err.statusCode, err.message, err.fields)
  if (err instanceof RateLimitError) {
    console.error(err.retryAfter)
  }
}

Types

Node/TypeScript ships typings in the package. Go, Rust, Java and .NET are statically typed.