Ark vs Onthen

Built for Multi-Tenant Platforms

Ark is uniquely designed for platforms with multiple customers, making tenant isolation the default. Each customer gets their own completely separate environment for domains, sending logs, analytics, and deliverability metrics. This means you never have to build complex separation logic on top of a generic email API. Everything is organized per customer from the start, saving you months of development time and making support and debugging straightforward.

Automated Domain & DNS Configuration

Onboarding a new customer domain is simple and fast. Ark automatically detects the customer's DNS provider (like Cloudflare, GoDaddy, or Route53) and provides them with the exact, simple steps to add the necessary records. For some providers, Ark can even configure the DNS automatically. This eliminates lengthy support calls explaining TXT and CNAME records, enabling a truly self-service experience that scales.

Per-Customer Visibility & Debugging

When a customer reports an email issue, you can find the answer instantly. Ark provides isolated logs and analytics for every single customer domain. You can search, filter, and debug delivery problems across your entire customer base from one unified dashboard. This deep, per-customer visibility turns a nightmare troubleshooting session into a simple, quick check, ensuring high customer satisfaction.

AI-Native Integration Tools

Ark is built for the modern developer workflow. It comes with AI-readable documentation and a native MCP server with 26 tools, allowing AI coding assistants like Claude, Cursor, or GitHub Copilot to understand the API perfectly. This enables your AI assistant to generate production-ready code for features like user verification or password resets on the first try, helping you ship in minutes instead of days.

Branded Onboarding Pages

Create a seamless and professional first impression with fully customized onboarding pages. Simply upload your logo and choose a primary color, and Onthen applies your branding across the entire participant experience. This includes the task page itself and all automated emails sent from the system. A branded page builds trust, reinforces your company identity, and makes the onboarding process feel like a natural extension of your service, not a generic third-party tool.

Flexible Task Actions & Automation

Move beyond simple checklists with powerful, actionable tasks. Onthen offers a variety of built-in actions like secure document uploads, form fills, identity verification (KYC), and photo requests. You can combine these into a reusable template and set up automatic nudges for overdue tasks. This means you build your perfect process once, and Onthen handles the repetitive follow-up work, keeping every onboarding on track without you having to chase people down manually.

Built-in Collaboration Tools

Foster clear communication and keep projects moving directly on the task page. Participants can ask questions and you can provide answers using the comment feature, ensuring all context stays with the relevant task. Participants can even delegate tasks to colleagues from the same page. This "one page for everyone" approach means you see exactly what your participants see, eliminating confusion and keeping all communication centralized and actionable.

CRM Synchronization

Onthen understands that your CRM is your central source of truth. It seamlessly bridges the gap by syncing every action taken during onboarding directly back to your CRM. Data collected from forms, uploaded documents, and task completion statuses are all logged to the relevant contact's timeline and can populate custom fields. This eliminates double data entry, ensures your records are always up-to-date, and gives your entire team full visibility.

Customer Relationship Management (CRM) Tools

CRM platforms need to send emails like lead notifications, meeting reminders, and outreach sequences on behalf of their users. With Ark, each sales team can send emails from their own company domain (e.g., [email protected]), maintaining brand consistency and improving deliverability, all managed seamlessly from the CRM's single interface.

Helpdesk & Customer Support Software

Helpdesk platforms send ticket updates, agent replies, and support notifications. Ark allows each business using the software to send these emails from their own support domain (like [email protected]). This white-label experience makes the helpdesk feel like an integrated part of the customer's business operations.

Invoicing & Billing Platforms

Invoicing tools send critical financial documents that must come from a trusted, customer-owned domain. Ark enables these platforms to send invoices, payment receipts, and reminders from addresses like [email protected], which looks professional, builds trust, and reduces the chance of invoices being marked as spam.

Scheduling & Booking Applications

Scheduling apps send confirmation emails, calendar invites, and reminders. Using Ark, a fitness studio or consultant can send these appointments from their own business domain (e.g., [email protected]). This reinforces their brand with every customer interaction and ensures high delivery rates for time-sensitive communications.

Client Onboarding for Service Businesses

Perfect for agencies, consultants, and financial advisors. Use Onthen to gather client information, contracts, brand assets, and project briefs through a structured checklist. Instead of sending multiple emails with attachments, you provide one clean link. Clients complete tasks at their own pace, and all collected data flows automatically into your CRM, making kick-off meetings more productive and setting a professional tone from the very start.

Employee & New Hire Onboarding

Streamline the first-day experience for new team members. HR teams can create a checklist that includes submitting payroll details, signing policy documents, completing training modules, and setting up IT access. New hires have a clear roadmap of what they need to do before day one, reducing anxiety and administrative burden on HR. Automated reminders ensure forms are completed on time.

Tenant and Resident Screening for Property Management

Simplify the rental application and move-in process. Property managers can use Onthen to create a flow that includes background checks, proof of income uploads, lease signing, and initial payment collection. The built-in identity verification (KYC) adds a layer of security and compliance. All documents and data are collected in one organized place and synced to the property management CRM.

Customer Verification for E-commerce & Platforms

Ideal for marketplaces, fintech apps, or age-restricted services that require user verification. Integrate KYC, proof of address, and age validation tasks directly into your sign-up flow. Customers can verify their identity quickly and securely from the same branded page where they signed up, reducing drop-off rates and manual review work for your team while maintaining regulatory compliance.

Ark is the email API designed specifically for developers who build multi-tenant software platforms. If you're creating a CRM, helpdesk, invoicing tool, scheduling app, or any product where your customers need to send emails from their own domains, Ark is built for you. Unlike generic email services that assume one company, one sender, Ark is purpose-built from the ground up to handle hundreds or thousands of unique customer domains effortlessly. Its core value is eliminating the immense infrastructure headache of managing SPF, DKIM, domain verification, and per-customer email logs. With Ark, you integrate once and then let your customers connect their own domains in minutes through a self-service process. This means you can offer true white-label email, where invoices come from [email protected] and notifications from [email protected], making your platform feel like a native part of their business. Ark provides AI-readable documentation and tools to speed up integration, but its real superpower is giving you a single dashboard to manage, monitor, and debug email for every single customer, so you can stop building email infrastructure and focus on your actual product.

Onthen is your all-in-one solution to transform messy, stressful onboarding into a smooth, professional, and automated experience. It's designed for businesses, teams, and professionals who need to onboard clients, customers, or new hires efficiently. Instead of juggling endless email chains, shared documents, and constant follow-up messages, Onthen centralizes everything onto a single, beautifully branded webpage. You simply send one link to your participant, and they get a clear checklist of tasks to complete. This eliminates confusion, reduces administrative work, and gets you the information you need faster. The core value of Onthen is frictionless collaboration: it creates one shared space where you and your participants can work together seamlessly, with everything automatically syncing to your CRM to keep your records perfect. It’s built to save you time, impress your clients with a modern process, and ensure no task ever falls through the cracks again.

Who is Ark for?

Ark is specifically built for developers and companies building B2B software platforms (SaaS) where their customers need to send email. This includes products like CRMs, helpdesks, invoicing tools, scheduling apps, marketing automation, and more. If your product sends email "on behalf of" your users, Ark is designed for you.

How does domain onboarding work for my customers?

The process is designed to be self-service. When your customer needs to add their domain, your app directs them to a simple interface (or uses Ark's API). Ark identifies their DNS provider and gives them clear, step-by-step instructions. For supported providers, it can even set up the DNS records automatically, often completing verification in just a couple of minutes without your support team's help.

How is Ark different from Resend or SendGrid?

Services like Resend, SendGrid, and Amazon SES are built for a single company to send its own emails. Ark is built for platforms with many customers. The key difference is multi-tenancy: Ark provides built-in, secure isolation for each customer's domains, logs, and analytics. Trying to achieve this with other tools requires building a complex management layer on top of their API.

What kind of support and reliability does Ark offer?

Ark is built for production use with sub-second email delivery speeds and a 99.9%+ deliverability rate. It includes comprehensive features for monitoring and debugging, giving you and your customers transparency into email performance. You can scale from a few domains to thousands without worrying about infrastructure.

How does Onthen reduce friction for participants?

Onthen is designed to be incredibly user-friendly. Participants don't need to create an account or remember a password. They simply click the unique link you send them and arrive at a single, clear page with their personalized checklist. The interface is intuitive, guiding them step-by-step through tasks like uploading documents or filling out forms. This removes all technical barriers, making it easy for anyone to complete their required actions quickly.

Can I reuse onboarding processes for different people?

Absolutely! A key strength of Onthen is the ability to create templates. You can build your ideal onboarding workflow once—with all the necessary tasks, instructions, and automations—and save it as a template. Then, for every new client, employee, or customer, you simply launch a new instance from that template. This ensures consistency, saves you immense time, and allows you to perfect your process over time.

What kind of integrations does Onthen support?

Onthen focuses on deeply integrating with your Customer Relationship Management (CRM) system to act as a powerful data bridge. It syncs all onboarding activity, collected data, and document links directly to contact records in your CRM. While the provided content emphasizes CRM sync, it also mentions a growing library of third-party app actions, suggesting flexibility to connect with other tools to trigger tasks or share data.

How does Onthen handle communication and reminders?

Onthen automates communication to keep things moving. You can set up automatic email nudges that are sent to participants if a task becomes overdue. Furthermore, the system can send branded weekly digest emails to both you and the participant, summarizing what's been completed and what's still outstanding. All task-specific communication happens via comments on the page itself, keeping everything organized and in context.

Ark is an AI-first email API designed for developers who build applications with AI assistants. It belongs to the category of transactional email services, which handle automated emails like user verification and password resets. Developers often look for alternatives to find the best fit for their specific project. Common reasons include budget constraints, the need for different features, or a requirement to integrate with a particular tech stack or platform that might not be fully supported. When evaluating alternatives, focus on key factors like ease of integration, especially with AI tools, delivery speed and reliability, transparent and scalable pricing, and the quality of developer documentation and support. The right choice should remove complexity, not add it.

Onthen is a customer support tool that simplifies client and employee onboarding. It replaces messy email chains with a single, automated checklist page to keep everyone on track. This type of software helps teams collect information and manage tasks seamlessly during a new customer or hire's first steps. People often explore alternatives to find a better fit for their budget or specific workflow. Some may need deeper integrations with other business software, while others might look for a different set of features or a more customizable platform. It's a common step in finding the perfect tool for your team's unique needs. When evaluating other options, focus on what matters most for your onboarding process. Key considerations include ease of use for your clients, automation capabilities, and how well the tool connects with your existing systems like your CRM. The goal is to maintain that seamless, professional experience Onthen provides, but tailored to your requirements.