Why transfer data manually when your website and newsletter system can be connected automatically? With professional newsletter API integration, we link your forms, shops, or CRM systems with your newsletter provider. Contacts, tags, and opt-ins are synchronized automatically.
Our Solution
Nakaryu connects your website and newsletter system via a newsletter API: setup, mapping, and synchronization between website, shop, CRM, and newsletter platform – technically clean and documented.
Technical Implementation
→ setup, mapping, testing & ongoing fixes as needed
Personal Support
→ direct inquiries, clear coordination, no ticket odyssey
Predictable & Transparent
→ clear add-on service instead of unpredictable integration projects
Cancelable Monthly
→ flexibly bookable when you need it
References & Case Studies
Trusted by
strong brands
Newsletter API Integration & Web Partners
For all industries: data flow that works reliably
No matter the industry: the stumbling blocks are similar. Forms don’t send data correctly, tags/lists are set incorrectly, double opt-in is inconsistent – or there is no clean synchronization between website and newsletter tool. Result: newsletter integration becomes a permanent construction site instead of a stable foundation for automations.
This is exactly where Nakaryu comes in: you get a team specialized in technical integration – with clear processes, short feedback loops and focus on a stable newsletter interface instead of shaky workarounds („ sometimes a plugin here, sometimes a Zap there”). We build clean field mapping, clear lists/tags, stable API calls, and a newsletter synchronization that remains reliable even with updates and form changes.
What’s special: we don’t think of integration just „somehow connected“ – but as a system. We define data points, check consent/double opt-in, test edge cases, and document the setup. Whether a simple website or a complex setup with CRM newsletter integration – we build the connection so that it is maintainable in the long term.
Plannable, fast, and transparent: as an add-on to the web design‑ flat rate with clear deliverables, fixed checklists, and a team that thinks technically. So your email marketing API becomes a reliable data channel – stable, traceable, and without tool chaos.
Online Shops & E-Commerce
Beauty & Wellness
Creatives, Media & Pop Culture
B2B, Coaching & Consulting
Real Estate & Architecture
Events & Conferences
Practices, Health & Fitness
Gastronomy, Hotel & Tourism
Education, Associations & Social
Crafts, Construction & Mobility
Lawyers & Tax Advisors
Industry & Research
Choose the right add-on for your newsletter API integration
No setup fee. Cancel monthly – risk-free.
With Nakaryu you get our complete range of services as a full-service flat rate – in every package. For this add-on, we focus on technology: newsletter API, WordPress newsletter integration, and mailing list integration. We build, test, and continuously stabilize the interface – so your data arrives cleanly and automations trigger correctly: everything is included.
The only difference between the packages is your monthly hourly quota – that is, how much Team Capacity you can use per month.
This is our pricing model:
Whether a small website or a large setup – the add-on works across industries and grows with your data structure.
More hours mean: more output, faster implementation, more integration tasks in parallel and shorter time-to-fix.
You decide how much capacity you need – we deliver integration, testing, and stabilization from a single source.
What makes Nakaryu special
Your benefits in all packages
Technical Check & Consultation
→ System selection, API check, data model & clear contacts
Forms & Data Transfer (Website)
→ WordPress form setup, field mapping, tags/list logic, and validation
Scalable for multiple tools
→ Setup for one or more newsletter systems (e.g. Brevo API, Mailchimp API, Klaviyo API, rapidmail API)
Clean newsletter synchronization
→ Automatically keep contacts, tags, lists, and status (opt-in) consistent
API Events & Automation Handling
→ Set up webhooks, events, API credits & triggers so that nothing „gets lost“
Template Modules & Integration
→ Integration on the website: signup, popups, preference center (if available)
Automation & Integrations
→ Interfaces, workflows (e.g. Make/Zapier/n8n) and clean handovers
Monitoring & Error Analysis
→ Logs, tests, quick corrections & support 7 days a week
Custom Mapping
→ Not a standard connector, but a data model tailored to your setup.
Clean Documentation
→ Documentation, checklists & handover to keep your setup maintainable
Testing & Quality Assurance
→ Test cases for opt-in, tags, events, duplicates & error handling
Interface Rollout
→ Go-live, staging/live check and secure transition without data loss
Data Protection & Consent Logic
→ Double opt-in, consent status and traceable processes.
Project & Task Management
→ Clear prioritization, central tasks & regular status updates
List Structure & Hygiene
→ Duplicate logic, tags/list concept and clean segment foundation
(Prerequisite) Website & Web Design Flat
→ The add-on is for existing web design‑flat customers here.
Add-on Package Selection
Choose your desired package
Starter
195 € per month
Entry: simple newsletter integration
2 hours / month
Ideal for getting started: One newsletter tool (e.g. Brevo, Mailchimp) is connected via API to a website form, including double opt-in and simple tag logic.
Traveler
695 € per month
More depth: Synchronization & automation triggers.
7 hours / month
Ideal if you need newsletter synchronization with tags/events, have multiple forms or sources, and require a stable API – including monitoring, error handling, and adjustments for changes.
Hero
1,895 € per month
Complex interface as a permanent setup.
20 hours / month
Ideal for setups with multiple lists, preference centers, webhooks, and deep CRM newsletter integration. We take care of further development, testing, and ongoing stabilization – to ensure the newsletter API scales reliably.
Legend
3,595 € per month
For multiple systems, many events & high complexity. Everything from „Hero“, plus:
40 hours / month
Ideal for large setups with multiple tools (e.g., Brevo API + Klaviyo API), complex event tracking, duplicate logic, and many data sources. Maximum capacity, high-priority support, and clean architecture – limited to a few slots.
Questions? We’re happy to help!
→ Write to hey@nakaryu.de, chat on WhatsApp, or call +49 152 58119266. We are happy to advise you.
We support all industries
When do I need which package?
Bring contacts cleanly into the system
GreenLeaf Landscaping
„GreenLeaf Landscaping is a regional garden and landscaping company with a simple WordPress website. New contact requests from the form should automatically land in Brevo instead of being transferred manually. With a clean newsletter API integration, the team saves time and can provide prospects directly with relevant information.“
Stabilize synchronization & triggers
Travel Agency Nordwind
„Contacts come to us through multiple forms and landing pages – depending on the travel destination and booking status. Nakaryu sets up the newsletter API so that tags are automatically set via events, contacts remain synchronized across all sources, and trigger emails (e.g., after a booking) are reliably sent. Including monitoring so errors are noticed before customers do.“
More sources, more logic, fewer errors
Electronics Store Voltario
„Our shop collects contacts via popups, checkout opt-in, and a customer account – previously maintained inconsistently. Nakaryu builds clean field mapping, synchronizes contacts, tags, and purchase status, sets webhooks for order events, and tests edge cases like duplicates or subsequent opt-in changes. This keeps the data base stable even as we continuously add new forms or campaigns.“
Enterprise integration across multiple systems
Nexora Industrial Solutions
„Nexora Industrial Solutions serves international B2B clients and uses multiple CRM, ERP, and marketing systems simultaneously. Newsletter data must remain synchronized across different locations and platforms. A scalable enterprise integration reliably connects all systems and creates a stable foundation for complex automations and global marketing processes.“
More visibility & brand presence
More performance & usability
More inquiries, leads & sales
More user satisfaction & WOW factor
15% discount on all packages
→ For clubs, creators & artists. Just send us a message.
Referring pays off
→ 100 € credit for every referred new customer.
This is how the onboarding works
Step by step to the API add-on
What makes us special
As unique as your
company
24/7 Fast Implementation & Personal Support
→ Quick help, adjustments & fixes – whenever something changes in the setup.
Cancelable monthly
→ Maximum flexibility without long-term contracts.
Always up to date
→ Modern tools, clean interfaces & stable newsletter API integrations.
All from one source – Website & API setup
→ Forms, events, synchronization & monitoring – one team, one setup.
Seamlessly integrated like your in-house team
→ Personal support, dedicated contacts, maximum transparency.
Team relief & planning reliability
→ Integration without new dev position – plannable via an hourly quota.
Internal tools & custom plugins
→ Efficient workflows with optimized processes & tailored solutions.
Plannable, transparent costs
→ fixed price without surprises – no hidden agency fees.
Future-proof and innovative
→ We continuously develop your newsletter integration with new requirements.
German quality, internationally scalable
→ Secure infrastructure & processes for reliable interfaces, made in Nuremberg.
Full Service vs Others
Why Nakaryu is better than
Agencies
You want a newsletter API integration that doesn’t break with every update? Then Nakaryu fits. We deliver newsletter integration not as a makeshift solution – but as a clean technical setup: mapping, consent logic, synchronization, testing and monitoring from one team.
Instead of just „connected“ we build a robust newsletter interface: clear data models, stable API calls and comprehensible documentation. This keeps lists, tags and events consistent – and your automations trigger reliably
And because the add-on is embedded in the web design‑flat processes, you save tool chaos, coordination and troubleshooting – in a plannable, transparent and maintainable way.
| Tasks / Benefits (Newsletter API Integration) | Nakaryu | Freelancer | Advertising Agency | In-house |
|---|---|---|---|---|
| API setup & technical integration (Brevo, Mailchimp, Klaviyo, Rapidmail, WordPress, CRM) | ✔ | ✔ | ✔ | ✔ |
| All from one source (Web flat rate, API connection, security, maintenance) | ✔ | ✖ | ✖ | ✔ |
| Ongoing maintenance & monitoring (webhooks, security, deliverability, GDPR) | ✔ | ✖ | ✖ | ✔ |
| Plannable costs (add-on instead of new project) | ✔ | ✖ | ✖ | ✖ |
| Flexibly expandable (additional triggers, lists, channels without new project) | ✔ | ✖ | ✖ | ✖ |
| Cancelable monthly | ✔ | ✔ | ✖ | ✖ |
| Costs | Add-on from 195€ / month | 4,000€+ / month | 2,000–20,000€+ | 10,000€+ / month |
Reviews
Real projects & the faces behind them
Timo Gerken
Head of International / FANDOM
★★★★★
“Thanks again for all your hard work on this. It was awesome working with you. We’ll certainly be reaching out for future campaigns.”
Lisa-Marie Sinnig
Account Manager / Mutabor GmbH
★★★★★
“A huge thank you for the great collaboration! We will definitely recommend you and if it fits for the next project, we will gladly come back to you!”
Patricia Brumme
Head of Marketing & PR / Enginsight GmbH
★★★★★
“So far everything is going well for us and everyone is very satisfied with the process.”
Rolf Naberink
Product Marketing Manager / Supermicro
★★★★★
“Definitely reaching out for future campaigns in Germany”
Frank Ferchau
Managing Director / Ferchau GmbH
★★★★★
“Simply excellent!”
Heinrich-Wilhelm Wudtke
Strategic Director / PURE Online GmbH
★★★★★
“The Belgian colleagues saw your work at the premiere in Berlin and are so impressed!”
Leandra Goldenstein
Marketing Coordinator / CrowdStrike
★★★★★
“Your commitment in lead acquisition was phenomenal, the communication always friendly and timely, and the on-site collaboration left nothing to be desired!”
Peggy Berger
Project Manager VW / Avantgarde GmbH
★★★★★
“Many thanks from our side! It was great and above all a real success 😊”
Cathalijne van Weert
Project Manager Events / Elfia
★★★★★
“Thank you both for being there!”
Claudia Löblein
Golfshop Nürnberg OHG
★★★★★
“Many thanks for your support, the shop is running smoothly!”
Questions about Newsletter API integration? We have answers
FAQ
How does Nakaryu work?
Nakaryu complements your Webdesign‑Flat with a technical add-on: Newsletter API integration, newsletter interface, and newsletter synchronization. You choose a package of hours, we deliver setup, testing, and stabilization – plannable, scalable, and well documented.
Who is Nakaryu suitable for?
For Webdesign‑Flat customers who want to connect their newsletter system via API: WordPress newsletter integration, mailing list integration, and CRM newsletter integration – without your own developer resources for interface topics.
How flexible is the collaboration?
You book monthly plannable hourly packages. Unused hours can be carried over for one month. The subscription can be canceled monthly at any time.
How does communication work?
You have fixed contacts and can reach us by email, chat, phone, or video call. We work like your internal team – fast, structured, and reliable.
How quickly can I start?
Usually within a few days after orderconfirmation and a short kickoff – so that we can immediately start the technical implementation.
What costs will I incur?
You only pay the booked monthly price. No hidden fees. External costs (e.g. tool licenses or API credits/volume) are transparently agreed with you in advance.
Additional costs
Licenses or tools run through your accounts by arrangement and are passed on 1:1. If your provider charges API credits, we take this into account in the setup and plan sparingly.
How are additional or overtime hours billed?
After exhausting the quota, you book additional hours – at a fixed rate of 95 € /h.
Is there a minimum term and notice period?
No, the add-on can be canceled monthly at any time.
What services are included?
As needed: Newsletter API setup, newsletter integration, field mapping, webhooks, newsletter synchronization, testing, monitoring, and documentation – plus stable processes to ensure the interface works long-term.
How quickly are tasks implemented?
Usually within a few days. Depending on priority, we coordinate schedules with you; urgent bugs in the interface can be fixed at short notice by arrangement.
How is support handled during collaboration?
Regular coordination, clear checklists, and transparent documentation ensure the newsletter API integration runs stably and you always have an overview of changes and tests.
Which newsletter systems do you support?
Depending on the setup, we support Brevo API, Mailchimp API, Klaviyo API, and rapidmail API among others.
Is WordPress newsletter integration possible?
Yes. We connect WordPress forms, WooCommerce, or custom functions with your newsletter system.
Are websites or shops included?
Web design is not part of the newsletter‑API‑integration itself but is a prerequisite because the add-on is intended for existing Webdesign‑Flat customers. Campaign management is offered separately if you want ongoing content support.
Can I add or change services at any time?
Yes. Within your hourly quota, integration tasks are prioritized freely. If more is needed, you book additional hours or switch to a larger package.
What is a newsletter API?
A newsletter API (Application Programming Interface) connects your website, online shop, or CRM directly with your newsletter system. This automatically transfers contacts, sign-ups, tags, and other data without manual import or export of lists. A professional newsletter API integration saves time, reduces errors, and ensures reliable automations.
Which newsletter systems do you support?
We support the connection of numerous newsletter systems and email marketing platforms. These include Brevo (formerly Sendinblue), Mailchimp, Klaviyo, rapidmail, and many other providers with an available API or interface. Custom systems or CRM solutions can also be integrated depending on technical infrastructure.
How does an API integration work?
At the start, we analyze your existing website, shop, or CRM as well as your newsletter system. Then we set up the appropriate newsletter API, define data mapping, and configure synchronizations, tags, triggers, and automations. After extensive testing, we ensure that new contacts, changes, and opt-ins are reliably transferred between all connected systems.
Can I connect multiple systems simultaneously?
Yes. Depending on requirements, multiple systems can be connected via a central newsletter API integration. For example, WordPress, WooCommerce, CRM systems, landing pages, or external forms can be synchronized with your newsletter provider. This keeps contacts, lists, and automations up to date and consistent across all data sources.
How are hours documented?
All hours are recorded in an online tool. You receive monthly summaries on request so you can see exactly how your quota was used.
This fits the full-service flat
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