Onsai
Onsai is an agentic AI platform built solely for hotels and serviced apartments. Its voice, chat and email agents answer guest calls around the clock, book directly inside the PMS and verify OTA commission invoices.
What is Onsai?
Onsai is an agentic AI platform for the hospitality industry, published by Onsai GmbH of Leipzig, Germany. Where a classic chatbot answers questions, Onsai is positioned as software that acts: it takes decisions and completes processes on its own, and its central promise is that a hotel never misses a call again.
The platform is sold as a suite of five agents. The Voice Agent holds natural phone conversations around the clock, detects the caller's language automatically among more than 25 languages, and can switch language in the middle of a conversation. It understands hotel-specific vocabulary such as room categories and rate structures, offers a choice of 25 voices to match a brand, and transfers complex cases to a human with the full context. The Messaging Agent carries the same sector-specific training across website chat and WhatsApp, feeding a dashboard unified with voice. The Email Agent, announced as coming soon, automates replies to guest emails using live PMS data and plugs into Microsoft 365 and Gmail. Two further agents work on revenue rather than conversation: Commission Check reconciles OTA commission statements against real PMS data and detects incorrect charges, while Reservation Check validates OTA reservations and either corrects faulty entries or alerts the team.
The differentiator Onsai argues hardest is depth of integration. Rather than reading availability from a widget, the agents write directly into the property management system, with named integrations for Apaleo, Mews and Oracle Opera Cloud, plus HotelNetSolutions, HotelPartner and LikeMagic; the vendor claims more than 500 PMS reachable through middleware. A multi-property architecture allows one hotline for a whole group, with routing and guest recognition across sites.
The second argument is sovereignty: open-source models, hosting in Germany, optional on-premise deployment, and claimed independence from US cloud services. Named customers include Titanic Hotels, Halbersbacher Hospitality, Kongresshotel Potsdam and Göbel Hotels, and the company has collected several German hospitality awards since 2024.
What it does
- Answer every inbound guest call automatically, 24/7, in more than 25 languages
- Take a booking end-to-end during the call and write it straight into the property management system
- Handle website chat, WhatsApp and email enquiries with live PMS data behind the answer
- Switch language mid-conversation when a guest does, without dropping context
- Check OTA commission statements against actual PMS data and flag incorrect charges
- Validate OTA reservations, correct faulty entries or alert the team with an error report
- Transfer complex cases to the right staff member with the full conversation context attached
When to use Onsai / When not to
A quick filter to help you decide if Onsai is the right fit.
When to use Onsai
- Hotels that lose revenue because calls go unanswered at peak times or outside office hours
- Hotel groups running several properties that want one hotline, intelligent routing and guest recognition across sites
- Serviced apartment and aparthotel operators with small on-site teams and no permanent front desk
- Properties already running Apaleo, Mews or Oracle Opera Cloud that want booking taken end-to-end inside the PMS
- German and European operators for whom EU hosting, open-source models and data sovereignty are a purchasing condition
When not to use Onsai
- Businesses outside hospitality: Onsai is a declared sector specialist, not a general-purpose voice bot
- Teams that want to build their own integration, since Onsai publishes no public API and no developer documentation
- Buyers looking for instant self-service sign-up, as onboarding runs through a contract and a guided go-live
- Very small properties with a budget below EUR 199 per month, because there is no permanent free plan
- Anyone expecting a mobile application, as Onsai ships neither an iOS nor an Android app
How to use Onsai
A typical end-to-end flow, from setup to results.
- Book a personalised demo from the website, or contact the team directly
- Work through a sparring session in which Onsai maps your call volumes and operational pain points
- Get access to a free test system to try the agents before committing to anything
- Agree the service package and sign the software usage agreement, as there is no self-service sign-up
- Connect your property management system, whether Apaleo, Mews, Oracle Opera Cloud or another via middleware
- Connect the telephone system and, for the messaging agents, the chat, WhatsApp or mailbox channels
- Configure the agent's brand voice, tone, hotel policies and services during the two hours of guided onboarding
- Fill the editable knowledge base, per property and at group level, so the agent answers with your own facts
- Set the operational workflows such as VIP handling, whitelisted numbers and transfer rules
- Go live within the ten working days the vendor announces, then monitor calls in the analytics dashboard
Pros & Cons
Pros
- A declared hospitality specialist: the agents are trained on hotel vocabulary and workflows rather than adapted from a generic bot
- Booking is completed inside the PMS during the call, with no detour through a booking link
- Strong data sovereignty position: open-source models, hosting in Germany and an optional on-premise deployment
- The entry price is published and legible at EUR 199 per month, which is uncommon in this market
- Billing is per call and never per room, so adding rooms does not mechanically raise the bill
- More than 25 conversational languages with mid-conversation switching suits an international guest mix
- Named customers, a published case study with figures, and several German hospitality awards in 2024 and 2025
Cons
- No public API and no developer documentation, so integrations depend entirely on the vendor
- No pricing page anywhere on the site: the only published amounts sit on the competitor comparison pages
- No permanent free plan and no self-service purchase, since a signed contract is required
- The Email Agent is still announced as coming soon while being presented alongside the delivered agents
- No security certification is claimed at all, neither ISO 27001 nor SOC 2, despite the sovereignty pitch
- No subprocessor list is published and no retention period is quantified in the privacy policy
- Interface and documentation exist in English and German only, and there is no mobile application
Pricing & Plans
There is no permanent free plan. The lowest published entry point is the VOICE 100 plan at EUR 199 per month, which includes 100 calls regardless of their duration and the deep PMS integration, with no onboarding fee. Billing is per call rather than per room. A free demo and a free test system are offered beforehand, payment starting only at go-live. No price is published for the Messaging, Email, Commission Check or Reservation Check modules. Note that these amounts are not published on a pricing page, which does not exist on the site, but on the vendor's comparison pages.
- VOICE 100 — EUR 199 per month
- including 100 calls regardless of duration
- deep PMS integration and no onboarding fee
- Messaging Agent
- Email Agent
- Commission Check and Reservation Check — sold as modules
- no price published
- ITB 2026 trade show offer (time-limited
- signature required before 13 March 2026) — EUR 150 per month from go-live plus EUR 0.45 per call
- six-month minimum term
Data, GDPR & hosting
A consolidated view of how Onsai handles your data.
GDPR overview
Onsai states GDPR compliance explicitly and repeatedly: the privacy policy opens on processing carried out in accordance with the GDPR, and the site markets itself as "100% GDPR compliant" with "GDPR by design". Concrete mentions are present. The controller is named with a postal address and an email. The full list of data subject rights is reproduced. Transfers outside the European Economic Area are covered by a clause limiting them to countries offering an adequate level of protection or to appropriate safeguards such as Standard Contractual Clauses. A separate data processing agreement is contractually promised for customer data. Two things are absent: no Data Protection Officer is named, the section carrying that heading in fact designating the controller, and no subprocessor list is published. No Article 27 representative is designated, which is consistent with an EU-established company.
Who owns the data?
The data controller is Onsai GmbH, Petersstraße 22 / Sporergäßchen 2, 04109 Leipzig, Germany, reachable at mail@onsai.com. The privacy policy in force is dated 1 October 2024. Onsai processes contact details, usage data, billing data and communication data for the purposes it lists: delivering and improving the service, invoicing, and marketing. For customer data handled on behalf of a hotel, the terms of use provide that a separate data processing agreement is concluded, which places the hotel in the controller role and Onsai in the processor role. The vendor states that guest data is not passed to closed third-party systems in the United States to train their models.
Reuse rights
The published documents do not grant the customer any reuse licence over data held by Onsai, and they do not describe an export or data-portability feature inside the product. What the privacy policy does grant is the set of GDPR rights: a data subject may at any time and free of charge request information about the personal data stored, withdraw consent, and ask for access, deletion, rectification, restriction and portability, unless Onsai is legally required to retain the data. Separately, the terms of use reserve Onsai the right to use the customer's name and logo as a commercial reference, which is a reuse right running in the opposite direction and worth noting before signing.
Data retention & training
Hosting summary
Onsai states that guest data is hosted in Europe, and more precisely in Germany, and that it stays there. The vendor presents this as a design choice rather than an option: it runs open-source AI models hosted in Europe and claims independence from US cloud services, explicitly so that guest data is not sent to closed systems in the United States. For customers who need more, on-premise hosting is offered as an option for maximum data sovereignty. Two qualifications belong with that summary. First, the privacy policy keeps a general clause allowing transfers outside the European Economic Area where the destination offers an adequate level of protection or where appropriate safeguards such as Standard Contractual Clauses are in place; this is a standard clause and not a statement that transfers occur. Second, no subprocessor list is published, so the hosting claim rests on the vendor's own statements rather than on a verifiable chain of providers. The public website itself is served from a content delivery network, which says nothing about where the platform processes guest data.
Things to keep in mind
Risks and trade-offs to weigh before adopting Onsai.
- The site still publishes its former domain onsai.io across its sitemap, robots.txt, llms.txt, og:url and JSON-LD, while onsai.io in fact redirects to onsai.com; several of those declared URLs are stale
- The social image declared for sharing returns a 404, and the structured data points to a LinkedIn page that is not the publisher's own, the correct one appearing only in the site footer
- The site claims it was founded in October 2024, whereas the commercial register records the articles of association on 19 August 2024 and the actual incorporation on 3 December 2024
- Handing the guest's first point of contact to an autonomous agent shifts a genuinely relational part of hospitality onto software, and staff may lose the informal signals that phone contact used to give them
- Data sovereignty is asserted in marketing copy rather than evidenced: no security certification, no subprocessor list and no quantified retention period are published
- Because the agent writes directly into the property management system, a misunderstood call becomes a wrong booking, so the monitoring dashboard should be treated as an operational duty rather than a reporting nicety
- The published EUR 199 plan covers 100 calls; a property whose volume grows will move up a pricing ladder whose upper steps are not published anywhere
Setup & Integrations
Technical difficulty
Low for the hotel, because the work is done with the vendor rather than by the customer. Onsai announces a go-live within ten working days and includes two hours of personal onboarding, after which support runs by email. The hotel must supply access to its telephone system and a compatible property management system, such as Apaleo, Mews or Oracle Opera Cloud, plus the knowledge base content and the workflow rules. There is no self-service installation and no public API, so the schedule depends on the vendor rather than on in-house engineering.
Deployment
Integrations
Supported languages
Behind Onsai
Fundraising
Social
Resources
All the official URLs gathered for verification and reference.
Alternatives
Tools that compete with or complement Onsai.
Frequently asked questions
What exactly is agentic AI in Onsai's sense?
Can the voice agent actually take a booking?
Which languages does Onsai support?
How long does implementation take?
Where is guest data hosted?
How much does Onsai cost?
Is there a free plan or a free trial?
Does Onsai offer an API or a mobile app?
Does it work for a hotel group rather than a single property?
Is Onsai too large a solution for a small boutique hotel?
Should you pick Onsai?
Onsai is a focused, credible answer to a narrow and very real operational problem: hotel phones that ring unanswered. Rather than adapting a generic voice bot, the company has built agents trained on hospitality vocabulary and wired them into the property management system deeply enough to complete a booking during the call. That depth, together with Commission Check and Reservation Check, means the platform touches revenue and not only guest experience.
Two commitments set it apart in its market. The first is data sovereignty: open-source models, hosting in Germany, optional on-premise deployment and stated independence from US cloud providers, which will matter to European operators. The second is pricing transparency: an entry plan published at EUR 199 per month, billed per call rather than per room, in a market where quotes are usually hidden.
The reservations are equally clear. There is no public API, so a hotel group with its own IT cannot build on the platform independently. There is no permanent free plan and no self-service path: buying means signing. The published price, oddly, appears nowhere on a pricing page and has to be read on the comparison pages. The Email Agent is still announced rather than delivered. And despite a sales pitch built on security and sovereignty, the company claims no security certification whatsoever, publishes no subprocessor list and quantifies no retention period.
Onsai is also a young company, incorporated in December 2024 and funded with a little over EUR 1 million in 2025, with a handful of named hotel customers. The product looks well aimed and the traction is real; prospective buyers should simply match the maturity of the vendor, and the gaps in its published compliance evidence, against what their own procurement requires.
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