Schedule 3B: Enhanced Support (Enterprise)

Version 2.0, effective as of 5 February 2026

1. Overview

This Schedule sets out the terms for Enhanced Support (Enterprise) purchased separately from a product licence. Where support is included as part of a product licence (Avalonia Accelerate or Avalonia XPF), the support terms in the applicable Product Schedule govern.

2. Definitions

"Business Hours" means 08:00-20:00 Central European Time (CET) on Business Days.

"Critical Issue" means an Error that causes a production outage, a material loss of core functionality in a production system, or a security vulnerability with a credible risk of active exploitation, and for which no reasonable workaround exists.

"Designated User" means a single, distinct person for whom support has been purchased and who has been assigned a seat in the Customer Portal. A Designated User must hold, or be assigned under the Order Form, a valid licence for the supported Avalonia UI product or service.

"Response Time" means the period from when a support request is submitted until Avalonia UI provides a response that addresses (but does not necessarily resolve) the request.

"Support Portal" means Avalonia's web-based support interface for ticket submission and support-related services.

"Support Validity Term" means the fixed time period during which the Customer is eligible to receive Enhanced Support (Enterprise), with a minimum term of twelve (12) months.

"Technical Account Manager" means the Avalonia UI representative assigned as the Customer's primary point of contact for Enterprise Support.

3. General Support Terms

3.1 Services Provided

Subject to this Schedule and during the Support Validity Term, Avalonia UI will provide Designated Users with support for Avalonia via the Customer Portal and email ([email protected]).

Support is provided exclusively for projects written in C#. Avalonia UI does not offer support for applications built with F# or VB.NET.

3.2 Scope of Support

Avalonia UI will make commercially reasonable efforts to solve any Errors reported by Designated Users. Resolution may be provided through a later released version, a fix, a workaround, or other solution Avalonia UI deems reasonable.

Support is limited to issues specifically related to the functionality, integration, and behaviour of the Software as provided by Avalonia UI. Issues originating from third-party components, platforms, or frameworks outside Avalonia UI's control may receive guidance or workarounds at Avalonia UI's discretion, but Avalonia UI is not obligated to provide fixes for external components.

Support is limited to the product or service purchased. Avalonia UI does not provide general .NET support or advice on issues outside the scope of the purchased product or service. Support for one Avalonia UI product does not entitle the Customer to support for any other product; requests outside scope may be declined.

3.3 Support Limitations

Support will be aligned with the major version available at the time of purchase. If a new major version is released during the Support Validity Term, the Customer may seek support for both versions. Upon renewal, support is limited to the latest major version unless Extended Support is purchased.

Support is not provided for: Pre-Release Functionality; forks of Avalonia UI; Errors on unsupported platforms; hardware or OS-specific problems; or problems arising from improper use, accident, neglect, or modification.

3.4 Subscriber Obligations

All support requests relating to issues must provide detailed information to allow Avalonia UI to quickly and easily verify the problem.

To report an Error, the Designated User shall register the Error on the Support Portal using their Avalonia Account. Each support request must include:

A clear, detailed description of the problem;
Identification of the affected Avalonia UI package and version;
Operating environment information (OS, runtime, hardware platform);
A minimal, compilable test case (preferably under 500 lines);
Relevant screenshots or diagnostic content in standard formats (JPEG, PNG);
Attachments in .zip or .tar.gz format (executables and proprietary formats not accepted).

Failure to provide adequate information may relieve Avalonia UI from performing Support Services.

4. Enhanced Support (Enterprise)

4.1 Dedicated Support

Enterprise Enhanced Support provides dedicated support coverage, including a Technical Account Manager and real-time collaboration channels.

4.2 Unlimited Tickets (Fair Use)

Enterprise Enhanced Support includes unlimited tickets under normal usage patterns.

Avalonia UI monitors aggregate engineering hours. If the average engineering hours per seat for a customer exceeds 120% of the average across all other Enterprise customers over any consecutive three (3) month period, Avalonia UI may suspend response time commitments while reviewing the account.

Where continued support would result in material net loss, Avalonia UI may propose revised terms or terminate Support Services with thirty (30) days' written notice.

4.3 Response Times and SLAs

Standard Response Time for Errors and support requests will not exceed one (1) Business Day.

Critical Issues will have a Response Time not to exceed eight (8) Business Hours. If a Critical Issue is reported outside Business Hours, the Response Time clock begins at the start of the next Business Hour.

4.4 Communication Channels

Enterprise Enhanced Support is provided via Email ([email protected]), the Support Portal, and real-time Slack communication with Avalonia engineers.

4.5 Private Issue Tracker and Priority GitHub Issues

Enterprise Enhanced Support includes a private issue tracker dedicated to the Customer. Access is limited to Designated Users.

Avalonia UI will prioritize issues reported by Designated Users in Avalonia UI's public GitHub issue tracker, but does not guarantee resolution or timeframes.

4.6 Strategic Partnership Services

Enterprise Enhanced Support includes:

A dedicated Technical Account Manager;
An annual architectural audit with a written summary of findings and recommendations;
Quarterly technical check-ins;
Video consultations as needed, scheduled in advance; and
Product roadmap access at Avalonia UI's discretion.

4.7 Advanced Services

Enterprise Enhanced Support includes:

Emergency bug fixes and hot patches, where commercially reasonable;
LTS backporting for supported long-term support releases, where available;
Extended Linux support for Tier 2 and Tier 3 distributions, as specified in the Order Form or Avalonia UI documentation; and
Supply chain security attestation, including reasonable evidence of build integrity and component provenance.

4.8 Accelerate Enterprise Licence Included

Unless otherwise specified in the Order Form, each Enterprise Enhanced Support seat includes one Avalonia Accelerate Enterprise licence for the same Designated User for the duration of the Support Validity Term.

4.9 IP Indemnification

Avalonia UI's intellectual property indemnification obligations are as set out in Section 3.4 of the Master Terms.

5. Security Issues

5.1 Reporting

Security Issues must be marked as such in the Support Portal to ensure proper prioritisation.

5.2 Response Time

Security Issues are treated as Critical Issues for Response Time purposes.

5.3 Security Fix Delivery

Verified Security Issues will be fixed as soon as practically possible, dependent on severity. Patches for currently supported versions will be provided along with appropriate notifications.

5.4 Third-Party Security Issues

If a Security Issue is in a third-party library used in Avalonia UI, Avalonia UI will notify the relevant third party. When fixed, the new version will be included in a Maintenance Release. If no fix is available, Avalonia UI may provide documentation or a patch for the third-party library.

6. Extended Support

Extended Support extends the Support Validity Term for a version of Avalonia that is no longer generally supported.

Extended Support is mandatory for customers with active support agreements who continue to develop or maintain products on older Avalonia versions. It requires specifying the Avalonia version(s) and Platform(s) being used.

Extended Support is specific to the Customer's Avalonia Account and the identified versions and platforms.

7. Development Team Coverage

Support coverage must correspond to all individuals within the Customer's organisation who submit support requests or access Enhanced Support. Each such individual must be a Designated User.

Support may not be limited to a subset of licensed or supported users for the purpose of reducing seat count.

8. Fees and Payment

Support Fees are calculated based on the number of active Designated Users during the Support Validity Term, as set out in the Order Form.

Support agreements are invoiced annually in advance. Enterprise Enhanced Support may, by prior written agreement, be invoiced quarterly subject to a 10% administrative surcharge.

Enterprise Enhanced Support is available only for multi-seat agreements.

9. Term and Renewal

Support agreements have a minimum term of twelve (12) months.

Renewal is not automatic. Near the end of the term, Avalonia UI will contact the Customer to review coverage and send a renewal invoice. If the Customer does not renew, access to further support will end.

Avalonia UI has no obligation to offer renewal and may, in its sole discretion and for any reason, decline to renew Support Services. If Avalonia UI declines renewal, Support Services will end at the end of the then-current term.

10. Audit and Compliance

Avalonia UI may verify the Customer's compliance with these Support Terms, including the number of Designated Users covered by Enhanced Support.

Upon request, the Customer must provide written attestation of the total number of supported users, signed by an authorised representative.

If an audit reveals more supported users than are covered by Enhanced Support, the Customer shall promptly purchase additional Support seats and pay for the uncovered period at then-current rates.

End of Schedule 3B