Terms of Service

1. Description of Service

OnUML is an AI-assisted diagram platform for creating, editing, repairing, previewing, saving, and sharing diagram content. Depending on the feature, the service may support Mermaid, PlantUML, Draw.io, Mind Map, and related diagram workflows.

The service may include features such as:

• Generating diagram code from natural-language prompts
• Editing and previewing Mermaid, PlantUML, Draw.io, and Mind Map content
• Cloud project storage, Library and Workspace management, and sharing links
• Exporting diagrams in supported output formats
• AI-powered generation, repair, refinement, image-assisted understanding, and chat-based assistance

2. Accounts and Access

Some features of OnUML may be available without signing in, while others require an account. You are responsible for maintaining the confidentiality of your account credentials and for all activities that occur under your account.

You agree to provide accurate information when creating or maintaining an account. We may suspend or restrict access if we reasonably believe your account is being used in violation of these Terms or in a way that threatens the security or stability of the service.

3. Free and Paid Plans

OnUML offers both free and paid access tiers. Different plans may include different project capacity, Workspace capacity, collaboration, AI usage, and project management capabilities.

The Free plan generally includes core editing, previewing, saving, public sharing, and basic AI usage, subject to usage limits. Free users may be limited in daily free AI requests, the number of cloud projects per Workspace, the number of diagrams per project, and the number of Workspaces they may own.

When a Workspace reaches the Free plan project limit, you may be unable to create additional projects or save content as a new project in that Workspace. Existing projects are not automatically deleted, hidden, or made inaccessible because of that capacity limit; subject to your permissions, you may continue to preview, open, and edit existing projects.

Pro plans expand project management, Workspace, collaboration, and AI usage capabilities. Pro users generally receive higher or unlimited Workspace project capacity, a higher per-project diagram limit, expanded Workspace creation capacity, no daily limit on free-model requests, included monthly AI credits, and access to more complete AI diagram workflows such as syntax repair, image-assisted generation, or other advanced AI actions.

Project and Workspace capacity may be determined by the Workspace owner's plan status. Project limits are generally counted by Workspace rather than by the individual creator. If a member creates a project inside another user's Workspace, that project may count against the target Workspace's capacity rather than the member's personal project capacity.

Workspace ownership limits are generally counted by the Workspaces you own. Shared Workspaces that you join as a member do not count toward your owned Workspace limit. If a former Pro user downgrades to the Free plan and owns more Workspaces than the Free plan allows, all Workspaces owned by that user may be prevented from inviting additional members until the user reduces the number of owned Workspaces or upgrades again. Existing Workspaces are not automatically deleted, hidden, or locked solely because of this limit, and access remains subject to the applicable Workspace roles and permissions.

AI credits are usage add-ons for certain AI actions, such as diagram generation, syntax repair, image understanding, image-assisted generation, or premium model runs. If an AI action requires credits and your balance is insufficient, that action may not proceed until you purchase additional credits or receive additional included credits. Credits are used for AI calls and do not determine account-plan capacity such as project counts, diagram counts, Workspace counts, or Workspace collaboration limits.

Plan features, availability, usage limits, included credits, and eligibility rules may change over time. If we materially change pricing or paid-plan scope for future periods, we will provide reasonable notice through the service, billing flow, email, or other appropriate channels.

4. Billing, Renewal, and Cancellation

Paid subscriptions are billed in advance on the billing cycle you select, such as monthly or yearly, through supported payment providers. By purchasing a paid plan, you authorize us and our payment providers to charge the applicable subscription fees, taxes, and related charges to your selected payment method.

If a payment fails, we may retry the charge, suspend paid features, or downgrade your access until billing is resolved. You may cancel your subscription through the billing tools made available in the product when supported. Unless otherwise stated in the checkout or required by law, cancellation will take effect at the end of the current paid period and previously charged fees are non-refundable.

If your subscription is cancelled, expires, or cannot be renewed, your account may be downgraded to the Free plan. After a downgrade, existing content may remain accessible according to your permissions, but creating new projects, creating new Workspaces, inviting additional members, using certain AI actions, or otherwise expanding usage may be restricted under the Free plan limits.

5. Acceptable Use

You agree to use OnUML only for lawful purposes and in compliance with these Terms.

You must not:

• Use the service to create, store, or distribute illegal, harmful, or abusive content
• Upload or generate content that infringes intellectual property, privacy, or other rights
• Attempt to reverse engineer, scrape, overload, disrupt, or bypass service protections
• Use bots or automated workflows in a way that unreasonably burdens the platform
• Misrepresent generated output as verified professional, legal, or technical advice
• Use the service in violation of applicable export controls, sanctions, or local laws

We may investigate violations, remove content, refuse processing, limit features, suspend accounts, or terminate access where reasonably necessary to protect users, the platform, or legal compliance.

6. User Content and AI Output

You retain ownership of the content you upload, enter, or create in OnUML, including prompts, project content, and diagram source material, to the extent permitted by law. You represent that you have the necessary rights to submit and use that content.

You are responsible for reviewing AI-generated or AI-repaired output before using, publishing, sharing, or relying on it. AI responses may be incomplete, inaccurate, malformed, or unsuitable for your intended purpose. OnUML does not guarantee that generated diagrams, code, repairs, or analysis will be correct, secure, original, or fit for any specific use case.

You grant OnUML the limited rights necessary to host, process, display, transmit, and transform your content solely for operating, securing, improving, and supporting the service, consistent with our Privacy Policy.

7. Intellectual Property

The OnUML website, branding, software, interface design, service logic, and all related intellectual property rights belong to OnUML or its licensors. Except as expressly allowed by these Terms, you may not copy, distribute, sell, sublicense, or create derivative works from the service itself.

These Terms do not transfer ownership of OnUML technology to you. They only grant you a limited, revocable, non-exclusive right to use the service in accordance with these Terms.

8. Third-Party Services

OnUML may rely on third-party infrastructure and providers, including hosting, authentication, AI model providers, rendering services, analytics, payment processors, and file storage services. Your use of certain features may also be subject to the terms and policies of those third parties.

We are not responsible for outages, policy changes, pricing changes, or data handling practices of third-party services, except as required by applicable law.

9. Availability and Changes

We may update, modify, suspend, or discontinue any part of OnUML at any time, including features, model availability, project capacity, Workspace limits, AI usage limits, credit rules, pricing, integrations, and supported output formats. We will try to provide advance notice for material changes when reasonably practical, but some updates may be made immediately for security, legal, or operational reasons.

We do not guarantee that the service will always be available, uninterrupted, timely, secure, or error-free.

10. Termination

You may stop using OnUML at any time. We may suspend or terminate your access, with or without notice, if you violate these Terms, create legal or security risk, fail to resolve payment issues, or misuse the platform.

Upon termination, your right to use the service ends immediately. We may retain certain data as required for legitimate business purposes, security, fraud prevention, billing records, or legal compliance.

11. Disclaimers

OnUML is provided on an "as is" and "as available" basis. To the maximum extent permitted by law, we disclaim all warranties, whether express, implied, or statutory, including warranties of merchantability, fitness for a particular purpose, non-infringement, and availability.

We do not guarantee specific business outcomes, engineering correctness, legal compliance of generated content, uninterrupted uptime, or that the service will meet every workflow requirement.

12. Limitation of Liability

To the maximum extent permitted by law, OnUML and its operators, affiliates, licensors, and service providers will not be liable for any indirect, incidental, special, consequential, exemplary, or punitive damages, or for any loss of profits, revenue, data, goodwill, or business opportunities arising out of or related to your use of the service.

To the extent liability cannot be excluded, our total liability for claims arising out of or relating to the service will not exceed the total amount you paid to OnUML for the service during the 12 months preceding the event giving rise to the claim.

13. Changes to These Terms

We may update these Terms from time to time. When we make material changes, we may update the date at the bottom of this page and provide notice through the service or other appropriate channels. Your continued use of OnUML after updated Terms become effective means you accept the revised Terms.

14. Contact Us

If you have questions about these Terms, please contact us at support@onuml.com.