API Terms of Use – Anonymous, Free and Pro Tiers

1. Parties

These API Terms of Use (“Terms”) constitute a legally binding agreement between Algebrakit B.V., a limited liability company incorporated under the laws of the Netherlands, with its registered office at Torenallee 20, 5617 BC Eindhoven, the Netherlands, registered with the Dutch trade register under number 61729396 (“Algebrakit”, “we”, “us”), and You, the individual or entity accessing or using the API (“You”, “User”).

2. Scope and Related Documents

2.1 The three documents

These Terms are one of three documents that together govern developer use of Algebrakit technology:

2.2 The Formula Editor

Standalone use of the Formula Editor for keyboard entry of mathematical expressions is governed by the Algebrakit Formula Editor — Free Use Licence and requires no account and no API key. These Terms apply to the Formula Editor only in respect of:

In the event of conflict between the Formula Editor — Free Use Licence and these Terms in respect of the API or the Handwriting Recognition service, these Terms prevail.

2.3 The SDKs

The SDKs are licensed as open source under the MIT Licence and are not part of the API. Use of the API made through an SDK is governed by these Terms in the same way as use made by any other means. The MIT Licence grants no right to use the API.

2.4 Corporate and institutional customers

These Terms do not apply to corporate or institutional customers that have entered into an Algebrakit Software as a Service Subscription Agreement. Where such an agreement is in force, that agreement and its Service Level Agreement govern that customer’s use of the API and prevail over these Terms in the event of conflict.

Users requiring contractually guaranteed uptime, service credits, deployment on the long-term support (LTS) environment, a data processing agreement, a dedicated account manager, custom terms, or on-site support should contact Algebrakit at sales@algebrakit.nl regarding a Corporate subscription. None of these is available at any developer tier.

2.5 Order of precedence

The Documentation and the pricing page at algebrakit.com/pricing are incorporated into these Terms by reference for the purpose of establishing tier thresholds, Rate Limits, functional scope, and Subscription Fees. In the event of conflict, the main body of these Terms prevails over the Documentation and the pricing page.

3. Definitions

API. The Algebrakit application programming interface, comprising the endpoints and server-side functionality made available by Algebrakit, including the Evaluation Engine, the Content Management System, and the Handwriting Recognition service. The API does not include the SDKs, which are licensed separately as open source.

API Key. A unique credential, public or private, that identifies the tier and authorises access to the API.

Anonymous Tier. Access to the API using a publicly available API key, requiring no account registration, subject to severe Rate Limits and to the functional scope published for that tier.

Content. Exercises, sessions, configurations, and other data created or stored by a User through the API.

Documentation. The technical documentation, integration guides, and usage instructions published at docs.algebrakit.com or such other address notified by Algebrakit from time to time.

Fair Use Policy. The policy set out in Section 13, governing acceptable levels of API usage on the Pro Tier.

Formula Editor. The Algebrakit Formula Editor web component, licensed separately under the Algebrakit Formula Editor — Free Use Licence.

Free Tier. Access to the API using a private API key issued to a registered account, subject to the Rate Limits and functional scope published for that tier.

Handwriting Recognition. The Algebrakit service that receives Stroke Data and returns a recognised mathematical expression.

Pro Tier. Paid access to the API using a private API key issued to a registered account, without fixed Rate Limits but subject to the Fair Use Policy, and sharable within a team.

Pro Tier. Paid access to the API using a private API key issued to a registered account, without fixed Rate Limits but subject to the Fair Use Policy, and sharable within a team.

Rate Limits. The request-volume thresholds applicable to the relevant tier, as published in the Documentation.

SDKs. The client libraries published by Algebrakit for calling the API, licensed under the MIT Licence.

Services. All functionality made available through the API, including the Evaluation Engine, the Web Components, the Content Management System, the Handwriting Recognition service, and related developer features.

Session Data. Data generated by the Services in connection with an exercise session, including responses and scoring results. Session Data does not include personally identifiable information of end users.

Stroke Data. The coordinate data describing handwritten input submitted to the Handwriting Recognition service.

Subscription Fee. The recurring fee payable by a Pro Tier User as published on the Algebrakit pricing page at the time of purchase and processed via Stripe.

Web Components. Algebrakit-provided browser components made available as part of the Services, including question-type components, some of which embed the Formula Editor.

4. Service Tiers

Algebrakit offers the following access tiers. Rate Limit thresholds, storage allowances, functional scope, and pricing are published at algebrakit.com/pricing and in the Documentation, and may be updated in accordance with Section 19.

TierKey typeCostRate limitsContentSupport and availability
AnonymousPublicFreeSevere limits, as publishedAlgebrakit-published exercise content only; no authoring or storageNo support; as is, as available
FreePrivateFreeStandard limits per accountLimited Content authoring and storage, as publishedNo support; as is, as available
ProPrivatePaid (Stripe)No fixed limits; Fair Use Policy appliesContent authoring and storage subject to Fair Use; sharable within a teamEmail support in business hours; best-effort availability, no service credits

Tiers differ in Rate Limits and functional scope, not in permitted purpose. Subject to the Rate Limits and functional scope of Your tier and to Section 7, these Terms do not restrict use of the API to non-commercial purposes, and You may deploy applications built on the API commercially at any tier.

Anonymous Tier access requires no account registration. By using any Algebrakit API endpoint with a public API key, You accept these Terms. Free and Pro Tier access requires creation of an account at algebrakit.com; acceptance of these Terms is confirmed by clicking the acceptance checkbox during account registration or tier upgrade.

5. Acceptance, Accounts and End Users

Algebrakit offers the following access tiers. Rate Limit thresholds, storage allowances, functional scope, and pricing are published at algebrakit.com/pricing and in the Documentation, and may be updated in accordance with Section 19.

5.1 Eligibility

You must be at least 18 years of age and have the legal capacity to enter into a binding agreement in order to create a Free or Pro account. If You register on behalf of a company, You represent that You have authority to bind that company to these Terms.

5.2 Eligibility

You agree to provide accurate and complete information when registering and to keep that information up to date. You are responsible for maintaining the confidentiality of Your API key(s) and for all activity that occurs under Your account.

5.3 Eligibility

Rate Limits on the Free Tier are applied per API key and, on the Anonymous Tier, per the mechanism published in the Documentation. Creating multiple accounts or using technical means to circumvent Rate Limits constitutes a material breach of these Terms.

5.4 Eligibility

The API is designed for integration into applications that may be used by learners, including minors. Algebrakit has no account relationship with Your end users, and no account relationship with anyone at the Anonymous Tier.

As between You and Algebrakit, You are responsible for compliance with all laws applicable to Your deployment, including any notice, consent, parental-permission, or age-verification requirements, and for any age-related restrictions in the jurisdictions in which Your application is made available. The eligibility requirement in Section 5.1 applies to the person or entity holding the account, not to end users of Your application.

6. Licence Grant

Subject to Your compliance with these Terms and, where applicable, payment of the Subscription Fee, Algebrakit grants You a limited, non-exclusive, non-transferable, non-sublicensable, revocable licence to:

This licence is not an open-source licence. It does not include any right to access, use, or receive the source code of the software underlying the API. All rights not expressly granted are reserved by Algebrakit.

6.1 Authorised Developers (Pro Tier)

A Pro Tier User may permit its employees and contractors (“Authorised Developers”) to use the API on its behalf, provided that it remains responsible for their compliance with these Terms. Authorised Developers may be added and removed through the account management portal. The Pro licence is scoped to a single organisation or individual; it may not be shared across legally separate entities without a Corporate subscription.

7. Restrictions

You shall not, and shall ensure that Your Authorised Developers do not:

8. Attribution

The Web Components display attribution to Algebrakit as part of their default rendering. You must not remove, obscure, overwrite, or suppress that attribution in any way, whether through CSS, JavaScript, wrapper elements, or any other technical means. This obligation applies at all tiers, including Anonymous Tier use.

Where You use the Formula Editor, the attribution requirement in Section 5 of the Algebrakit Formula Editor — Free Use Licence applies in addition.

9. Handwriting Recognition and Stroke Data

9.1 Server capacity and rate limits

Keyboard entry in the Formula Editor is entirely client-side and is not rate limited. The Handwriting Recognition feature transmits Stroke Data to Algebrakit servers for inference and therefore consumes Algebrakit server capacity. It is rate limited at every tier, including the Anonymous Tier.

The applicable limit is determined by the API key presented with the request or, where no key is presented, by the limits published for the Anonymous Tier. On the Pro Tier, fixed limits are replaced by the Fair Use Policy in Section 13. These obligations attach to use of the Handwriting Recognition service itself and apply whether the Formula Editor is loaded from Algebrakit’s CDN or from a self-hosted copy.

9.2 Degradation and withdrawal

Where a rate limit is reached, the Formula Editor continues to operate for keyboard entry and Handwriting Recognition becomes unavailable until the limit resets. This degradation is not a breach of these Terms by Algebrakit and is not a service failure.

Algebrakit may change, throttle, or withdraw the availability of Handwriting Recognition at the Anonymous and Free Tiers at any time. Where withdrawal or a material reduction is planned, Algebrakit will provide notice by publication in the Documentation and on the Algebrakit status page and, for registered Users, by email. The remaining functionality of the Formula Editor is unaffected.

9.3 Handling of Stroke Data

Stroke Data submitted to the Handwriting Recognition service is processed in memory and discarded immediately after a recognition result is returned. Successful submissions are not retained in any form.

The single exception is a recognition failure. Where the Handwriting Recognition service is unable to produce a recognition result for a submission, the stroke coordinates of that submission are retained for the purpose of improving the recognition model. In that case:

This Section applies identically at all three tiers, including anonymous use.

10. Data, Privacy and Security

10.1 Session Data

Algebrakit stores Session Data for up to 12 months from the date of last access, after which it is permanently and automatically deleted. Session Data may be retrieved during the retention period via the API using a session ID.

10.2 Personal data

The API is designed to operate without processing personally identifiable information (“PII”) of end users. You are responsible for ensuring that no PII is transmitted to the API, except as may be incidentally included in Content by You. You remain responsible for Your own compliance with applicable data protection laws, including the General Data Protection Regulation (GDPR). Algebrakit does not accumulate or retain end-user response data beyond what is technically necessary to maintain a session and to comply with the retention periods set out in these Terms.

Data processing agreements are not available at the developer tiers. If applicable data protection law requires a data processing agreement for Your intended use, contact Algebrakit about a Corporate subscription before using the Services in that context.

10.3 Privacy and Security Policy

Algebrakit’s Privacy and Security Policy, available at https://public.algebrakit.nl/privacy-v1.0, governs the handling of any data processed in connection with the Services and is incorporated into these Terms by reference.

10.4 Security

You shall keep Your API credentials confidential and shall promptly notify Algebrakit of any actual or suspected unauthorised access. Algebrakit may revoke or rotate credentials if it reasonably suspects a security breach.

11. Acceptable Use

You must not use the Services to transmit, process, or store any material that:

Algebrakit reserves the right to suspend access without prior notice if it reasonably believes that continued access poses an immediate risk of harm or legal liability. Where suspension is not an emergency, Algebrakit will provide notice and an opportunity to remedy in accordance with Section 18.

12. Pro Tier: Fees and Billing

12.1 Subscription

Pro Tier access is provided on a subscription basis. Subscription Fees, the billing cycle, and any applicable taxes are set out at algebrakit.com/pricing. Fees are exclusive of VAT and other applicable taxes, which are charged in addition where required by law. Fees are charged in advance at the start of each billing period. All payments are processed by Stripe; Your payment details are governed by Stripe’s terms of service. By upgrading to the Pro Tier You authorise Algebrakit to charge Your chosen payment method on a recurring basis until You cancel.

12.2 Company billing

You may enter a company name and VAT number during checkout. Where a valid EU VAT number is provided and the reverse charge mechanism applies, Algebrakit will issue invoices accordingly. You are responsible for providing accurate billing information.

12.3 Failed payment

If payment fails or is not received within 7 days of the due date, Algebrakit may suspend access to the Pro Tier without liability until the outstanding amount is settled.

12.4 Refunds

Except where required by applicable law, Subscription Fees are non-refundable. If You cancel Your Pro subscription, access continues until the end of the then-current billing period, after which Your account reverts to Free Tier Rate Limits and functional scope. No refund of prepaid Subscription Fees is due on termination by Algebrakit for Your breach.

12.5 Price changes

Algebrakit may adjust Pro Tier pricing on not less than 30 days’ notice by email to the address registered on Your account. Continued use of the Pro Tier after the effective date of a price change constitutes acceptance of the new price. If You do not accept the change, You must cancel before that date.

13. Fair Use Policy (Pro Tier)

The Pro Tier is offered without fixed Rate Limits. However, use must remain within the bounds of reasonable individual or team development activity. Algebrakit reserves the right to investigate and act upon usage patterns that, in its reasonable judgement, place disproportionate load on the infrastructure or suggest automated bulk use inconsistent with normal software development.

If Algebrakit determines that Your usage is in breach of this Fair Use Policy, it will:

Algebrakit will not apply fair-use enforcement in a discriminatory or arbitrary manner. Normal burst usage associated with testing, CI/CD pipelines, and team development is expressly permitted.

14. Availability, Support and Changes to the Services

14.1 Anonymous and Free Tiers

The Services are provided to Anonymous and Free Tier Users on an “as is” and “as available” basis. Algebrakit makes no uptime commitments for these tiers and may modify, suspend, or discontinue access at any time without notice. Technical support is not included; Documentation, integration guides, and community resources are available at docs.algebrakit.com.

14.2 Pro Tier availability

Algebrakit will use commercially reasonable efforts to maintain the availability of the Pro Tier Services. The Pro Tier runs on Algebrakit’s development environment, which receives weekly updates. While Algebrakit targets the equivalent of the availability standards set out in its standard Service Level Agreement, this is not a contractual guarantee at the Pro Tier. Planned maintenance will be announced at least 48 hours in advance via the Algebrakit status page and by email.

14.3 No service credits

No service credits apply at any developer tier. If You require contractually guaranteed uptime, service credits, and LTS-environment deployment, contact Algebrakit regarding a Corporate subscription.

14.4 Pro Tier support

Pro Tier Users receive email-based technical support during Normal Business Hours (Monday to Friday, 08:00–17:00 CET, excluding Dutch public holidays). Support is provided for issues relating to the API and the Services; it does not include general development consulting. Issues should be submitted via the support portal at https://helpdesk.support.algebrakit.com or by email to support@algebrakit.nl.

Algebrakit will use best efforts to acknowledge reported issues within the following target times. These are targets, not contractual commitments, and no service credit or other remedy attaches to them.

PriorityDescriptionTarget acknowledgement
P1Complete loss of service; API unavailableSame business day
P2Severe degradation; partial functionalitySame business day
P3Minor issue; workaround available2 business days
P4Documentation or cosmetic issue3 business days

You acknowledge that the Pro Tier does not include a dedicated account manager, an emergency telephone line, custom SLA negotiation, resolution-time commitments, or on-site support. Users requiring these services should contact Algebrakit about a Corporate subscription.

14.5 Modifications to the Services

Algebrakit may modify, update, or discontinue features of the API or the Services at any time. Where changes materially affect existing functionality, Algebrakit will provide reasonable advance notice via email or the Documentation.

15. Intellectual Property

15.1 Algebrakit IP

Algebrakit and its licensors own all intellectual property rights in and to the Services, the API, the software, the Documentation, the Web Components, the Formula Editor, and the Algebrakit exercise content library, including all source code, algorithms, and underlying technology. These Terms do not transfer any ownership to You and do not grant You any rights to use the source code of that software.

“Algebrakit” and related marks are trade marks of Algebrakit B.V. and may not be used without prior written consent, except to describe Your integration in a factually accurate manner.

Nothing in these Terms shall be construed as a waiver of Algebrakit’s intellectual property rights in the Services, the API, or any underlying technology, nor as a grant of any open source licence, save that the SDKs are separately published under the MIT Licence as described in Section 2.3.

15.2 Your Content and Your Products

You retain all intellectual property rights in and to Your Products, the Content You create through the Services, and any other content created by You, excluding the Algebrakit components embedded therein. You grant Algebrakit a limited, non-exclusive licence to store and process Your Content solely to the extent necessary to provide the Services to You.

16. Confidentiality

This Section applies to Free and Pro Tier Users. Each party may receive information that is confidential to the other (“Confidential Information”). Each party shall: (a) hold the other’s Confidential Information in confidence using at least the same degree of care as it uses for its own confidential information, and no less than reasonable care; (b) not disclose it to third parties without prior written consent; and (c) use it only for the purposes of these Terms.

For the avoidance of doubt, the source code, algorithms, and technical implementation underlying the API are Confidential Information of Algebrakit. These obligations do not apply to information that is or becomes publicly known without breach of these Terms, was already known to the receiving party, is independently developed, or is required to be disclosed by law or by a competent authority. This Section survives termination for a period of five (5) years.

17. Warranties and Limitation of Liability

Algebrakit warrants that it holds and will maintain all licences and permissions necessary to make the Services available under these Terms, and, in respect of the Pro Tier, that it will perform the Services with reasonable skill and care and substantially in accordance with the Documentation.

EXCEPT AS EXPRESSLY SET OUT IN THESE TERMS, THE SERVICES AND THE API ARE PROVIDED “AS IS”. ALGEBRAKIT DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. ALGEBRAKIT DOES NOT WARRANT THAT THE SERVICES WILL BE ERROR-FREE OR UNINTERRUPTED, OR THAT RESULTS OBTAINED THROUGH THE SERVICES WILL MEET YOUR REQUIREMENTS.

Nothing in these Terms excludes or limits Algebrakit’s liability for death or personal injury caused by its negligence, fraud or fraudulent misrepresentation, intentional misconduct (opzet) or gross negligence (grove schuld), or any liability that cannot be excluded under applicable Dutch law, including under Article 6:233 of the Dutch Civil Code.

Subject to the above:

You assume sole responsibility for any results obtained from use of the Services, for conclusions drawn from such use, and for any applications or products You build using the Services.

18. Term, Suspension and Termination

18.1 Duration

These Terms remain in force for as long as You access or use the Services. For Pro Tier Users, the agreement continues until the subscription is cancelled in accordance with these Terms.

18.2 Termination by You

You may cancel Your account at any time through Your account settings. For Pro Tier Users, cancellation takes effect at the end of the current billing period. Anonymous Tier Users may simply stop using the API; no notice is required.

18.3 Termination or suspension by Algebrakit

Algebrakit may suspend or terminate Your access:

18.4 Inactivity

Free Tier accounts that have not been accessed for 12 consecutive months may be deleted. Algebrakit will send a warning email to the registered address at least 30 days before deletion. Anonymous Tier access generates no account and is subject to no inactivity rule.

18.5 Effect of termination

19. Changes to These Terms, Pricing and Rate Limits

Algebrakit may update these Terms from time to time. If the changes are material, Algebrakit will notify registered Users by email at least 30 days before the new version takes effect. For Anonymous Tier Users, notice will be provided by publication on the Algebrakit website and in the Documentation. The current version is always available at algebrakit.com/terms. If You continue to use the Services after the effective date, You are deemed to have accepted the updated Terms. If You do not accept them, You must stop using the Services and may cancel Your account.

Algebrakit reserves the right to adjust the Rate Limits and functional scope applicable to the Anonymous and Free Tiers at any time. Where a reduction would materially affect existing usage, Algebrakit will provide at least 14 days’ notice via the Documentation and, for registered Users, by email. Changes to Rate Limits do not constitute a termination of these Terms. Pro Tier pricing changes are governed by Section 12.5.

20. Governing Law and Jurisdiction

These Terms and any dispute or claim arising out of or in connection with them, including non-contractual disputes or claims, shall be governed by and construed in accordance with the laws of the Netherlands. The parties irrevocably submit to the exclusive jurisdiction of the courts of Oost-Brabant, the Netherlands.

Nothing in this Section affects any right You may have as a consumer to bring proceedings in the courts of Your place of residence where applicable law so requires.

21. General

21.1 Entire agreement

These Terms, together with the Documentation and the Privacy and Security Policy incorporated by reference, constitute the entire agreement between You and Algebrakit with respect to the developer tiers and supersede all prior arrangements, representations, or understandings relating to the same subject matter. This Section does not limit the operation of the Algebrakit Formula Editor — Free Use Licence or the MIT Licence in respect of the matters those documents govern, as described in Section 2.

21.2 Severance

If any provision of these Terms is found to be invalid or unenforceable, that provision shall be modified to the minimum extent necessary to make it valid and enforceable while giving effect to the parties’ original intent, and the remaining provisions shall continue in full force and effect.

21.3 No waiver

No failure or delay by either party to exercise or enforce any right under these Terms shall constitute a waiver of that right.

21.4 Assignment

You may not assign or transfer Your rights or obligations under these Terms without Algebrakit’s prior written consent. Algebrakit may assign these Terms, in whole or in part, including in connection with a merger, acquisition, or sale of all or substantially all of its assets, on notice to You.

21.5 No partnership

Nothing in these Terms creates a partnership, joint venture, agency, or employment relationship between You and Algebrakit.

21.6 Force majeure

Algebrakit shall not be liable for any failure or delay in performing its obligations under these Terms to the extent that such failure or delay is caused by circumstances beyond its reasonable control, including acts of God, war, civil unrest, strikes, utility failures, internet disruptions, or failure of third-party cloud infrastructure (including AWS). Algebrakit will notify affected registered Users as soon as reasonably practicable of any such event.

21.7 Notices and contact

Notices under these Terms shall be in writing. Algebrakit may give notice by email to the address provided at registration or by posting to the developer portal; for Anonymous Tier Users, by publication on the Algebrakit website and in the Documentation. Notices to Algebrakit should be sent by email to legal@algebrakit.nl. For technical support, visit https://helpdesk.support.algebrakit.com.