These Terms of Service apply to the Tontaube Developer API and Web Dashboard. If you are looking for the Terms of Use for our B2C Mobile App, please click here.

API Terms of Service

Version: 19 March 2026 (Beta)

Welcome to Tontaube! The following Terms of Service (hereinafter “ToS”) govern your access to and use of our AI-based text-to-speech Application Programming Interface (hereinafter “API”).

Please read these ToS carefully. They govern the contractual relationship regarding the use of the API between Cremer & Cremer Technologies UG (haftungsbeschränkt), Herderstraße 22, 12163 Berlin, Germany (hereinafter “Provider,” “we,” or “us”) and the registered user (hereinafter “User” or “you”).

Merchant of Record: All financial transactions, billing, and payment processing for access to the API are handled by our authorized Merchant of Record, Paddle (Paddle.com Market Limited or its affiliates). By purchasing credits, you also agree to Paddle’s Checkout Terms.

1. Scope of Application and User Classification

1.1 These ToS apply to all contracts for the use of the API. Deviating terms and conditions of the User shall not apply unless we have expressly agreed to their validity in writing.

1.2 Consumer (§ 13 BGB): A consumer is any natural person who enters into a legal transaction for purposes that are predominantly outside their trade, business, or profession.

1.3 Entrepreneur (§ 14 BGB): An entrepreneur is a natural or legal person, or a partnership with legal capacity, who acts in the course of their commercial or self-employed professional activity.

1.4 The rules in these ToS apply to both Consumers and Entrepreneurs unless a clause explicitly states that it applies only to one specific group.

1.5 Minimum Age: The User must be at least 18 years of age or have the verifiable consent of a legal guardian to use the API.

2. Definitions

  • “API” – The programmatic interface provided by us that allows the User to send text and receive synthetic audio.
  • “API Key” – A unique authentication token provided to the User to access the API.
  • ”Credits” – A prepaid monetary balance denominated in US Dollars (USD) that is consumed when making API requests.
  • ”Usage-Based Plan” – The standard billing model under which the User tops up their Credit balance via Paddle and consumes Credits on a pay-as-you-go basis.
  • ”Enterprise Plan” – A custom billing and service arrangement individually negotiated between the Provider and the User.
  • “Input” – All text, SSML, or parameters the User transmits to the API.
  • “Output” – The synthesized audio files generated by the API from the Input.
  • “Voice Sample” / “Cloned Voice” – Audio recordings provided by the User to create a custom synthetic voice profile via the API.

3. Description of Services, Beta Status, and AI Disclaimer

3.1 Scope: The Provider grants the User access to a RESTful API for text-to-speech conversion.

3.2 Beta Phase & “As Is” Provision: The API is currently in a “Beta” phase. The Provider provides the API strictly on an “as is” and “as available” basis. We expressly disclaim any Service Level Agreements (SLAs) or specific uptime guarantees. Unexpected downtime, latency spikes, or emergency maintenance may occur without prior notice. During the Beta phase, features, pricing, rate limits, and supported voices may change significantly. The Provider does not guarantee backward compatibility during the Beta phase. The Beta phase ends when the Provider publicly designates the API as generally available (“GA”). We may perform scheduled maintenance and will endeavour to notify Users in advance where practicable.

3.3 Probabilistic Nature of AI: The API utilizes probabilistic machine learning models. The User acknowledges that deviations, mispronunciations, varying pacing, or omissions in the Output may occur. The Provider does not guarantee that the Output will be completely error-free or perfectly suited to the User’s specific use case.

3.4 API Changes: We reserve the right to deprecate endpoints, modify the API schema, or update the underlying AI models at any time. During the Beta phase, we will provide reasonable advance notice of breaking changes via email or technical notices. Once the API reaches General Availability (GA), we will provide at least 30 days’ advance notice of breaking changes. Changes required for security, legal compliance, or the prevention of abuse may take effect immediately. It remains the User’s sole responsibility to update their software to maintain compatibility.

4. Access, Security, and Payment

4.1 Account Registration: To use the API, the User must create an account and provide accurate and complete registration information. The User is obligated to keep their account data up to date. The User is solely responsible for all activity conducted through their account.

4.2 API Keys: The User is solely responsible for maintaining the confidentiality of their API Keys. The User is financially and legally responsible for all Credit consumption and actions taken using their API Key, even if compromised by a third party.

4.3 Plans & Purchasing Credits: The API is available under two plans:

  • Usage-Based Plan: The User tops up their Credit balance via Paddle. A minimum top-up amount may apply as displayed at checkout. Credits are deducted based on the API pricing published in the documentation.

  • Enterprise Plan: Billing, usage limits, and service terms are governed by a separate written agreement between the Provider and the User. In the event of a conflict, the terms of the Enterprise agreement shall prevail over these ToS.

4.4 Consumption, Depletion & Rate Limits: Credits are consumed based on API usage (e.g., per character). If a User on the Usage-Based Plan depletes their Credit balance, API requests will be rejected (e.g., 402 Payment Required or 429 Too Many Requests) until the balance is topped up. The Provider may impose rate limits on API usage. Current rate limits are published in the API documentation.

4.5 No Refunds: Except as explicitly required by mandatory law or the terms of our Merchant of Record (Paddle), all purchases are final and non-refundable. For full details, including the statutory right of withdrawal for EU Consumers, technical error credits, and how to submit a request, please refer to our Refund Policy.

4.6 Credit Validity: Purchased Credits do not expire and remain valid until consumed or until the User’s account is terminated in accordance with Section 10.

5. Right of Withdrawal (Only for Consumers)

5.1 Statutory Right: If the User is a Consumer (§ 13 BGB), they generally have a statutory 14-day right of withdrawal.

5.2 Expiration for Digital Content (Waiver): The User expressly consents that the Provider will begin the performance of the contract (providing API access and Credits) before the expiry of the 14-day withdrawal period. The Consumer acknowledges that by granting this consent, they lose their statutory right of withdrawal as soon as the execution of the contract begins (e.g., when the API Key is activated or the first API call is made).

5.3 Entrepreneurs: If the User is an Entrepreneur (§ 14 BGB), no statutory right of withdrawal exists.

6. Intellectual Property, Rights of Use & Restrictions

6.1 Rights to Input and Output: The User retains all rights to their Input. Upon full payment of the required Credits, the Provider assigns to the User all exploitable usage rights to the generated Output (audio files) for private and commercial purposes.

6.2 Operating License to Provider: The User grants the Provider a necessary, technically limited right to process, store, and transmit the Input solely to generate the Output and maintain the API.

6.3 No Training: The User is strictly prohibited from using the API, the Output, or any related
metadata to train, fine-tune, develop, or improve any competing AI model, text-to-speech engine, or generative AI service.

7. Acceptable Use Policy (AUP) & Voice Cloning

7.1 Prohibited Use: The User must not use the API for unlawful or abusive purposes. It is strictly prohibited to generate:

  • Hate speech, defamation, or content that glorifies violence;
  • Deepfakes, non-consensual audio impersonations, or synthetic audio intended to deceive listeners about the speaker’s true identity;
  • Material for scam calls, robocalling fraud, or phishing;
  • Content that circumvents biometric security systems.

7.2 Voice Cloning Restrictions: If the API is used to clone the voice of a natural person, the User warrants that they hold the explicit, documented consent of the speaker in writing. The Provider reserves the right to request proof of such consent at any time. This consent requirement does not apply to purely synthetic voices generated entirely by the API without reference to a natural person’s voice. The User must not use Voice Cloning to impersonate another person without consent, deceive third parties, or violate personality rights. The User shall indemnify and hold the Provider harmless against all claims, damages, and costs arising from the User’s unauthorized use of a third party’s voice.

7.3 Sensitive Personal Data: The User should avoid transmitting special categories of personal data under Art. 9 GDPR — such as health or medical data, biometric data (other than Voice Samples submitted for Voice Cloning), racial or ethnic origin, political opinions, religious beliefs, or government-issued identification numbers — as unstructured text in API requests unless strictly necessary for the User’s use case. Where such data is transmitted, the User is solely responsible for ensuring a valid legal basis under Art. 9 GDPR and for documenting it accordingly.

7.4 AI Transparency: Where required by applicable law — including the EU AI Act (Regulation (EU) 2024/1689) — the User must clearly disclose to recipients that audio content was generated by artificial intelligence. The User must not remove or circumvent any AI-origin metadata embedded in the Output by the Provider.

7.5 Zero-Tolerance Suspension: In the event of a breach of this AUP, the Provider reserves the right to immediately and permanently revoke the User’s API Keys and suspend their account without prior notice and without a refund.

8. Data Protection & DPA (Auftragsverarbeitungsvertrag)

8.1 General Privacy: The processing of the User’s own personal data (e.g., account details) is governed by our Privacy Policy.

8.2 B2B Data Processing: If the User is an Entrepreneur (§ 14 BGB) and transmits personal data of third parties (e.g., their end-users’ names or PII within the Input text) to the API, the Provider acts as a Data Processor. In this case, the parties shall enter into the Provider’s standard Data Processing Agreement (DPA) according to Art. 28 GDPR, which is available at [DPA URL]. By using the API to process third-party personal data, the User accepts the terms of the DPA. A current list of sub-processors is available in Schedule 3 of the DPA.

8.3 Voice Data Retention & Deletion: Voice Samples uploaded by the User are stored only as long as necessary to maintain the User’s custom voice profile. The User may request deletion of their Voice Samples and associated voice profiles at any time by contacting the Provider. Upon account termination, all Voice Samples and derived voice profiles are permanently deleted within 30 days.

9. Liability (Haftung)

9.1 Unlimited Liability: The Provider is liable without limitation for damages caused by intent or gross negligence, and for injury to life, body, or health.

9.2 Liability for Entrepreneurs (§ 14 BGB): For slightly negligent breaches of essential contractual duties (cardinal duties), the Provider’s liability is limited to the foreseeable damage typical for the contract. In no event shall the Provider be liable to an Entrepreneur for indirect damages, consequential damages, or loss of profit.

9.3 Liability for Consumers (§ 13 BGB): For Consumers, the statutory liability rules apply.

9.4 Force Majeure: The Provider is not liable for API failures resulting from force majeure, third-party cloud provider outages, or cyber-attacks outside our control.

10. Term and Termination

10.1 Ordinary Termination: The User may terminate their account at any time by ceasing use of the API and requesting account deletion. The User is advised to exhaust their Credit balance before requesting account deletion. Any remaining Credit balance expires upon termination without refund, unless mandatory law requires otherwise.

10.2 Termination for Cause: Either party may terminate the contract for good cause. Good cause for the Provider includes, in particular, a breach of the Acceptable Use Policy (Sec. 7) or a payment default.

11. Final Provisions

11.1 Governing Law: German law applies, excluding the UN Convention on Contracts for the International Sale of Goods (CISG). For Consumers, mandatory consumer protection provisions of their country of residence remain unaffected.

11.2 Jurisdiction: If the User is an Entrepreneur, a legal entity under public law, or a special fund under public law, the exclusive place of jurisdiction is Berlin, Germany.

11.3 Severability: Should any provision of these ToS be wholly or partially invalid or unenforceable, the remainder of the contract remains effective.

11.4 Contact: For questions regarding these ToS, please contact us at legal@craitech.io.