Privacy Policy
Last updated: March 2026
SoulTrack (https://soultrack.io) is operated by an individual operator based in Japan. This Privacy Policy explains what information we collect when you use our AI music generation service, how we use it, and your rights regarding that information. By using SoulTrack, you agree to the practices described in this policy. This policy is prepared in compliance with the Act on the Protection of Personal Information (個人情報保護法) of Japan. Because we use third-party services based in the United States (Vercel, Anthropic, and Replicate), your data may be processed outside Japan.
Information We Collect
We collect your IP address solely for the purpose of enforcing rate limits (3 tracks per day per IP address) for unauthenticated users; this data is stored in Vercel KV with a 24-hour time-to-live and is automatically deleted after that period. When you select a language using the language switcher, we store your preference in a browser cookie named NEXT_LOCALE; this cookie contains only a language code (e.g., 'en', 'ja') and no personally identifiable information. We use Vercel Analytics, a privacy-friendly analytics service that collects only aggregate page view statistics without additional tracking cookies, without tracking individual users, and without collecting any personally identifiable information (PII). Optionally, you may sign in to SoulTrack by providing your email address; if you do, your email address is transmitted to Resend (our email delivery provider) to send a magic-link sign-in email, and your email address and a session token are stored in Vercel KV to maintain your account. If you do not sign in, we do not collect your email address or any other personal information beyond the IP address and language-preference cookie described above.
How We Use Your Information
Your IP address is used exclusively to enforce the daily rate limit of 3 generated tracks per IP address and is not used for advertising, profiling, or any other purpose. Aggregate analytics data from Vercel Analytics is used solely to understand overall usage patterns and improve the service. The selections you make to generate music are processed by Anthropic's Claude API to create a descriptive music prompt, and then transmitted to Replicate's API to generate the audio; these transmissions are subject to Anthropic's and Replicate's own privacy practices respectively.
Third-Party Services
SoulTrack relies on the following third-party services: (1) Vercel, which provides hosting infrastructure and privacy-friendly analytics (no additional tracking cookies, no PII, aggregate data only) — see Vercel's privacy policy at https://vercel.com/legal/privacy-policy; (2) Anthropic, which powers the Claude AI model used to generate descriptive music prompts from your selections — your selections are processed by Anthropic's API, and Anthropic's privacy policy applies (https://www.anthropic.com/legal/privacy); (3) Replicate, which powers the MusicGen AI model — the generated music prompt is sent to Replicate's API to produce audio, and Replicate's privacy policy applies (https://replicate.com/privacy); (4) Resend, which provides email delivery for magic-link sign-in — your email address is transmitted to Resend when you choose to sign in, and Resend's privacy policy applies (https://resend.com/legal/privacy-policy). All four providers are based in the United States. We do not sell or share your information with any other third parties.
Data Retention
Tracks generated by unauthenticated users are stored in Vercel KV with a 24-hour time-to-live (TTL) and are automatically deleted after that period. Tracks saved to the library of an authenticated user are stored in Vercel KV indefinitely (without TTL) until the user explicitly deletes them. IP addresses used for rate limiting are stored in Vercel KV with a 24-hour time-to-live (TTL) as an anonymous counter key and are automatically deleted after that period; they are not linked to any personal profile. If you create an account, your email address and associated session data are stored in Vercel KV indefinitely until you request account deletion. The NEXT_LOCALE language-preference cookie has a 1-year lifetime in the browser and stores only a language code. Aggregate analytics data retained by Vercel Analytics does not contain personally identifiable information.
Your Rights
Under the Act on the Protection of Personal Information (個人情報保護法), you have the right to request disclosure, correction, addition, deletion, or suspension of use of your personal information held by us. Because we store only your IP address (as a rate-limit counter, deleted after 24 hours) and a language-preference cookie (containing only a language code), there is generally minimal personal data on file. For the operator's name and address, which may be required when submitting a formal personal information request under the Act, please contact us at the email address in the Contact section and we will provide these details promptly. If you have questions or concerns about your personal information, please contact us using the details provided in the Contact section below.
Contact
For any privacy-related inquiries, requests regarding your personal information, or questions about this Privacy Policy, you may contact us at contact@soultrack.io. We will endeavor to respond to your inquiry within a reasonable time (and in any event within 14 days for formal personal information requests under the Act on the Protection of Personal Information).