API Terms of Use & Developer Agreement

Hifiverse.io — Last updated: 7 May 2026 · Version 1.0

Quick summary

• Four tiers: Free Developer (1,000 calls/month, non-commercial only); Starter API €99/month (10,000 calls); Pro API €499/month (100,000 calls, full dataset, up to 5 applications); Enterprise custom (1M+ calls, SLA, dedicated support).
• Alliance and Enterprise dealer subscribers receive bundled API allowances per their Dealer Agreement.
• You may not redistribute, resell or rebuild Hifiverse data products from our API.
• You may not use the API to circumvent the Marketplace, the subscription paywall, or any rate limit.
• Attribution required on every page where API data is shown.
• We can revoke API keys for breach without notice.

1. About this Agreement

This API Terms of Use & Developer Agreement ("API Agreement") governs your use of Hifiverse's application programming interfaces, software development kits, webhook services and developer tooling (collectively, the "API"). It is between you (the "Developer") and Timelapse Games EOOD.

Documentation lives at developers.hifiverse.io.

2. The four API tiers

Bundled API access for dealers. Alliance subscribers receive 10,000 calls/month for inventory-sync and storefront-management purposes, not for general application development.

3. Eligibility

You may apply for an API key if you hold an active Hifiverse account, are at least 18 years old (or authorised to act for a business), agree to this API Agreement, and your application does not infringe Hifiverse's rights or those of any third party.

For paid tiers we may ask for additional information about the application, use case, volume forecast and deployment environment.

4. Issuance and use of API keys

Each key is associated with a specific application and account. You may not:

• share your API key publicly (in client-side JavaScript, a public GitHub repository, or mobile-app binaries that can be decompiled);
• use a single key for multiple applications when the tier requires separate applications;
• create additional keys to evade a tier's rate limit — this is itself a breach.

You must rotate keys promptly when a developer with access leaves your organisation, when a key may have been compromised, or when we ask you to rotate.

5. The data you may access

Free Developer. Public Price Index reference data (model, category, condition-grade buckets, median price); public editorial article metadata; search endpoint with rate-limited results. No personal data, no individual-listing data, no user data.

Starter API. Free Developer data plus full Price Index detail (per-condition sub-grades, dispersion, regional breakdowns), full editorial body where syndication-licensed, and aggregated Marketplace metrics.

Pro API. Starter data plus historical Price Index series with full granularity, dealer-storefront metadata for partners that have opted in to syndication, advanced search filters, and the curated catalogue.

Enterprise. Pro data plus data licensed under your Enterprise contract, which may include manufacturer residual-value reports, derived analytics and white-label endpoints.

We do not expose at any tier: personal data of users; individual-listing detail with seller identity; private messages between buyers and sellers; Authentication reports not made public by the customer; moderation data; DAC7 or DSA Article 30 data.

6. Rate limits and headers

Rate limits are enforced per minute and per month. Each response carries:

• X-Hifiverse-RateLimit — per-minute limit for your key.
• X-Hifiverse-Remaining — calls remaining in the current minute.
• X-Hifiverse-Reset — timestamp when the per-minute counter resets.
• X-Hifiverse-Monthly-Remaining — calls remaining in the current monthly cycle.

When you exceed a limit, we return HTTP 429. Spamming retries against a 429 is itself a violation; back off and follow the headers.

We may adjust rate limits at any time for service reliability. We give at least 30 days' notice of a permanent reduction.

7. Permitted and prohibited uses

Permitted at any tier (subject to data-access limits):

• Building an end-user app that helps audiophiles track their gear and check valuations.
• Embedding Price Index references into a third-party site, with attribution.
• Inventory synchronisation between a dealer's POS or ERP and the dealer's Hifiverse storefront.
• Research and journalism (including by independent researchers under the Free Developer tier).
• Building a dealer-side trade-in calculator using Price Index references.
• Custom analytics for an Enterprise customer's own internal use.

Prohibited uses at every tier, without exception:

• Rebuilding Hifiverse's data products — constructing a competing price index, a competing collection-tracker, or any data product that materially substitutes for Hifiverse.
• Marketplace circumvention — scraping contact details from listings, harvesting a separate marketplace, operating a buyer-poaching service, or bypassing the subscription paywall.
• Resale of raw data — reselling or redistributing raw Hifiverse data, including by repackaging as a CSV download, an Excel export or a partner data feed, except where Enterprise terms specifically permit redistribution.
• AI-model training where data is unlicensed — using the API to scrape data for training third-party machine-learning models. Specific licences for ML training are negotiated under the Data Licensing Master Agreement.
• Operating an unauthorised analytics dashboard that shows Hifiverse data alongside scraped data from other platforms.
• Spam — using the API to facilitate unsolicited bulk communications.
• Circumventing rate limits, geographic restrictions, paywalled features or moderation.
• Reverse-engineering the API beyond the narrow rights in EU Directive 2009/24/EC.
• Building a competing service that takes the entirety of the Hifiverse value proposition and packages it under another brand.

8. Attribution

Every page or screen where API data is shown to an end user must include:

Data from Hifiverse — hifiverse.io

Attribution must be visible (not screen-reader-only), placed near the data it attributes, and link back to the relevant Hifiverse page. For dealer-side use that does not surface Hifiverse data to end users (e.g., internal inventory sync), external attribution is not required.

9. Changes to the API

Notice periods:

• Additive changes (new endpoints, new fields): no notice required; documented in the changelog.
• Backwards-compatible changes: documented in the changelog at the time of release.
• Deprecation (an endpoint will be removed): minimum 6 months advance notice via the changelog and Deprecation / Sunset HTTP headers.
• Breaking changes without deprecation (security fixes, regulatory mandates): notice as soon as practicable.
• Removal of a paid tier: minimum 90 days notice with right to refund prepaid amounts.

10. Service level (SLA)

For Free Developer, Starter and Pro tiers: best-efforts uptime. We do not credit fees for individual outages.

For Enterprise tiers (default SLA unless varied by order form):

• 99.5% monthly uptime for the production endpoints listed in the order form.
• Service credits of 5% of the monthly fee for each 0.5 percentage point below the SLA, capped at 50% of the monthly fee.
• Response times: 4 hours Critical, 24 hours High, 72 hours Normal.

11. Security and your obligations

You must: store API keys securely (never in client-side code or version control); use TLS for all calls; validate inputs and sanitise outputs; apply security patches promptly; notify us at info@hifiverse.io within 72 hours of a security incident affecting Hifiverse data.

12. Personal data and your privacy obligations

Where your application processes personal data of users, you are the controller of that data and must: have your own privacy policy; have a lawful basis for each processing activity; honour data-subject rights; keep records of your processing.

For applications that act on behalf of Hifiverse users (e.g., a dealer inventory-sync tool), we may enter a data-processing agreement under GDPR Article 28.

13. Intellectual property

We grant you a limited, non-exclusive, non-transferable, non-sublicensable, revocable licence to use the API solely for the purpose of operating the application registered with your API key. Your application is your IP.

14. Suspension and termination

We may suspend or revoke your API key without notice for breach of this API Agreement, breach of the Acceptable Use Policy, non-payment, security incidents arising from your application, or conduct creating reputational or legal risk for Hifiverse.

For non-emergency breaches, we will, where practicable, give you a warning and a 7-day opportunity to cure before revocation.

On termination: your API key is revoked immediately; you must stop displaying Hifiverse API data within 30 days (delete cached data, remove embedded widgets, decommission integrations).

15. Liability

Section 12 of the Terms of Service applies. Our aggregate liability for all claims arising under or connected with the API in any 12-month period is limited to the greater of (a) the API fees you actually paid us in the preceding 12 months, or (b) €100. The API is provided as is and as available.

16. Indemnification

You indemnify Hifiverse against any third-party claim arising from your application, including claims that your application infringes a third party's IP rights, breaches data-protection law, violates consumer-protection law, causes harm to end users, or breaches this API Agreement.

17. Governing law and jurisdiction

Bulgarian law. The exclusive forum for disputes is the Sofia City Court, Sofia, Bulgaria, except where mandatory consumer-protection law of the Developer's place of residence gives the Developer a right to sue in their own courts.

18. Changes to this Agreement

For changes that materially affect existing Developers, we give 30 days' notice.

Contact

• Email: info@hifiverse.io (subject: "API — Support", "API — Enterprise Sales", "Security Disclosure")
• Postal: Timelapse Games EOOD, Bulgaria