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The Developer API is part of the NexRex Data Portability Promise: if you build on it, we won’t pull the rug out from under you.

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Our commitment

  • Breaking changes are announced at least 90 days in advance, except where a security or legal emergency requires an immediate change.
  • We publish a version date on every response (X-API-Version, currently 2026-07-01). A breaking change ships under a new version date; the previous version keeps working through the notice window.
  • Additive changes are not breaking. New fields may appear on responses, and new endpoints may be added, at any time. Build your client to ignore unknown fields.

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What counts as breaking

  • Removing or renaming an endpoint, field, scope, or error code
  • Changing the type or meaning of an existing field
  • Tightening validation in a way that rejects previously valid requests
  • Reducing a rate limit

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Staying informed

Breaking-change notices are published on the Data Portability Promise page and its changelog. The machine-readable OpenAPI spec always reflects the current version — diff it to see exactly what changed.

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Current limitations

This is v1. Some capabilities are intentionally not yet available:
  • Read and export only — no write or propose endpoints, and no webhooks.
  • GPX / FIT / TCX export formats are not yet offered (CSV and JSON today).
  • Some raw vendor payloads may be restricted by the upstream provider’s terms and are not included in exports.