# Tendral Health API

> Clinicians verified against the national NPI registry, a versioned JSON API, and docs generated from the same OpenAPI document the API runs on.

Base URL: https://api.tendralhealth.com/v1. Every page below is Markdown; the whole set is in one file at https://developer.tendralhealth.com/llms-full.txt.

## Get started

- [Quickstart](https://developer.tendralhealth.com/docs/quickstart.md): Make a first call, read a response, and learn how errors and keys work.
- [Authentication](https://developer.tendralhealth.com/docs/authentication.md): Bearer keys, scopes, expiry, revocation and rotation without downtime.
- [Environments](https://developer.tendralhealth.com/docs/environments.md): Production and staging base URLs, keys, test data and going live.

## Concepts

- [Versioning](https://developer.tendralhealth.com/docs/versioning.md): What changes inside /v1, what counts as breaking, and release phases.
- [Errors](https://developer.tendralhealth.com/docs/errors.md): The error envelope and every error code, with what to do about each.
- [Rate limits](https://developer.tendralhealth.com/docs/rate-limits.md): Requests per key per minute, the headers, and handling 429.
- [Idempotency](https://developer.tendralhealth.com/docs/idempotency.md): Retry a write safely with an Idempotency-Key.
- [Pagination](https://developer.tendralhealth.com/docs/pagination.md): Cursor pagination and walking every page of a list.

## Early access

- [Surveys API](https://developer.tendralhealth.com/docs/early-access/surveys-api.md): Create and check surveys from JSON. In private preview; draft shape.

## Trust

- [Security & data](https://developer.tendralhealth.com/docs/security.md): PHI, what the platform holds, encryption, key handling and reporting an issue.

## Reference

- [API reference](https://developer.tendralhealth.com/reference.md): every public endpoint.
- [OpenAPI document](https://developer.tendralhealth.com/openapi.json): the machine-readable source the reference renders.
- [Changelog](https://developer.tendralhealth.com/changelog.md): dated changes; latest 2026-10-07.