# API Version and Access Guidance

The Medsender developer documentation uses the direct API base `https://api.medsender.com/api/v2`. The `v2` segment is part of every documented endpoint path and should remain in generated clients and hand-written requests. The [OpenAPI description](/openapi.json) publishes this established base as its only server, and the [endpoint catalog](/docs/endpoints) lists the methods and relative paths available in the current documentation.

## Test and live credentials

API requests authenticate with a Bearer API key. Test keys begin with `sk_test_` and keep development activity separate from live keys, which begin with `sk_live_`. Send the selected key in the `Authorization: Bearer YOUR_API_KEY` header. The same authentication shape is declared in OpenAPI so generated tools know that credentials belong in the HTTP Bearer header.

After signing in to the developer portal, open the API Keys area to create and manage the keys available to your account. Start integration work with a test key and the documented examples, then use a live key only when the calling workflow is ready for live account data. Read the [authentication guide](/docs/authentication) before making the first request.

## Access help and documentation questions

If an account does not show the key access needed for a documented workflow, or if an example does not match an observed response, contact [support@medsender.com](mailto:support@medsender.com). Include the documentation page, HTTP method and path, whether a test or live key was used, and the request identifier when one is available. Do not include an API key, patient document, or other sensitive payload in a support message.