> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/no-data/webhooks-background-delivery-stopping/upgrade-api-version-for-delivery.md). # What's the recommended delivery method? Delivery instability is generally not specific to a destination like [Firebase](https://docs.tryterra.co/health-and-fitness-api/integration-setup/setting-up-data-destinations/firestore). * If you're on an older API version, **upgrading to the latest** improves event delivery speed, error handling, retries and consistency. The upgrade is handled Terra-side with no code changes and is backwards compatible. * After a successful connection, you may also need a [historical data request](https://docs.tryterra.co/health-and-fitness-api/managing-user-health-data/requesting-historical-data) to retrieve existing historical data. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.tryterra.co/faq/help-topics/no-data/webhooks-background-delivery-stopping/upgrade-api-version-for-delivery.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.