# Choosing HTTP message signature versions

HTTP message signatures are an evolving Internet standard. Their development is managed as an Internet Engineering Task Force (IETF) draft.

## Supported versions

The exact version of the IETF draft you need to implement is as follows:

| Use case | Recommended | Supported |
|  --- | --- | --- |
| API Calls (HTTP requests *to* Upvest) | v15 | v15, v6 |
| Webhooks (HTTP requests *from* Upvest) | v6 | v6 |


## Research and choose

We strongly advise using the versions in the "Recommended" column, older, supported versions should be considered deprecated.

If you require more information about the different drafts, you can find the documents here:

- [The IETF draft for HTTP Message Signatures v15](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-message-signatures-15).
- [The IETF draft for HTTP Message Signatures v6](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-message-signatures-06).


Based on this information, and our recommendation above you should now know which versions you plan to implement.

## Next steps

Armed with this knowledge your ready to progress.

We suggest that you now proceed by taking a look at the Python examples. Return to the ["Implementing HTTP Signatures"](/products/tol/getting_started/http_signatures) tutorial.