Re: Experimental did:cel Witness Service (open-source)

If there's compatibility, I don't see why the webvh information website
couldn't reference it. I'm unsure about creating a hard dependency in the
specification. We use a secure peer to peer DIDComm protocol for witness
requests in our implementation, and are unlikely to implement an HTTP API
interface in the foreseeable future. I believe other implementers have also
defined their API services for witnessing, which should be taken into
consideration.

We debated including an API definition in the witness/watcher service, and
opted to define only watchers because witness governance is outside of the
WebVH spec, and implementers shouldn't be restricted by special
infrastructure requirements. However as mentioned, I think providing a
reference API definition could be interesting.

Perhaps did:cel could also include a dependency on a witness DIDComm
protocol. This would also be interesting.

On Sun, Mar 1, 2026 at 4:40 PM Manu Sporny <msporny@digitalbazaar.com>
wrote:

> On Fri, Feb 27, 2026 at 11:51 AM Filip Kolarik <filip26@gmail.com> wrote:
> > I’m excited to share an experimental witness service
> >
> > While designed for did:cel, the service can also be used to witness
> arbitrary events, providing a lightweight, verifiable, and high-performance
> proof layer for other decentralized or event-driven applications.
>
> This is awesome, Filip! I really like the fact that it highlights a
> number of things:
>
> Oblivious witness services:
>
> 1. Can be simple and quick to build.
> 2. Can be cost effective to operate.
> 3. Can be lightning fast (with c14n templates).
> 4. Can leverage industry standard HSMs.
> 5. Can be generalized to any market vertical.
>
> Would you have any aversion to us writing down the API for the service
> in a spec? It feels like it should be a separate, really lightweight
> spec that both the CEL spec, and did:cel depend on. I'd love to see
> did:webvh depend on it as well, thoughts on that from the did:webvh
> folks?
>
> -- manu
>
> --
> Manu Sporny - https://www.linkedin.com/in/manusporny/
> Founder/CEO - Digital Bazaar, Inc.
> https://www.digitalbazaar.com/
>
>