I am the author of the now-frozen mxhsd project [1] and its resurected version, Gridepo [2]. I have contributed several times to the specification, reported issues for the past two years and still, to this day, I can confirm that it is not possible to implement a Matrix server with the current specification that can talk to the reference implementation.
Most fundamental problem: synapse doesn't sign the events like the spec tell us to do it, making every event invalid. Whatever you sent that is spec compliant will be refused by synapse.
So talking "synapse" is possible. Talking Matrix and be able to federate with the ecosystem is not. I wish people would not blindly believe what a for-profit is saying, especially one that is in full control of the said protocol, and start checking for themselves.
I'm not aware of a bug in how synapse signs events, and whilst it's possible there's a bug there, we can't fix stuff which we're unaware of which hasn't been disclosed. (Max would probably claim he can't disclose because he's been banned from our Github for consistently being obstructive; unfortunately this is a case in point).
In terms of "don't blindly believe what a for-profit is saying, especially one that is in full control of the said protocol", I'd agree, were it true. However:
* These days the protocol is controlled entirely by the non-profit Matrix Foundation.
* The majority (3 out of 5) of the Foundation's directors have zero affiliation to New Vector, the company that the core Matrix set up to try to keep the project funded.
* We're announcing the final board once formally appointed; due in the next few weeks.
Meanwhile, it's also true to say that you shouldn't believe the skewed perspective of a disgruntled ex-community member with a chip on their shoulder, who is trying to plug their hostile fork: https://news.ycombinator.com/item?id=19473694.
Most fundamental problem: synapse doesn't sign the events like the spec tell us to do it, making every event invalid. Whatever you sent that is spec compliant will be refused by synapse.
So talking "synapse" is possible. Talking Matrix and be able to federate with the ecosystem is not. I wish people would not blindly believe what a for-profit is saying, especially one that is in full control of the said protocol, and start checking for themselves.
[1]: https://github.com/kamax-matrix/mxhsd [2]: https://gitlab.com/kamax-io/grid/gridepo