.well-known configuration

A .well-known/matrix/client file is required to be served to allow clients to discover the authentication service.

If no .well-known/matrix/client file is served currently then this will need to be enabled.

If the homeserver is Synapse and serving this file already then the correct values will already be included when the homeserver is configured to use MAS.

If the .well-known is hosted elsewhere then org.matrix.msc2965.authentication entries need to be included similar to the following:

  "m.homeserver": {
    "base_url": "https://matrix.example.com"
  "org.matrix.msc2965.authentication": {
    "issuer": "https://example.com/",
    "account": "https://auth.example.com/account"

For more context on what the correct values are, see here.