Since 1.86, the "login via QR code" feature does not work even if matrix-http-rendezvous-synapse is installed.

[YamatoRyou]

Description

I recently upgraded Synapse to 1.86 (and then to 1.87), but then found that the "Login via QR code" feature disappeared in the client (Element Desktop & Web).
Version number <= 1.85 is back to normal. I can't tell whether the fault is Synapse or matrix-http-rendezvous-synapse.

According to the usage given by https://pypi.org/project/matrix-http-rendezvous-synapse/, visit https://<myserver.com>/_synapse/client/org.matrix.msc3886/rendezvous Return HTTP 405 error.

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Steps to reproduce

n/a

Homeserver

Self-hosted

Synapse Version

Synapse 1.87.0

Installation Method

Docker (matrixdotorg/synapse)

Database

PostgreSQL 14.5

Workers

Single process

Platform

Synology DiskStation Manager 6.2.3 (Linux 3.10.105 x86_64)

Configuration

GET /_matrix/client/versions

{"versions":["r0.0.1","r0.1.0","r0.2.0","r0.3.0","r0.4.0","r0.5.0","r0.6.0","r0.6.1","v1.1","v1.2","v1.3","v1.4","v1.5","v1.6"],"unstable_features":{"org.matrix.label_based_filtering":true,"org.matrix.e2e_cross_signing":true,"org.matrix.msc2432":true,"uk.half-shot.msc2666.query_mutual_rooms":true,"io.element.e2ee_forced.public":false,"io.element.e2ee_forced.private":false,"io.element.e2ee_forced.trusted_private":false,"org.matrix.msc3026.busy_presence":false,"org.matrix.msc2285.stable":true,"org.matrix.msc3827.stable":true,"org.matrix.msc3440.stable":true,"org.matrix.msc3771":true,"org.matrix.msc3773":false,"fi.mau.msc2815":false,"fi.mau.msc2659.stable":true,"org.matrix.msc3882":false,"org.matrix.msc3881":false,"org.matrix.msc3874":false,"org.matrix.msc3886":true,"org.matrix.msc3912":false,"org.matrix.msc3981":false,"org.matrix.msc3391":false}}

---

homeserver.yaml

modules:
  - module: matrix_http_rendezvous_synapse.SynapseRendezvousModule
    config:
      prefix: /_synapse/client/org.matrix.msc3886/rendezvous

experimental_features:
  msc3882_enabled: true
  msc3882_ui_auth: false
  msc3886_enabled: true
  msc3886_endpoint: /_synapse/client/org.matrix.msc3886/rendezvous

Relevant log output

n/a

Anything else that would be useful to know?

Since the installation of matrix-http-rendezvous-synapse did not fail, and access to http://<myserver.com>/_synapse/client/org.matrix.msc3886/rendezvous did not give any description of the error log.

[hughns]

MSC3882 was approved and accepted into v1.7 of the Matrix spec.

v1.86 of Synapse added support for this new stable feature and removed support for the experimental feature.

These options are no longer valid:

  msc3882_enabled: true
  msc3882_ui_auth: false

The new stable options are detailed here:
https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#login_via_existing_session

[YamatoRyou]

MSC3882 was approved and accepted into v1.7 of the Matrix spec.

v1.86 of Synapse added support for this new stable feature and removed support for the experimental feature.

These options are no longer valid:

  msc3882_enabled: true
  msc3882_ui_auth: false

The new stable options are detailed here: https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#login_via_existing_session

The sorted out solution is:

1. matrix-http-rendezvous-synapse still needs to be installed.
2. Edit homeserver.yaml:
   Add the following content:

login_via_existing_session:
   enabled: true
   require_ui_auth: false
   token_timeout: "5m"

Delete the following (MSC3882 has become a stable feature, so removed from experimental_features):
From:

experimental_features:
    msc3882_enabled: true
    msc3882_ui_auth: false
    msc3886_enabled: true
    msc3886_endpoint: /_synapse/client/org.matrix.msc3886/rendezvous

To:

experimental_features:
    msc3886_enabled: true
    msc3886_endpoint: /_synapse/client/org.matrix.msc3886/rendezvous

The following remain as they are:

modules:
   - module: matrix_http_rendezvous_synapse.SynapseRendezvousModule
     config:
       prefix: /_synapse/client/org.matrix.msc3886/rendezvous

3. Restart Synapse.