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Merged
tulir merged 2 commits into from
Oct 8, 2025
Merged

MSC4326: Device masquerading for appservices #4326

tulir merged 2 commits into from
Oct 8, 2025

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@turt2live turt2live commented Aug 12, 2025 •
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Disclosure: I am Director of Standards Development at The Matrix.org Foundation C.I.C., Matrix Spec Core Team (SCT) member, employed by Element, and operate the t2bot.io service. This proposal is written and published with my role as a member of the SCT.

SCT Stuff:

MSC checklist

FCP tickyboxes

@turt2live turt2live changed the title MSC: Device masquerading for appservices MSC4326: Device masquerading for appservices Aug 12, 2025
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turt2live commented Aug 12, 2025 •
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MSCs proposed for Final Comment Period (FCP) should meet the requirements outlined in the checklist prior to being accepted into the spec. This checklist is a bit long, but aims to reduce the number of follow-on MSCs after a feature lands.

SCT members: please check off things you check for, and raise a concern against FCP if the checklist is incomplete. If an item doesn't apply, prefer to check it rather than remove it. Unchecking items is encouraged where applicable.

Checklist:

  • Are appropriate implementation(s) specified in the MSC’s PR description?
  • Are all MSCs that this MSC depends on already accepted?
  • For each new endpoint that is introduced:
    • Have authentication requirements been specified?
    • Have rate-limiting requirements been specified?
    • Have guest access requirements been specified?
    • Are error responses specified?
      • Does each error case have a specified errcode (e.g. M_FORBIDDEN) and HTTP status code?
        • If a new errcode is introduced, is it clear that it is new?
  • Will the MSC require a new room version, and if so, has that been made clear?
    • Is the reason for a new room version clearly stated? For example, modifying the set of redacted fields changes how event IDs are calculated, thus requiring a new room version.
  • Are backwards-compatibility concerns appropriately addressed?
  • Are the endpoint conventions honoured?
    • Do HTTP endpoints use_underscores_like_this?
    • Will the endpoint return unbounded data? If so, has pagination been considered?
    • If the endpoint utilises pagination, is it consistent with the appendices?
  • An introduction exists and clearly outlines the problem being solved. Ideally, the first paragraph should be understandable by a non-technical audience.
  • All outstanding threads are resolved
    • All feedback is incorporated into the proposal text itself, either as a fix or noted as an alternative
  • While the exact sections do not need to be present, the details implied by the proposal template are covered. Namely:
    • Introduction
    • Proposal text
    • Potential issues
    • Alternatives
    • Dependencies
  • Stable identifiers are used throughout the proposal, except for the unstable prefix section
    • Unstable prefixes consider the awkward accepted-but-not-merged state
    • Chosen unstable prefixes do not pollute any global namespace (use “org.matrix.mscXXXX”, not “org.matrix”).
  • Changes have applicable Sign Off from all authors/editors/contributors
  • There is a dedicated "Security Considerations" section which detail any possible attacks/vulnerabilities this proposal may introduce, even if this is "None.". See RFC3552 for things to think about, but in particular pay attention to the OWASP Top Ten.

@turt2live turt2live marked this pull request as ready for review August 12, 2025 04:06
@turt2live turt2live added proposal A matrix spec change proposal application services kind:core MSC which is critical to the protocol's success needs-implementation This MSC does not have a qualifying implementation for the SCT to review. The MSC cannot enter FCP. labels Aug 12, 2025
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turt2live commented Aug 12, 2025
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@turt2live turt2live Aug 12, 2025 •
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Implementation requirements are met through MSC3202, specifically this bit of Synapse and the listed appservice/bot usage.

@turt2live turt2live removed the needs-implementation This MSC does not have a qualifying implementation for the SCT to review. The MSC cannot enter FCP. label Aug 12, 2025
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turt2live commented Aug 12, 2025

As this is effectively blocking #4190 - let's get this through the process.

@mscbot fcp merge

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mscbot commented Aug 12, 2025 •
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Team member @mscbot has proposed to merge this. The next step is review by the rest of the tagged people:

Concerns:

  • inexplicable error code choice

Once at least 75% of reviewers approve (and there are no outstanding concerns), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for information about what commands tagged team members can give me.

@mscbot mscbot added proposed-final-comment-period Currently awaiting signoff of a majority of team members in order to enter the final comment period. disposition-merge labels Aug 12, 2025
@github-project-automation github-project-automation bot moved this to Tracking for review in Spec Core Team Workflow Aug 12, 2025
@turt2live turt2live moved this from Tracking for review to Ready for FCP ticks in Spec Core Team Workflow Aug 12, 2025
This was referenced Aug 12, 2025
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richvdh reviewed Aug 26, 2025
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richvdh commented Sep 2, 2025

Maybe not the biggest problem in the world, but to make clear why this hasn't received my tick:

@mscbot concern inexplicable error code choice

@mscbot mscbot added the unresolved-concerns This proposal has at least one outstanding concern label Sep 2, 2025
@turt2live turt2live added the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Sep 5, 2025
@tulir tulir requested a review from richvdh September 21, 2025 12:14
@turt2live turt2live removed the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Sep 30, 2025
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onestacked commented Oct 2, 2025

@richvdh Since the error code is not M_UNKNOWN_DEVICE can your concern be resolved?

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richvdh commented Oct 3, 2025

@mscbot resolve inexplicable error code choice

@mscbot mscbot removed the unresolved-concerns This proposal has at least one outstanding concern label Oct 3, 2025
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mscbot commented Oct 3, 2025

🔔 This is now entering its final comment period, as per the review above. 🔔

@mscbot mscbot added final-comment-period This MSC has entered a final comment period in interest to approval, postpone, or delete in 5 days. and removed proposed-final-comment-period Currently awaiting signoff of a majority of team members in order to enter the final comment period. labels Oct 3, 2025
@richvdh richvdh moved this from Ready for FCP ticks to In FCP in Spec Core Team Workflow Oct 3, 2025
@turt2live turt2live mentioned this pull request Oct 3, 2025
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turt2live commented Oct 3, 2025

Spec PR: matrix-org/matrix-spec#2221

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mscbot commented Oct 8, 2025

The final comment period, with a disposition to merge, as per the review above, is now complete.

@mscbot mscbot added finished-final-comment-period and removed disposition-merge final-comment-period This MSC has entered a final comment period in interest to approval, postpone, or delete in 5 days. labels Oct 8, 2025
@tulir tulir mentioned this pull request Oct 8, 2025
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@tulir tulir merged commit 2b15b10 into main Oct 8, 2025
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@tulir tulir added spec-pr-in-review A proposal which has been PR'd against the spec and is in review and removed finished-final-comment-period labels Oct 8, 2025
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tulir commented Oct 8, 2025

Merged 🎉

@tulir tulir added merged A proposal whose PR has merged into the spec! and removed spec-pr-in-review A proposal which has been PR'd against the spec and is in review labels Oct 8, 2025
@tulir tulir moved this from In FCP to Merged in Spec Core Team Workflow Oct 8, 2025
@zecakeh zecakeh mentioned this pull request Oct 10, 2025
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Michael-Ixo pushed a commit to ixoworld/synapse that referenced this pull request Oct 23, 2025
@MichaelPretorius
Merge tag 'v1.140.0' into ixo
748b7bc 
Deployments that make use of the
[synapse-s3-storage-provider](https://github.com/matrix-org/synapse-s3-storage-provider)
module must upgrade to
[v1.6.0](https://github.com/matrix-org/synapse-s3-storage-provider/releases/tag/v1.6.0).
Using older versions of the module with this release of Synapse will prevent
users from being able to upload or download media.

No significant changes since 1.140.0rc1.

- Add [a new Media Query by ID Admin API](https://element-hq.github.io/synapse/v1.140/admin_api/media_admin_api.html#query-a-piece-of-media-by-id) that allows server admins to query and investigate the metadata of local or cached remote media via
  the `origin/media_id` identifier found in a [Matrix Content URI](https://spec.matrix.org/v1.14/client-server-api/#matrix-content-mxc-uris). ([\element-hq#18911](element-hq#18911))
- Add [a new Fetch Event Admin API](https://element-hq.github.io/synapse/v1.140/admin_api/fetch_event.html) to fetch an event by ID. ([\element-hq#18963](element-hq#18963))
- Update [MSC4284: Policy Servers](matrix-org/matrix-spec-proposals#4284) implementation to support signatures when available. ([\element-hq#18934](element-hq#18934))
- Add experimental implementation of the `GET /_matrix/client/v1/rtc/transports` endpoint for the latest draft of [MSC4143: MatrixRTC](matrix-org/matrix-spec-proposals#4143). ([\element-hq#18967](element-hq#18967))
- Expose a `defer_to_threadpool` function in the Synapse Module API that allows modules to run a function on a separate thread in a custom threadpool. ([\element-hq#19032](element-hq#19032))

- Fix room upgrade `room_config` argument and documentation for `user_may_create_room` spam-checker callback. ([\element-hq#18721](element-hq#18721))
- Compute a user's last seen timestamp from their devices' last seen timestamps instead of IPs, because the latter are automatically cleared according to `user_ips_max_age`. ([\element-hq#18948](element-hq#18948))
- Fix bug where ephemeral events were not filtered by room ID. Contributed by @frastefanini. ([\element-hq#19002](element-hq#19002))
- Update Synapse main process version string to include git info. ([\element-hq#19011](element-hq#19011))

- Explain how `Deferred` callbacks interact with logcontexts. ([\element-hq#18914](element-hq#18914))
- Fix documentation for `rc_room_creation` and `rc_reports` to clarify that a `per_user` rate limit is not supported. ([\element-hq#18998](element-hq#18998))

- Remove deprecated `LoggingContext.set_current_context`/`LoggingContext.current_context` methods which already have equivalent bare methods in `synapse.logging.context`. ([\element-hq#18989](element-hq#18989))
- Drop support for unstable field names from the long-accepted [MSC2732](matrix-org/matrix-spec-proposals#2732) (Olm fallback keys) proposal. ([\element-hq#18996](element-hq#18996))

- Cleanly shutdown `SynapseHomeServer` object, allowing artifacts of embedded small hosts to be properly garbage collected. ([\element-hq#18828](element-hq#18828))
- Update OEmbed providers to use 'X' instead of 'Twitter' in URL previews, following a rebrand. Contributed by @HammyHavoc. ([\element-hq#18767](element-hq#18767))
- Fix `server_name` in logging context for multiple Synapse instances in one process. ([\element-hq#18868](element-hq#18868))
- Wrap the Rust HTTP client with `make_deferred_yieldable` so it follows Synapse logcontext rules. ([\element-hq#18903](element-hq#18903))
- Fix the GitHub Actions workflow that moves issues labeled "X-Needs-Info" to the "Needs info" column on the team's internal triage board. ([\element-hq#18913](element-hq#18913))
- Disconnect background process work from request trace. ([\element-hq#18932](element-hq#18932))
- Reduce overall number of calls to `_get_e2e_cross_signing_signatures_for_devices` by increasing the batch size of devices the query is called with, reducing DB load. ([\element-hq#18939](element-hq#18939))
- Update error code used when an appservice tries to masquerade as an unknown device using [MSC4326](matrix-org/matrix-spec-proposals#4326). Contributed by @tulir @ Beeper. ([\element-hq#18947](element-hq#18947))
- Fix `no active span when trying to log` tracing error on startup (when OpenTracing is enabled). ([\element-hq#18959](element-hq#18959))
- Fix `run_coroutine_in_background(...)` incorrectly handling logcontext. ([\element-hq#18964](element-hq#18964))
- Add debug logs wherever we change current logcontext. ([\element-hq#18966](element-hq#18966))
- Update dockerfile metadata to fix broken link; point to documentation website. ([\element-hq#18971](element-hq#18971))
- Note that the code is additionally licensed under the [Element Commercial license](https://github.com/element-hq/synapse/blob/develop/LICENSE-COMMERCIAL) in SPDX expression field configs. ([\element-hq#18973](element-hq#18973))
- Fix logcontext handling in `timeout_deferred` tests. ([\element-hq#18974](element-hq#18974))
- Remove internal `ReplicationUploadKeysForUserRestServlet` as a follow-up to the work in element-hq#18581 that moved device changes off the main process. ([\element-hq#18988](element-hq#18988))
- Switch task scheduler from raw logcontext manipulation to using the dedicated logcontext utils. ([\element-hq#18990](element-hq#18990))
- Remove `MockClock()` in tests. ([\element-hq#18992](element-hq#18992))
- Switch back to our own custom `LogContextScopeManager` instead of OpenTracing's `ContextVarsScopeManager` which was causing problems when using the experimental `SYNAPSE_ASYNC_IO_REACTOR` option with tracing enabled. ([\element-hq#19007](element-hq#19007))
- Remove `version_string` argument from `HomeServer` since it's always the same. ([\element-hq#19012](element-hq#19012))
- Remove duplicate call to `hs.start_background_tasks()` introduced from a bad merge. ([\element-hq#19013](element-hq#19013))
- Split homeserver creation (`create_homeserver`) and setup (`setup`). ([\element-hq#19015](element-hq#19015))
- Swap near-end-of-life `macos-13` GitHub Actions runner for the `macos-15-intel` variant. ([\element-hq#19025](element-hq#19025))
- Introduce `RootConfig.validate_config()` which can be subclassed in `HomeServerConfig` to do cross-config class validation. ([\element-hq#19027](element-hq#19027))
- Allow any command of the `release.py` script to accept a `--gh-token` argument. ([\element-hq#19035](element-hq#19035))

* Bump Swatinem/rust-cache from 2.8.0 to 2.8.1. ([\element-hq#18949](element-hq#18949))
* Bump actions/cache from 4.2.4 to 4.3.0. ([\element-hq#18983](element-hq#18983))
* Bump anyhow from 1.0.99 to 1.0.100. ([\element-hq#18950](element-hq#18950))
* Bump authlib from 1.6.3 to 1.6.4. ([\element-hq#18957](element-hq#18957))
* Bump authlib from 1.6.4 to 1.6.5. ([\element-hq#19019](element-hq#19019))
* Bump bcrypt from 4.3.0 to 5.0.0. ([\element-hq#18984](element-hq#18984))
* Bump docker/login-action from 3.5.0 to 3.6.0. ([\element-hq#18978](element-hq#18978))
* Bump lxml from 6.0.0 to 6.0.2. ([\element-hq#18979](element-hq#18979))
* Bump phonenumbers from 9.0.13 to 9.0.14. ([\element-hq#18954](element-hq#18954))
* Bump phonenumbers from 9.0.14 to 9.0.15. ([\element-hq#18991](element-hq#18991))
* Bump prometheus-client from 0.22.1 to 0.23.1. ([\element-hq#19016](element-hq#19016))
* Bump pydantic from 2.11.9 to 2.11.10. ([\element-hq#19017](element-hq#19017))
* Bump pygithub from 2.7.0 to 2.8.1. ([\element-hq#18952](element-hq#18952))
* Bump regex from 1.11.2 to 1.11.3. ([\element-hq#18981](element-hq#18981))
* Bump serde from 1.0.224 to 1.0.226. ([\element-hq#18953](element-hq#18953))
* Bump serde from 1.0.226 to 1.0.228. ([\element-hq#18982](element-hq#18982))
* Bump setuptools-rust from 1.11.1 to 1.12.0. ([\element-hq#18980](element-hq#18980))
* Bump twine from 6.1.0 to 6.2.0. ([\element-hq#18985](element-hq#18985))
* Bump types-pyyaml from 6.0.12.20250809 to 6.0.12.20250915. ([\element-hq#19018](element-hq#19018))
* Bump types-requests from 2.32.4.20250809 to 2.32.4.20250913. ([\element-hq#18951](element-hq#18951))
* Bump typing-extensions from 4.14.1 to 4.15.0. ([\element-hq#18956](element-hq#18956))
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