Matrix Spec Support

Current Matrix spec/event support tracked for the bundled Matrix plugin.

Scope:

• code-backed today-state only
• plugin behavior only; not a claim of full Matrix spec coverage
• update this file when adding or removing Matrix event/spec support

Legend:

• in: inbound handling
• out: outbound send/edit/emit
• tools: CLI/action/runtime tooling built on that surface

Support Matrix

Surface	Spec / event ids	Support	Notes	Evidence
Core messages	m.room.message	in/out/tools	base text/media message surface	src/matrix/send/types.ts, src/matrix/actions/messages.ts
Rich text	org.matrix.custom.html	out	Markdown rendered to Matrix HTML	src/matrix/send/formatting.ts
Replies	m.in_reply_to	in/out	reply relation support	src/matrix/send/formatting.ts
Edits	m.replace	in/out/tools	Matrix edit flow; edit body uses * <text> fallback format	src/matrix/send/types.ts, src/matrix/draft-stream.test.ts
Threads	m.thread	in/out/tools	thread send, routing, session/thread policy	src/matrix/send/types.ts, src/matrix/monitor/types.ts, src/matrix/monitor/threads.test.ts
Direct rooms	m.direct	in/out/tools	DM routing, cache, repair, outbound target selection	src/matrix/send/types.ts, src/matrix/sdk.ts, src/matrix/send/targets.test.ts, src/matrix/direct-management.test.ts
Reactions	m.reaction, m.annotation	in/out/tools	send, summarize, inbound reaction routing	src/matrix/reaction-common.ts, src/matrix/monitor/reaction-events.test.ts
Read receipts	m.read	out	sent on inbound message receipt	src/matrix/sdk.ts, src/matrix/monitor/handler.ts
Typing	typing API	out	typing keepalive while reply runs	src/matrix/sdk.ts, src/matrix/send.ts, src/matrix/monitor/handler.ts
Mentions	m.mentions	in/out/tools	stable mention metadata on sends/edits/media captions/poll fallback text	src/matrix/send/formatting.ts, src/matrix/monitor/mentions.ts, src/matrix/send.test.ts
Mention link compat	https://matrix.to/#/...	in/out	emit + validate visible-label mentions in formatted HTML	src/matrix/format.ts, src/matrix/monitor/mentions.ts
Polls	m.poll.start, m.poll.response, m.poll.end	in/out/tools	stable poll create/read/vote/summary flow	src/matrix/poll-types.ts, src/matrix/actions/polls.ts, src/matrix/poll-summary.ts
Poll compat	org.matrix.msc3381.poll.start, org.matrix.msc3381.poll.response, org.matrix.msc3381.poll.end	in/out	unstable poll compat still emitted/parsed where needed	src/matrix/poll-types.ts, src/matrix/send.test.ts
Poll relations	m.reference	in/out/tools	poll votes/results linked to root poll event	src/matrix/poll-types.ts, src/matrix/actions/polls.ts, src/matrix/poll-summary.ts
Extensible text fallback	org.matrix.msc1767.text	in/out	poll text fallback/compat	src/matrix/poll-types.ts
Voice messages	org.matrix.msc3245.voice	out	voice-bubble marker on compatible audio sends	src/matrix/send/media.ts, src/matrix/send/types.ts
Voice audio metadata	org.matrix.msc1767.audio	out	duration metadata for voice sends	src/matrix/send/media.ts, src/matrix/send/types.ts
Location	m.location, geo:	in	inbound parse to text/context; no outbound location send tracked here	src/matrix/monitor/types.ts, src/matrix/monitor/location.ts, src/matrix/monitor/handler.ts
E2EE room events	m.room.encrypted	in/out/tools	encrypted event hydration, decrypt, encrypted media send	src/matrix/monitor/types.ts, src/matrix/sdk.ts, docs/channels/matrix.md
Encrypted media previews	file, thumbnail_file	out	encrypted thumbnails for encrypted image events	src/matrix/send/media.ts, docs/channels/matrix.md
Device verification	m.key.verification.*, m.key.verification.request	in/tools	request/ready/start/SAS/done/cancel notices and CLI flows	src/matrix/monitor/verification-utils.ts, src/matrix/monitor/events.test.ts, docs/channels/matrix.md
Streaming/live markers	org.matrix.msc4357.live	out	live draft/edit markers for partial streaming	src/matrix/send/types.ts, src/matrix/send.ts, src/matrix/draft-stream.ts

Explicit MSCs In Use

These MSCs are explicitly referenced in the plugin today:

• MSC3381: polls
• MSC1767: extensible-events fallback fields used for polls and voice metadata
• MSC3245: voice message marker
• MSC4357: live streaming marker

Evidence:

• src/matrix/poll-types.ts
• src/matrix/send/media.ts
• src/matrix/send/types.ts
• src/matrix/draft-stream.ts

Non-goals

This file does not claim:

• full client-server API coverage
• full room-state/event coverage inherited from matrix-js-sdk
• outbound support for any surface not listed above

If a new Matrix feature lands, add a row with:

1. exact event/spec id
2. support shape (in, out, tools)
3. at least one code path proving it

Missing / Candidate Specs

Recommended next additions, prioritized by user-visible value and closeness to current code:

Priority	Surface	Spec / event ids	Why add it	Current gap
high	Sticker messages	m.sticker	stable spec; common client surface; we already classify sticker attachments on read paths	no explicit inbound m.sticker event handling and no outbound sticker send path
high	Outbound location messages	m.location, geo_uri	stable spec; docs already say Matrix supports location, but current implementation is inbound-only	no outbound location send/action API
medium	Private + richer read markers	m.read.private, m.fully_read	stable spec; better privacy and cleaner read-state behavior than public-only m.read	current code only sends public m.read receipts
medium	Thread-aware receipts	m.read with thread_id	stable spec; better alignment with Matrix thread UX	current receipt send path has no thread_id support
medium	Unread markers	m.marked_unread	stable spec; useful for operator workflows and room triage tooling	no room account-data support for unread markers
low	Emote messages	m.emote	stable spec; easy parity win for bots/action tools	no explicit send/action support
low	Poll close parity	m.poll.end, org.matrix.msc3381.poll.end	completes the poll lifecycle on a surface we already parse	plugin parses poll-end events but does not expose an outbound close flow
low	Animated media metadata	info.is_animated on m.image / m.sticker	newer stable metadata; helps clients decide whether to fetch/render animated originals	media info builders do not populate animation metadata

Why these are listed

• m.sticker is a stable spec surface in the latest Matrix Client-Server API, and the plugin already has partial sticker awareness in message summarization.
• m.location is a stable spec surface in the latest Matrix Client-Server API. The plugin currently parses inbound location events from geo_uri, but does not send them.
• m.read.private, m.fully_read, and threaded receipts are stable read-marker/read-receipt surfaces in the latest Matrix Client-Server API. The plugin currently posts plain m.read receipts only.
• m.marked_unread is a stable room account-data surface in the latest Matrix Client-Server API and would be useful if Matrix actions grow more operator/client-like room triage controls.
• m.emote is a stable message type and a relatively small addition compared with the items above.
• m.poll.end is already represented in local poll types, so exposing a close-poll send/tool flow is a contained follow-up.
• info.is_animated is a smaller metadata-parity item, but easy to miss once sticker support exists.

Probably not worth prioritizing here

• VoIP / m.call.*: valid Matrix spec area and a plausible future direction here, just not a near-term priority relative to messaging, receipt, and room-state gaps.

Gap Evidence

• sticker partial only: src/matrix/media-text.ts
• location inbound only: src/matrix/monitor/location.ts, src/matrix/monitor/handler.ts
• public receipt only: src/matrix/sdk.ts, src/matrix/send.ts, src/matrix/monitor/handler.ts
• poll-end constants only: src/matrix/poll-types.ts
• no animation metadata emit: src/matrix/send/media.ts

External Spec References

• latest Matrix Client-Server API: https://spec.matrix.org/latest/client-server-api/index.html
• m.sticker: https://spec.matrix.org/latest/client-server-api/#msticker
• m.location: https://spec.matrix.org/latest/client-server-api/#mlocation
• receipts and read markers (m.read.private, m.fully_read, m.marked_unread): https://spec.matrix.org/latest/client-server-api/#receipts