Platforms and Events

ChatEvent currently treats four platforms as the explicit support scope. push / pull no longer carry product semantics; they may only appear as legacy coarse acquisition modes. Event meaning is expressed by source + action/kind + target; target is a carrier chain, not just a label.

Support matrix

Platform	Official capability	Primary acquisition	Common action kinds
Zulip	Official REST API and event queue	event_queue, api_cursor	message.created, message.updated, reaction.added, reaction.removed, mention.created, topic.updated
Discourse	Official REST API and webhooks	webhook, api_cursor	topic.created, post.created, reply.created, post.edited, post.deleted, mention.created, reaction.added
Gitea	Official REST API and repository/org webhooks	webhook, api_cursor	push, commit.pushed, issue.opened, issue.closed, issue.commented, pull_request.opened, pull_request.updated, pull_request.merged, release.published
GitHub	Official REST/GraphQL API and webhooks	webhook, api_cursor	push, commit.pushed, issue.opened, issue.closed, issue.commented, pull_request.opened, pull_request.synchronize, pull_request.closed, pull_request.merged, workflow_run.requested, workflow_run.in_progress, workflow_run.completed, release.published

Field semantics

Field	Meaning
source	Platform id such as discourse.
target	Compatibility/display subscription scope such as category:agent-runs, stream:chatevent-practice/topic:real-loop, or repo:ChatArch/ChatEvent.
scope	Structured subscription carrier target with type, key, display, url, parent, and metadata, e.g. repo, PR, or topic.
actions	Structured action selectors derived from event_kinds by default; can store kind, object_type, verb, and metadata.
kind	Platform action such as reply.created.
capture_mode	Acquisition mechanism such as webhook, event_queue, or api_cursor.
tags / labels	Filtering, grouping, or routing hints; they do not define the platform action.

Discourse first posts and replies

Discourse official webhooks may send post_created for both the first topic post and later replies. ChatEvent normalizes them with post.post_number:

• post_number == 1 → post.created
• post_number > 1 → reply.created

The official webhook event name comes from the X-Discourse-Event header; the ChatEvent endpoint reads that header before normalization.

Actions and carrier target chains

A platform action can attach to different hierarchy levels. ChatEvent keeps target types and actor roles open-ended: each platform action catalog declares suggested target types, and each stored event records the actual target chain plus an optional initiator role.

Platform	Subscription scope example	Event target chain example
Zulip	stream:team/topic:release	zulip_stream:team → zulip_topic:team/release → message:123
Discourse	category:agent-runs or topic:22	discourse_topic:22 → discourse_post:35
GitHub/Gitea	repo:ChatArch/ChatEvent	repo:ChatArch/ChatEvent → pull_request:ChatArch/ChatEvent#4 → issue_comment:1234

The Observatory Platform actions panel shows action kind → target types; opening an Event Stream detail shows the concrete Action target and Target chain.