feat(events): add mergify events, a timeline over the activity log

[jd]

The activity log carries ~45 event types — the action.queue.* family,
the workflow actions, ci_insights., command., queue pauses,
scheduled freezes — and almost none of it was reachable from the CLI,
so agents hand-rolled curl against a contract they did not know.

Add events as a new top-level noun over the shared client:

mergify events                       # whole repo, last 24h
mergify events --pr 1740 --since 7d
mergify events --type action.queue.leave --type command.queue
mergify events --pr 1740 --json      # raw events, newest first
mergify events --limit 20            # newest 20, and the header says so

One command over a filter covers every type; there is deliberately no
command per event type. Two details carry the lesson #1747 taught:

• The header always states the window (PR #1740 · 6 events · 2026-07-29 21:00 → 2026-07-30 21:00 UTC), so an empty result reads
  as "nothing in the last 24h" and never as "nothing ever" — that
  ambiguity is the bug this removes. The empty case names the range
  and the retention: No events for PR #1740 between <from> and <to> UTC. / Retention is 90 days; try --since 90d. (the hint is
  omitted when the query already covered the full retention).
• --since cannot express a window the API would reject: the
  duration parser enforces the 93-day cap as a usage error carrying
  the fix, and the 24h default is applied by the CLI and stated, not
  inherited silently from the API.

The human timeline reads oldest-first with a dim date row wherever
the calendar date changes, and a best-effort summary per line
(queue name, draft PR number, abort/dequeue codes, merged, command
author) that degrades to nothing on types this CLI has never seen.
--json emits one document echoing the query (repository,
pull_request, received_from, received_to) plus size and the
raw events newest-first, unknown fields intact.

Verified against the live API on Mergifyio/mergify-cli: the full
queue lifecycle of #1747 (enter → checks_start → checks_end → leave
merged), a 30-day repo-wide query paginating to completion (806
events over 9 pages, newest-first), the --type filter, and the empty
case naming its window.

Docs: README command list, a new mergify-events agent skill, the
mergify-merge-queue skill now routes "whole lifecycle" questions to
mergify events instead of curl, and AGENTS.md maps the new group.

Fixes MRGFY-8363.

Co-Authored-By: Claude Fable 5 noreply@anthropic.com

Depends-On: #1759

[jd]

This pull request is part of a Mergify stack:

#	Pull Request	Link
1	refactor(queue): port queue show's dequeue diagnosis onto mergify-events	#1759
2	feat(events): add mergify events, a timeline over the activity log	#1760	👈

[mergify]

Merge Protections

🔴 2 of 7 protections blocking · waiting on 👀 reviews

	Protection	Waiting on
🔴	👀 Review Requirements	👀 reviews
🔴	🔎 Reviews	👀 reviews
🟢	⛓️ Depends-On Requirements	—
🟢	🤖 Continuous Integration	—
🟢	Enforce conventional commit	—
🟢	📕 PR description	—
🟢	🚦 Auto-queue	—

🔴 👀 Review Requirements

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• #approved-reviews-by>=2

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  • author = dependabot[bot]
  • author = mergify-ci-bot
  • author = renovate[bot]

🔴 🔎 Reviews

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• #review-requested = 0

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• #review-requested = 0
• #changes-requested-reviews-by = 0
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---

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🟢 ⛓️ Depends-On Requirements

Requirement based on the presence of Depends-On in the body of the pull request

• depends-on = Mergifyio/mergify-cli#1759 [⛓️ refactor(queue): port queue show's dequeue diagnosis onto mergify-events #1759]

🟢 🤖 Continuous Integration

• all of:
  • check-success=ci-gate

🟢 Enforce conventional commit

Make sure that we follow https://www.conventionalcommits.org/en/v1.0.0/

• title ~= ^(fix|feat|internal|docs|style|refactor|perf|test|build|ci|chore|revert|ui)(?:\(.+\))?!?:

🟢 📕 PR description

• body ~= (?ms:.{48,})

🟢 🚦 Auto-queue

When all merge protections are satisfied, this pull request will be queued automatically.

[jd]

Revision history

#	Type	Changes	Reason	Date
1	initial	b8c7237		2026-08-05 12:18 UTC
2	rebase	b8c7237 → 263ea5e (rebase only)		2026-08-05 12:18 UTC
3	rebase	263ea5e → fdda9fe (rebase only)		2026-08-06 08:58 UTC

[mergify]

A predecessor in this stack was just merged, but I couldn't auto-rebase this PR: there's a conflict that needs manual resolution.

Conflict in: Cargo.lock, crates/mergify-events/Cargo.toml, crates/mergify-events/src/lib.rs (replayed onto 6bacff82).

Resolve with mergify stack sync && mergify stack push.

[mergify]

@jd this pull request is now in conflict 😩

[jd]

Rebased onto main — no content change.

The base of this stack, #1758, merged this morning as 8bb025c, which left this PR CONFLICTING. The stack is restacked on the new trunk and the conflict is gone.

263ea5e → fdda9fe — compare

cargo test --workspace, cargo fmt --check and cargo clippy --workspace --all-targets are clean on the rebased tip, and the commit below (#1759) was re-verified standalone — each commit is its own PR with its own CI.