fix(usage): Cursor account history loads about 4x faster

[t3dotgg]

Usage waits for every source before it shows anything. On a busy Cursor account, the Cursor history reader was nearly all of that wait: it asked for one 1,000-event page at a time, and each page takes about a second. A 30-day window with 36k events took about 46 s, close to the reader's 60 s deadline.

The reader now keeps up to six pages requested ahead of the one it reads. It still reads pages in order, so the count check, overlap reconciliation, end-of-history rule and "Sign in to Cursor again" result do not change. When the read ends, it cancels the requests still in flight. Krishna measured 45.9 s → 9.6 s on a real account with identical records.

This continues #14384 by @im-kvijay, whose commit is imported unchanged with its authorship. I could not update that PR's branch from here, so this PR carries it onto current main.

Proof: the new ordering test fails against main's reader and passes with this change. Lint, server typecheck and the 144 usage tests pass on current main.

Takeover and verification by Claude Opus 5.5 in Claude Code. Original change by @im-kvijay with Claude Opus 5.5 in Claude Code.

🤖 Generated with Claude Code

[macroscopeapp]

Approvability

Verdict: Approved at ddf404e

Macroscope's review found this PR approvable — This is a narrowly scoped performance improvement to Cursor history retrieval, with bounded concurrency, ordered consumption, cancellation, and tests covering the key runtime cases. Existing usage output and caller behavior remain unchanged.

No code changes detected at 23d29e2. Prior analysis still applies.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	5.0 KiB	5.0 KiB	0 B (0.0%)	6.8 KiB	✅
Codex	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.2 KiB	1.2 KiB	0 B (0.0%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	20.9 KiB	20.9 KiB	0 B (0.0%)	29.3 KiB	✅
Codex	Live turn messages	2	2	0 (0.0%)	8	✅
Claude	Total thread wire	5.0 KiB	5.0 KiB	0 B (0.0%)	6.8 KiB	✅
Claude	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.2 KiB	1.2 KiB	0 B (0.0%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	21.2 KiB	21.2 KiB	0 B (0.0%)	29.3 KiB	✅
Claude	Live turn messages	2	2	0 (0.0%)	8	✅

Baseline: 10e29a2 · PR result: 23d29e2 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[coderabbitai]

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• apps/server/src/usage/cursorUsageReader.test.ts
• apps/server/src/usage/cursorUsageReader.ts

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📝 Walkthrough

Walkthrough

readCursorAccountUsage now fetches up to six usage pages concurrently and consumes their results in page order. It aborts outstanding requests when reading exits. New tests cover request concurrency, record ordering, and failures from later pages.

Changes

Cursor usage pagination

Layer / File(s)	Summary
Concurrent page reads and cancellation apps/server/src/usage/cursorUsageReader.ts, apps/server/src/usage/cursorUsageReader.test.ts	The reader queues up to six page requests and consumes responses in page order. A shared abort signal cancels outstanding requests when reading exits. Tests check concurrency, ordered records, and later-page network and authorization failures.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Refactor

Sequence Diagram(s)

sequenceDiagram
  participant Reader as readCursorAccountUsage
  participant Requests as Cursor page requests
  participant Controller as AbortController
  Reader->>Requests: Start up to six page reads
  Requests-->>Reader: Return page results
  Reader->>Reader: Consume results in page order
  Reader->>Controller: Abort shared signal on exit
  Controller-->>Requests: Cancel outstanding requests

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Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to ddf40

The concurrent history reader preserves page order and the existing end-of-history behavior. No merge-blocking issue was established.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: faster Cursor account history loading through usage improvements.
Description check	✅ Passed	The description covers the problem, implementation, scope context, measured performance improvement, verification results, and agent attribution. It provides a linked related pull request but does not…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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