fix(usage): report incomplete transcript scans

[shivamhwp]

Usage summaries could omit unreadable transcripts while claiming complete coverage. Scans now preserve readable records, report partial coverage for every nested directory or file failure, and distinguish missing roots from failed reads. Failed reads retain cached records for recovery; incomplete walks cannot evict unseen files.

Buckets now carry their source directory index. The shared merge selects the healthiest copy of each physical directory without counting other accounts from that environment again. Deduplication spans files within each source directory. Contract v6 retains v4/v5 summaries when their buckets map unambiguously to a source; web, desktop and mobile flag ambiguous older summaries as requiring an update.

Fixes #5798. Based on main 20363c32c9bfdbf49c2716ef11d1f18483fcc01b. Codex cumulative-counter reconciliation in #5800 remains separate in #11322.

Validation: 61 focused reader, service, aggregation and merge tests pass, including disappearing nested directories, cache recovery, account attribution, reversed scan health and partially overlapping sources. Server, shared, web and mobile typechecks and scoped lint pass. Earlier Linux permission checks verified recovery from real access failures. Windows/macOS filesystem behavior and a new integrated UI pass remain unverified.

Internal Fable refinement remains pending after the final authorized retry failed. Human coverage and billing review remains required. No merge requested.

Implemented and tested with GPT-6 through Codex in T3 Code.

Summary by CodeRabbit

• Bug Fixes
  • Usage scans now distinguish complete, partial, missing, and failed transcript directories.
  • Reports identify unavailable or incomplete data instead of treating read failures as empty transcripts.
  • Incomplete scans preserve previously cached files.
  • Failed transcript files are excluded from usage totals and ownership calculations.
  • Usage from separate sources remains distinct, preventing duplicate or misattributed totals.
  • Ambiguous older usage summaries are excluded from compatibility checks.
  • Complete data is prioritized over partial, missing, or failed results when multiple sources are available.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This change alters production transcript scanning, token/cost aggregation, cross-environment deduplication, and compatibility handling across server and clients. Its cross-layer metering impact and new scan-state logic exceed the scope of a small self-contained fix.

No code changes detected at 13c1d2f. 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	13.5 KiB	13.6 KiB	+67 B (+0.5%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.0 KiB	7.0 KiB	0 B (0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.5 KiB	6.6 KiB	+67 B (+1.0%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	57.0 KiB	57.1 KiB	+88 B (+0.2%)	66.4 KiB	✅
Codex	Live turn messages	8	10	+2 (+25.0%)	21	✅
Claude	Total thread wire	13.6 KiB	13.6 KiB	−42 B (−0.3%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	0 B (0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.6 KiB	6.5 KiB	−42 B (−0.6%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.9 KiB	57.8 KiB	−44 B (−0.1%)	66.4 KiB	✅
Claude	Live turn messages	10	9	−1 (−10.0%)	21	✅

Baseline: e628683 · PR result: 13c1d2f · 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: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

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

Dismissing prior approval to re-evaluate 47e8390

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• packages/shared/src/usageMerge.ts

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📝 Walkthrough

Walkthrough

Usage scans now report incomplete coverage and preserve cached data after failed walks. Usage buckets retain source-directory attribution. Merge logic rejects ambiguous summaries and selects complete source coverage. Web and mobile status checks use full-summary mergeability.

Changes

Usage integrity

Layer / File(s)	Summary
Usage contract and merge attribution packages/contracts/src/usage.ts, packages/shared/src/usageMerge.ts, packages/shared/src/usageMerge.test.ts	The usage contract moves to v6 with optional bucket source indexes. Merge logic validates attribution, excludes failed sources, and marks ambiguous summaries as stale.
Source-scoped aggregation apps/server/src/usage/usageAggregation.ts, apps/server/src/usage/usageAggregation.test.ts, apps/server/src/usage/UsageService.ts, apps/server/src/usage/UsageService.test.ts	Deduplication and bucket creation include the source index. Failed transcript records are skipped, and source indexes are passed into aggregation.
Transcript scan coverage apps/server/src/usage/usageTranscriptReader.ts, apps/server/src/usage/usageTranscriptReader.test.ts, apps/server/src/usage/UsageService.ts, apps/server/src/usage/UsageService.test.ts	Transcript listings report ok, partial, missing, or failed status. Read failures return null, incomplete scans avoid cache pruning, and tests cover filesystem failures and recovery.
Environment status validation apps/web/src/components/usage/UsagePage.tsx, apps/mobile/src/features/usage/UsageRouteScreen.tsx	Environment status checks use isMergeableUsageSummary with the complete usage summary.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~45 minutes

Change: Bug fix · Severity of issue fixed: Medium

Sequence Diagram(s)

sequenceDiagram
  participant UsageService
  participant TranscriptReader
  participant UsageAggregator
  participant UsageMerge
  UsageService->>TranscriptReader: list files and coverage status
  TranscriptReader-->>UsageService: files and scan failures
  UsageService->>UsageAggregator: add readable records with source index
  UsageAggregator-->>UsageService: source-indexed buckets
  UsageService->>UsageMerge: provide usage summary
  UsageMerge-->>UsageService: mergeable or stale result

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Suggested reviewers: maria-rcks

Merge Risk: ⚪ Minimal · up to 13c1d

Usage scans now distinguish failed and partial coverage without assigning failed-directory records to healthy sources. No actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 53.85% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 13 functions across 11 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Issue #5798 requires readable usage retention, failed for unreadable roots, partial for nested or transcript read failures, bounded diagnostics, and distinct missing status. `listTranscriptFiles…
Out of Scope Changes check	✅ Passed	The aggregation, source attribution, contract v6, merge compatibility, web, mobile, and test changes support the scan-coverage fix. They prevent incomplete or duplicate sources from corrupting usage r…
Title check	✅ Passed	The title clearly summarizes the primary change: reporting incomplete transcript scans in usage processing.
Description check	✅ Passed	The description clearly explains what changed, why it changed, validation performed, known verification gaps, and review requirements. It does not reproduce the checklist or use the template headings,…

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Actionable comments posted: 2

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Inline comments:
In `@apps/server/src/usage/usageTranscriptReader.ts`:
- Around line 120-122: Update the nested directory traversal error handling
around isMissingEntry so only root-level ENOENT produces the missing status;
count nested readdir failures, including ENOENT, as failedEntries so the walk
reports partial coverage and cannot be treated as fully walked for cache
pruning.

In `@packages/shared/src/usageMerge.ts`:
- Around line 133-150: Align claimSources ownership with ownedContribution
bucket attribution so multiple fingerprints from the same provider cannot both
receive all provider buckets. Update the aggregation around claimSources,
ownedContribution, and UsageBucket to preserve fingerprint ownership through
bucket attribution, or consistently assign ownership at provider granularity;
add a regression test covering two same-provider fingerprints with reversed
ok/partial statuses.

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Reviewing files that changed from the base of the PR and between 20363c3 and 47e8390.

📒 Files selected for processing (6)

• apps/server/src/usage/UsageService.test.ts
• apps/server/src/usage/UsageService.ts
• apps/server/src/usage/usageTranscriptReader.test.ts
• apps/server/src/usage/usageTranscriptReader.ts
• packages/shared/src/usageMerge.test.ts
• packages/shared/src/usageMerge.ts

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[juliusmarminge]

Note

This comment is posted by Julius' dot

Closing under the prior-approval rule. This changes source ownership across environments, adds per-source bucket attribution, and excludes ambiguous v4/v5 summaries. #5798 describes the scan failure but has no maintainer triage confirming this merging and compatibility scope. Please get that intended behavior confirmed there and link the decision for reconsideration.