Opening a thread loaded 0.3 to 3 MB, even when the thread itself was only 16 to 75 KB. Mobile felt it most.
The real cost was provider config. Each provider keeps per-folder "workspace snapshots" (slash commands and skills, 8 to 27 KB each, up to 16 per provider). Every thread open asked the server to scan the thread's folder. The reply held every provider with every snapshot, and the server also pushed that same list to every connected client. A deleted worktree never finished scanning, so its composer retried every 10 seconds, forever.
Images above the visible area also loaded at full size, because the timeline mounts nearby rows.
workspaceSnapshotsOnDemand. The config stream then leaves snapshots out, so a rescan sends nothing. A folder refresh returns only that provider's snapshot for that folder. The client keeps what it fetched and merges it back into config, so web and mobile readers do not change.providerWorkspaceSnapshotsOnDemand. Against older servers they use the config as is./usage-limits, a sign-out. The composer then fetches the snapshot again at once.loading="lazy". Mobile's list already draws only rows near the screen.Real data copy (325 threads), dev server restarted and client caches cleared for each side, mobile viewport, same 7 thread opens. Bytes are WebSocket JSON plus HTTP, without dev-mode JS.
| Load | main | this PR | cut |
|---|---|---|---|
| App load (new thread) | 521 KB | 393 KB | 25% |
| Open thread 1 | 1423 KB | 203 KB | 86% |
| Open thread 2 | 277 KB | 94 KB | 66% |
| Open thread 3 | 708 KB | 40 KB | 94% |
| Open thread 4 | 802 KB | 88 KB | 89% |
| Open thread 5 | 808 KB | 48 KB | 94% |
| Open thread 6 | 943 KB | 137 KB | 85% |
| Open thread 7 (71 child threads) | 3046 KB | 293 KB | 90% |
| Total | 8528 KB | 1296 KB | 85% |
App load includes 228 KB of dev-only brand icons. Production icons are 114 KB and cached. Without them, app load goes from 298 KB to 170 KB. App load plus a typical thread open is now about 260 KB. JS bundle size is a separate track and is not counted here.
getThreadFamily sends about 2.5 KB per child thread (176 KB for 71 children). That is a follow-up.ws.test.ts: the stream drops snapshots, a snapshot-only rescan sends nothing, and a scoped refresh returns one folder.ProviderRegistry.test.ts: a second request waits for the running scan, still gets the result after the first request leaves, and only one scan runs.server.test.ts: the merge, its capability gate, identity reuse, and dropping a snapshot when provider-wide commands change.ClaudeCapabilitiesProbe.test.ts: a deleted folder is not pending.vp run check:changed passes./ menu still lists repo-scoped skills from the folder snapshot, and /usage-limits.Surfaces: web and desktop share the client-runtime path. Mobile uses the same path and gets the same retry cap.
Builds on main, not #24692. The council measured the thread payload at 1 to 8% of a thread open, so lazy folded rows were not worth the extra protocol.
Rounds: 4. A round 0 before any code also chose the cuts.
| Delegate | Round 1 | Round 2 | Round 3 | Round 4 |
|---|---|---|---|---|
| Claude Opus 5.5 | 7/10 | 8.5/10 | 9/10 | 9.5/10 |
| Muse Wonder Full | 8/10 | 9/10 | 9.5/10 | 9.5/10 |
| Codex GPT-6.1 Sol | 7/10 | 8/10 | 9/10 | 9/10 |
Created with Claude Opus 5.5 in Claude Code.
🤖 Generated with Claude Code
Added 1 commit
Verdict: Needs Human Approval
Macroscope's review found this PR requires human approval — This PR introduces a cross-cutting on-demand workspace-snapshot protocol, client-side cache/merge logic, and changed ProviderRegistry scan lifecycle behavior. It also enables the new transport mode by default, so the resulting production behavior and default configuration path merit human review.
You can add or adjust custom eligibility rules. Learn more.
✅ 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 | 1 | 1 | 0 (0.0%) | 8 | ✅ |
Baseline: 5b35402 · PR result: 67b8ab3 · Source CI: success
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.
Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.
No actionable comments were generated in the recent review.
504f8721-6601-42fc-ad83-9be1bd0be396Reviewing files that changed from the base of the PR and between 5b35402623d7d1d88eaa472807272a6c2e78012a and 67b8ab3b6b6b18016d2e543b889188c075909df4.
apps/mobile/src/features/threads/use-composer-command-menu.tsapps/server/src/environment/ServerEnvironment.tsapps/server/src/provider/ClaudeCapabilitiesProbe.test.tsapps/server/src/provider/ClaudeProvider.tsapps/server/src/provider/ProviderRegistry.test.tsapps/server/src/provider/ProviderRegistry.tsapps/server/src/ws.test.tsapps/server/src/ws.tsapps/web/src/components/chat/ChatMarkdownMedia.tsxapps/web/src/components/chat/TimelineUserMessageRow.tsxapps/web/src/components/chat/useProviderWorkspaceSnapshotRefresh.tspackages/client-runtime/src/rpc/session.tspackages/client-runtime/src/state/server.test.tspackages/client-runtime/src/state/server.tspackages/contracts/src/environment.tspackages/contracts/src/rpc.tsIncluded review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 9 remain after this review.
The change adds on-demand workspace snapshot delivery, client-side snapshot caching, and limits on failed refresh retries. It also updates workspace scan coordination and Claude probing, and enables lazy loading for chat images.
Changes: On-demand workspace snapshots
| Layer / File(s) | Summary |
|---|---|
Snapshot contract and scan handling packages/contracts/src/environment.ts, packages/contracts/src/rpc.ts, apps/server/src/environment/ServerEnvironment.ts, apps/server/src/provider/ProviderRegistry.ts, apps/server/src/provider/ProviderRegistry.test.ts, apps/server/src/provider/ClaudeProvider.ts, apps/server/src/provider/ClaudeCapabilitiesProbe.test.ts | The environment and RPC contracts add on-demand snapshot options. Workspace scan refreshes coordinate through deferreds, and a test covers a waiting refresh after interruption. Claude probing skips a nonexistent working directory, with a test for slashCommandsPending. |
Server snapshot delivery apps/server/src/ws.ts, apps/server/src/ws.test.ts | Config subscriptions can omit workspace snapshots. On-demand refreshes return only the requested instance and working-directory snapshot; provider-status updates omit snapshots when requested. WebSocket tests cover these responses and updates. |
Client snapshot fetching and cache packages/client-runtime/src/rpc/session.ts, packages/client-runtime/src/state/server.ts, packages/client-runtime/src/state/server.test.ts, apps/mobile/src/features/threads/use-composer-command-menu.ts, apps/web/src/components/chat/useProviderWorkspaceSnapshotRefresh.ts | Client subscriptions request on-demand snapshots. The client records and merges fetched snapshots when the saved provider basis matches, and tests cover cache behavior. Mobile and web refresh hooks stop retrying after three failures for a key. |
Chat image loading
| Layer / File(s) | Summary |
|---|---|
Lazy loading for chat images apps/web/src/components/chat/ChatMarkdownMedia.tsx, apps/web/src/components/chat/TimelineUserMessageRow.tsx | Markdown images and attachment previews set image loading to lazy. |
Priority: External image Normal
Estimated code review effort: 4 (Complex) | ~45 minutes
Change: Feature
| 1 | sequenceDiagram |
| 2 | participant ClientRuntime |
| 3 | participant WebSocketServer |
| 4 | participant ProviderRegistry |
| 5 | participant ClientSnapshotState |
| 6 | ClientRuntime->>WebSocketServer: Subscribe with workspaceSnapshotsOnDemand |
| 7 | WebSocketServer-->>ClientRuntime: Config without workspace snapshots |
| 8 | ClientRuntime->>WebSocketServer: Refresh requested instance and cwd |
| 9 | WebSocketServer->>ProviderRegistry: Refresh workspace snapshot |
| 10 | ProviderRegistry-->>WebSocketServer: Workspace snapshot |
| 11 | WebSocketServer-->>ClientRuntime: Return requested snapshot |
| 12 | ClientRuntime->>ClientSnapshotState: Record and merge snapshot |
Possibly related issues
Suggested reviewers: juliusmarminge, exotic209093, justyannicc
67b8aThe supplied evidence does not establish a merge-blocking problem. Complete normal checks before merging.
| Check name | Status | Explanation |
|---|---|---|
| Title check | Passed | The title clearly states the primary performance improvement: opening a thread transfers substantially less data. It is concise and relevant to the changes. |
| Description check | Passed | The description is detailed and covers the problem, implementation, compatibility behavior, limitations, verification, test coverage, and measured results. The scope and approval section does not expl… |
| 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. |
Explanation
The description is detailed and covers the problem, implementation, compatibility behavior, limitations, verification, test coverage, and measured results. The scope and approval section does not explicitly link a triaged issue or maintainer approval, but the overall description is complete enough to pass.
Comment @coderabbitai help to get the list of available commands.