d04b05b5c8
* fix(memory): detach retained CI and terminal tails from oversized strings * fix(terminal): detach retained error and reattach string slices * fix(terminal): release oversized recent-output backing strings * fix(terminal): release backing strings held by PTY detectors * fix(memory): own bounded Claude background task labels * fix: detach retained terminal mode scan tails * fix: own retained plugin worker output strings * fix: own incomplete OSC 133 carry strings --------- Co-authored-by: m4air <m4air@Mac.localdomain> Co-authored-by: m4air <m4air@m4airs-MacBook-Air.local>
Retained Claude background-task text
The actual Claude task tracker retained oversized input strings through its
512-character description/name slices. Its live tasks, settled tasks, and
recently removed tasks can each retain those slices. The fix uses the existing
ownRetainedString at the shared text boundary; normalization, UTF-16 clipping,
task identity, publication, and lifecycle behavior stay the same.
This extends ML-018 / #20960.
Reproduce
ORCA_BACKGROUND_LAUNCH=1 node --expose-gc docs/audits/claude-task-retention/reproduce.cjs
The script bundles the actual tracker and its retention classes. Its baseline removes only the new copy call in memory. It exercises flat strings, concatenated strings, and JSON-parsed SDK-style frames; each input has a distinct task owner. It measures after GC, then clears the tracker and yields before measuring cleanup. Results and bundle hashes preserve the complete run.
| JSON-parsed case | Input per task | Tasks | Visible text | Heap before | Heap after |
|---|---|---|---|---|---|
| Live | 64 Ki characters | 32 | 16,384 characters | 2,125,672 | 43,536 |
| Settled | 64 Ki characters | 32 | 16,384 characters | 2,127,072 | 44,296 |
| Removed, awaiting outcome | 64 Ki characters | 32 | 0 characters | 2,108,136 | 25,360 |
| Live | 4 Mi characters | 8 | 4,096 characters | 33,562,624 | 11,048 |
| Settled | 4 Mi characters | 8 | 4,096 characters | 33,563,960 | 11,656 |
| Removed, awaiting outcome | 4 Mi characters | 8 | 0 characters | 33,558,584 | 7,008 |
Captured with Node v26.6.0 on macOS. Cleanup returned near the initial heap for every case. Six regression tests retain the actual tracker through these three lifetimes for both descriptions and names. Text behavior tests preserve whitespace normalization, fallback names, and a clipped surrogate pair.
Reachability and limits
claude-stream-json-connection.ts forwards SDK messages to the structured adapter,
whose emit calls backgroundTasks.observe. Installed SDK 0.3.251 uses Node
readline to assemble stdout records, parses each record with JSON.parse, then
yields it. The inspected path imposes no record or description length limit;
native read-chunk size does not cap an assembled JSON field. Descriptions are
declared as plain strings in SDKTaskStartedMessage.
The description slice and this SDK version also exist in v1.4.198; that tag
keeps the reader inline in claude-background-task-tracker.ts. The separate
settled/recently-removed retention and name-reader paths describe current code.
The current maps are count-bounded: at most 256 live, 256 settled, and 256 recently removed entries per tracker. Settled context clears when no visible work remains; recently removed context awaits an outcome, eviction, or explicit clearing. Session end/close clears the tracker. Copy work is at most 512 UTF-16 code units per retained field, and it does not reduce temporary parsing allocation.
These are synthetic oversized task fields, not evidence that an affected user received such fields. The path concerns structured Claude sessions, not ordinary terminal output or stderr. Neither #19831 nor #19768 establishes this trigger.
The separate digest-bounded subagent ID was also checked at actual consumers. The mobile response sanitizer can temporarily retain the original until JSON serialization flattens its concatenated ID. Worker transcript bounding already serializes for its byte budget and released that parent in the probe. No durable ID-owner leak was established, so that helper is unchanged.