Vancetope — Session Modify / Crop

“Crop” removes messages from a Session’s memory without deleting them. The user can remove individual turns in the middle or “crop from here” (this message and all subsequent ones) — and restore everything at any time. Removed messages remain in the database (auditable) but are invisible to the AI: out of every LLM replay, compaction, recompaction, and history search path, and out of the chat history. The action is located in the Session menu of the chat list (✂) and opens a modal — the target Session does not need to be open.

See also: session-lifecycle session-duplicate memory-compaction websocket-protokoll

1. Marking — No New Attribute

“Removed” is expressed via the existing meta.kind type on ChatMessageDocument (the same mechanism as kind=interim), with the new value meta.kind = "removed":

  • ChatMessageDocument.KIND_REMOVED = "removed" + helper isRemoved() — parallel to KIND_INTERIM/isInterim().
  • No new DB field. Since ChatMessageDto.meta already goes to the client, the Crop UI sees the state (meta.kind === 'removed') without DTO changes.
  • Only the marker changes — content, role, tags, timestamps remain untouched. Reversible: removing the marker = message back in memory.

Distinction from other exclusion mechanisms: archivedInMemoryId (Compaction) folds messages into a Summary; STRENGTH:* tags are a soft filter. “Removed” is the explicit user decision “this does not belong in memory”.

2. Where “removed” is respected

Path Method Behavior
LLM Replay (all Engines, Compaction, Prak) ChatMessageService.activeHistory removed out (in addition to interim)
Chat Scrollback (REST) activeHistoryWithInterim removed out, interim remains (dimmed)
Crop Editor historyForCrop removed in (for restoration), interim out
Recompaction Range findActiveInRange removed out (Query Criteria)
history_search Tool search removed out (Query Criteria)
WS Resume Push SessionCreateHandler.pushAppendedMessages removed not re-emitted
Audit / Full History history removed in (nothing is lost)

3. Mutation

ChatMessageService:

  • markRemoved(tenantId, sessionId, ids) — $set meta.kind=removed, tenant+session-scoped, idempotent.
  • unmarkRemoved(tenantId, sessionId, ids) — $unset meta.kind, only on rows that are currently removed (protects a potential interim marker).

4. API

  • GET /brain/{tenant}/sessions/{id}/messages?includeRemoved=true — Crop list (logical conversation including removed, without interim). Owner-only (the normal scrollback remains readable for shared Sessions; the Crop view does not).
  • PATCH /brain/{tenant}/sessions/{id}/messages/crop — Body SessionCropRequest { remove: string[], restore: string[] } (both optional/idempotent). Owner-only, Action.WRITE. Response: the fresh Crop list (ChatMessageDto[]), so the modal re-renders in one roundtrip. Crop-from-point is expressed by the client as a remove list of all messages from the selected point.

5. Web UI

✂ Crop in the SessionActionsMenu (owner-gated, in any Session state — history survives archiving). If the Session is currently connected (session.bound — someone might be working on it), the UI warns in advance via a confirmation dialog before opening the modal (consistent with the Compact action, see session-compact §4). Opens SessionCropModal (Host: PickerView): list of all messages with a checkbox per turn, ✂ button “crop from here”, live preview (removed = struck through/red, restored = green), batch apply with change counter. Persisted only on “Apply” (Diff → remove/restore), before that purely local and discardable.

6. Limitations (v1)

  • No WS live notification to a currently open chat view of the same Session: anyone with the chat open in parallel will only see the removal after reload/reconnect. (The REST and Resume paths are consistent; only the ongoing live stream is not retroactively cleaned up.)
  • Cropping affects the chat process of the Session (the user conversation). Worker sub-processes do not have their own Crop interface.
  • No cascade to already generated Compaction Summaries: a Summary that summarized a message later removed will not be recomputed. New Compactions will consider the removed status.