dsh-history-fold

Configuration

$DSH_HOME/dsh-history-fold/config.json (falling back to ~/.dsh/…). It is re-read on every turn, so edits apply without a restart.

Key	Default	Meaning
enabled	false	Master switch. false ⇒ loaded but completely idle.
dryRun	true	true ⇒ observe and log only, never write.
profile	true	Write one size/profile line per turn.
triggerSurfaceTokens	250000	Fold only above this much visible history.
targetSurfaceTokens	180000	Fold down to about this much. Must be reachable — see below.
keepRecentNodes	60	Never fold the most recent this-many nodes.
minFoldNodes	20	Refuse to fold fewer nodes than this.
minFoldTokens	20000	Refuse to fold fewer tokens than this.
archive	true	Write the lossless pre-fold archive. Leave this on.
archiveDir	history-fold/archive	Relative to $DSH_HOME.
digestMaxChars	30000	Cap on the in-context index. Over budget ⇒ sample, never truncate.
digestLineChars	160	Characters of each sampled message shown in the index.
onlyAtTurnStart	true	Fold only before a turn's first step, never mid-turn.
logFile	logs/history-fold.jsonl	Relative to $DSH_HOME.
memoryFeed	false	Post the same digest to a memory service after each fold.
memoryFeedUrl	—	e.g. http://127.0.0.1:7999/memory-eternal/api.

targetSurfaceTokens must be reachable. At least keepRecentNodes nodes always stay, which is at least that many steps' worth of tokens. A target below that floor can never be met and the plugin will log no-safe-cut every turn.

Relation to the built-in compactor, and to the other "fold"-named plugins

	built-in dsh-compaction-basic	this plugin	UI-fold plugins
What replaces the history	a model-written summary	an extractive index + an archive pointer	nothing — the request is untouched
Cost per fold	one extra model call	none, no model call at all	none
Is the original kept	no — the summary is all that survives	yes, verbatim, in $DSH_HOME/history-fold/archive/	n/a
Recoverable	no	yes, with one rg over the archive	n/a
What it changes	the surface (what the model is sent)	the surface (what the model is sent)	the display (long messages collapsed in the UI)
Trigger	thresholdRatio × contextWindow, 800k by default	triggerSurfaceTokens; keep it below the compactor's line	n/a

Keep the trigger below the compactor's line. dsh-compaction-basic fires at thresholdRatio × contextWindow — 0.8 × 1,000,000, so 800k — and keeps 0.16 × window (160k). Its replacement is a model-written summary, which is lossy. Folding first is what stops that summarizer from ever firing at all.

A plugin with fold in its name is often a display fold: it collapses a long message in the UI so it is easier to read, and leaves the request payload exactly as it was. This plugin is the opposite — it does not touch the UI at all, and every byte it moves is aimed at the tokens sent on the next request. Decide which of the two you actually want before installing.

For the on-disk side of the same problem — session logs growing because finalised streaming fragments are never removed — see dsh-session-vacuum.