dsh-vcc

Deterministic, no-LLM conversation compaction for DeepSeek Harness, with lossless recall — adapted from pi-vcc's view-oriented compiler approach.

When a session grows past its window, instead of paying an LLM to compress the history, dsh-vcc compiles the conversation into a structured, stable summary:

[Session Goal] / [Files And Changes] / [Commits] / [Outstanding Context] / [User Preferences] header sections, merged across compactions (dedup, cross-compaction file merge, volatile sections rebuilt fresh);
a ranked brief transcript (--- separated) whose messages keep lossless (#N) references into the session log.

(#N) is the event seq — the same index vcc_recall searches — so anything compaction drops stays one deterministic call away:

vcc_recall(query: "redis cache decision")     → ranked, paged hits (#N)
vcc_recall(expand: [42])                       → full untruncated content
vcc_recall(query: "#42:auth.ts")               → drill into a file from an entry
vcc_recall(query: "#42:auth.ts:full")          → all lines of that file content
vcc_recall(mode: "touched")                    → files worked on, with entry indices
vcc_recall(scope: "all")                       → also reach edited/retried branches

Also ships /vcc (preview the summary the next compaction would write, with no mutation) and /vcc-recall (the tool as a human command).

Layout

Path	Role
`index.js`	`DshVccCompactionEngine` (default export) — extends the basic backend, overrides its `summarize` hook with the deterministic pipeline; registers the recall tool and commands.
`lib/dsh-adapter.js`	DSH message → pi message shape (tool-call id→name correlation, reasoning policy).
`lib/session-source.js`	Session events → message streams (`lineage` = live surface, `all` = full log).
`lib/engine-util.js`	seq alignment for `(#N)` refs; previous-summary extraction.
`lib/drill-down-dsh.js`	`#N:path` drill-down, re-rooted on session events.
`lib/recall-tool.js`	`vcc_recall` tool + shared recall algorithm.
`lib/commands.js`	`/vcc` and `/vcc-recall` human commands.
`src/`	The pi-vcc core pipeline compiled to ESM (MIT, see NOTICE): normalize, filter-noise, sections, rank, build-sections, summarize, search-entries, render-entries, format-recall, recall-scope, extract/*.
`cordis.patch.yml`	Enables the engine inside the preset's `compaction` group and disables the preset's stock LLM backend.
`node_modules/@deepseek-ai/*`	Symlink farm to the harness checkout packages the bundle imports at module-eval time (see below).

How it works

The bundle mounts one service row (dsh-vcc) into the cordis agent preset's compaction group and disables the preset's stock compaction-basic row in the same group. Preset sessions then resolve ctx.compaction to DshVccCompactionEngine — a subclass of the basic backend that keeps all of its machinery (threshold/overflow auto triggers, region selection, (maxTokens) shrink gate, retry backoff, durable session mutation, compaction/summary events) and replaces only the summarize hook with compileRanked from the ported pi-vcc core.
Alignment: buildSummarizationInput hands the engine the exact messages it plans to shadow; messages are the durable surface objects, so an identity map (Map built from session.surface.nodes) recovers each message's event seq, fail-closed. The summary's (#N) refs and vcc_recall's indices are the same seqs — self-consistent by construction.
The compiled result is returned as { summary, rawOutput, provider: 'dsh-vcc', model: 'deterministic' } with no llmStreamCall — the non-LLM branch of the backend's SummaryResult. An empty compile throws, so the backend treats it like a summarizer that produced nothing (retry/error path).

Install & verify

plugin_manager  →  install_bundle  →  target: /home/user1/dsh-compaction/dsh-vcc

install_bundle records @local/dsh-vcc: link: in the profile's package.json and applies cordis.patch.yml; no restart is needed on first install.
Confirm: cordis_inspect_query (Host Config / Tool / Service), then run /vcc in a cordis-preset session to see the live deterministic preview, and /compact to compact. vcc_recall then answers questions about the shadowed history.
Replacing an already-installed version of the same package still needs a profile restart to load the new module generation.

Known scope (v1)

Activates for the cordis preset only (the patch targets the last-occurring rows in the composed profile). standard / ptc / minimal presets keep their stock compaction backend.
Deterministic by design: no LLM calls, no network, no nondeterminism — identical input always produces identical output.
Only the current session is searchable; earlier sessions are not.

Attribution

dsh-vcc is a port of pi-vcc (MIT) — itself derived from pi-blackhole (by k0valik, MIT) and invisible-continue (by monotykamary, MIT). The compiled core under src/ is the pi-vcc pipeline (normalize, filter-noise, build-sections, rank, summarize, extract/*, search/render/format-recall, recall-scope) with only its load-messages/JSONL layer replaced by lib/session-source.js and its drill-down re-rooted on session events. See NOTICE for the full license texts.

Install

README