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<Message, seq> 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:<this dir> 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.
