dsh-force-compact

Aggressive, local-first context compaction for DeepSeek Harness agents.

A DSH Cordis function plugin that keeps the agent's working context lean by design: serve Qwen3.8‑27B on a self-hosted llama.cpp with a modest context, and the plugin shrinks the conversation itself — a large-window feel with no API cost and no data egress.

中文

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Why

• Self-hosted inference — the agent talks to a local OpenAI-compatible llama.cpp server through the standard DeepSeek adapter; no separate adapter needed.
• Low context, high signal — instead of fighting a small cap, the plugin shrinks the conversation, so the agent reasons over a tight prompt while keeping deep memory in the compressed head.
• Think off for compactions, passthrough everywhere else — disableThinking: true (default) turns thinking off on this plugin's own compaction summarization call only; every other model request rides the machine's configuration unchanged.
• Private & free — no per-token billing, no egress.

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What it does

Two compaction engines coexist behind one facade (resolveCompaction), transparent to callers:

Engine	Used when	Notes
Official	the compaction service resolves in the agent realm	Preferred; delegates to compaction/basic.
Builtin	automatic fallback (typical standard preset isolates the service)	Self-contained persistent transaction on ctx.sessions / ctx.llm.stream / ctx.tokenMeter; reuses the official compaction/* event vocabulary, so it replays safely across builds.

No toggling — official wins when reachable, builtin takes over otherwise.

Trigger points

• Per-request guard (agent/pre-step) — reads the session's projected context tokens (the exact number the harness renders bottom-right). At autoThresholdTokens it rejects the outgoing request and compacts the head instead, retaining the latest retainLatestTokens verbatim. Below the threshold the request proceeds.
• Turn end / idle (agent/status → idle) — when the agent quiesces, optionally compacts via compactNow (gate: turnEndForceCompactionEnabled).
• Manual /force-compact — immediate compactNow when idle; when busy it queues a process-local flag consumed at the next model step. Loaded lazily — see "Command availability" under Install.
• session/flush — the awaited durability checkpoint.

Every path funnels into the single "compaction result landed in the session" boundary — the same point where the LiveUI signal fires.

Decision key is projectedTokens (provider-anchored, same figure as the UI corner), so the plugin never drifts from what you see; the threshold-aware shrink gate skips summarizer calls that provably cannot pull the session below the threshold (kills the low-threshold dead loop).

The builtin transaction bills shadowedTokenCount from the same tokenMeter.measure per-node prices the official engine uses, so the meter's collapse protocol settles the drop correctly — the bottom-right counter goes down after compaction.

Thinking control: scoped to compactions

Since the 2026-08 semantics revision, disableThinking controls one thing: whether this plugin's own summarization call (engine/builtin.js → engine/summarizer.js → ctx.llm.stream) carries reasoningEffort:'off'. Everything else is untouched:

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