dsh-context-compression-improved

An improved fork of dsh-context-compression-selector — an auditable tool-result context-compression selector for DeepSeek Harness — adding an orthogonal code-skeleton compression gate.

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[!NOTE] What this fork adds on top of upstream 0.1.0:

• An orthogonal code-skeleton compression gate (codeSkeleton.enabled, default off): the first exposure of an oversized fresh source-code tool result can keep a skeleton of imports and declarations — bodies elided, error lines kept — before the regular reducers run.
• A settings toggle for that gate in the same selector settings section, independent of every compression profile.
• An ESLint baseline wired into CI, a test:watch TDD loop, and documentation in English, Simplified Chinese, Japanese, and Korean.

[!IMPORTANT] This project supports DeepSeek models only. Lossless measurement and lossy compression depend on the bundled official DeepSeek tokenizers (deepseek-v4-flash, deepseek-v4-pro, deepseek-v4-flash-vision-exp). Everything else fails open and keeps original tool results. See the upstream README for the full safety model.

What it is

Long-running agent tasks accumulate a large amount of tool output. This community plugin adds selectable, auditable policies for reducing that tool-result context without modifying DeepSeek Harness core:

• Fresh pre-compresses a newly oversized tool-result segment before the model receives it.
• Aggregate pre-compresses fresh material again when it still grows beyond its budget.
• History / micro-compact replaces eligible old tool results while preserving recent working context.
• TailTrim is an optional Custom-only tail reduction path.
• Native preserves the Harness-style head/middle/tail trimming as one explicit profile.
• Code skeleton (new, orthogonal gate) — see below.

Every decision is recorded: stage, reducer, trigger, skip reason, and exact token counts where available.

Code skeleton gate (new)

When the gate is enabled, an oversized fresh source-code tool result (for example a large read_file) first tries a skeleton reduction: imports and type/function/class declarations are kept, function bodies are elided with a marker, and error lines inside elided bodies are preserved. If the skeleton cannot be produced or verified, the result falls back to the original head pruning — the gate can never make context worse.

Properties:

• Orthogonal: independent of the selected profile (balanced, savings, cache-strict, adaptive, custom, off, native). All profiles get the gate.
• Off by default: codeSkeleton: { enabled: false } until you turn it on.
• Measurement-gated: requires the exact DeepSeek tokenizer; without it the plugin fails open.
• Session-frozen: like all selector settings, changes affect newly observed sessions only.
• Strictly parsed: codeSkeleton must be exactly { enabled: boolean }; malformed values throw on the runtime side and show as unreadable in the browser UI.

Settings UI

Choose a compression profile, set the Auto Compact trigger level, and toggle code-skeleton compression in the same settings section. The toggle saves on change and shows the saved state on reload.

Install

Recommended: install from npm. One dist-tag per Harness line — dsh-0.2.0 for the 0.2.0 line (this branch), dsh-0.1.7 for the 0.1.7 line, dsh-0.1.5 for the 0.1.5 line, dsh-0.1.2 for the 0.1.2 line.

dsh plugin --profile web add dsh-context-compression-improved@dsh-0.2.0
# DSH 0.1.7 line:
# dsh plugin --profile web add dsh-context-compression-improved@dsh-0.1.7
# DSH 0.1.5 line:
# dsh plugin --profile web add dsh-context-compression-improved@dsh-0.1.5
# DSH 0.1.2 line:
# dsh plugin --profile web add dsh-context-compression-improved@dsh-0.1.2
dsh --profile web --dump-config

From source (alternative — the internal package names intentionally stay upstream's):

git clone https://github.com/drscrewdriver/dsh-context-compression-improved.git
cd dsh-context-compression-improved
pnpm install --frozen-lockfile
pnpm build

Then pack the selector package and add it to a Harness profile — the full walkthrough, including verification and uninstall steps, is in the installation guide.

Development

pnpm install --frozen-lockfile
pnpm lint          # ESLint baseline (also enforced in CI)
pnpm typecheck     # runtime + selector + tests tsc, plus the bundle step
pnpm test          # full vitest suite
pnpm test:watch    # TDD loop: write the failing regression first, then make it pass
pnpm build
pnpm verify:release

Contributions follow the upstream discipline: add the failing regression first, keep every production change inside this repository, and explain “triggered”, “enabled but skipped”, and fail-open evidence separately. See CONTRIBUTING.md.

Compatibility

• Built and tested against the official DeepSeek Harness dsh-v0.2.0-rc.1 release; peers declare >=0.2.0-rc.1 <0.2.1-0 and the plugin uses public plugin and profile APIs only. Earlier lines remain served from their own dist-tags (dsh-0.1.7, dsh-0.1.5, dsh-0.1.2).
• Requires Node ^22.19.0 || >=24 and pnpm 11.7.0.
• The plugin uses only public Harness extension APIs and does not modify Harness core code. Unofficial community project, not affiliated with or endorsed by DeepSeek.

Credits and license

• Upstream project and all prior work: WilliamShi666/dsh-context-compression-selector by WilliamShi666 (MIT).
• Fork additions (code-skeleton gate, tooling, localized docs): drscrewdriver.
• MIT — see LICENSE (upstream copyright notice retained) and THIRD_PARTY_NOTICES.md for bundled tokenizer provenance.