billion-context-dsh: A DSH plugin where the model decides when to compact context

What Does It Do?

Billion-Context is a DSH plugin for DeepSeek Harness that hands the decision of when and what to compress to the model itself. It solves the problem of long conversations being hard-truncated and early messages silently dropped: the model calls a compress tool to write high-fidelity summaries that keep file paths, decisions and error messages while reclaiming context space. Compressed ranges become recoverable checkpoint nodes, with the original text kept in an append-only session log, so very long tasks are far more likely to finish.

Core Features

• Model-driven compaction: summaries are written by the model itself, with no second LLM summarization call, so timing and scope stay under model control.
• Advisory, not mandatory: the automatic policy only nudges, leaving whether and when to compress to the model.
• Persistent and recoverable: compressed ranges become checkpoint nodes, decompress restores the original text, and search_context finds details inside a block.
• Four model tools: compress, decompress, search_context and acp_status cover compaction, recovery, retrieval and status self-verification.
• Lean context throughout: each request uses only a small, refined context instead of one large uniform compaction, so detail does not decay and token usage drops.
• Global mounting: it acts as the DSH compaction backend across all modes (standard, code, minimal, cordis and custom presets), with automatic window detection and tools, command and nudge enabled by default.

How to Use This Plugin?

After enabling it in DSH, open a new session and let the model call acp_status or run /acp-prune status to confirm the mount. During normal conversation the model decides when to call compress on a range of context; use decompress to bring the original text back and search_context to look up details inside a compressed block. To adjust behavior, override the default config with a compaction-acp line of the same id in your profile patch, for example by setting modelContextLimit; when omitted, the real model window is detected automatically. Maintained by Tyan66666 under the MIT license, the plugin reuses the acp-kernel compaction core with an adapter layer rewritten for the DSH durable-surface model, and it remains a beta release not intended for production use.

How to Troubleshoot This Plugin?

Two backends registering ctx.compaction in the same realm will conflict, so mounting ACP requires disabling the host compaction-basic at the same time; bundle installs already include that fallback. If it fails to work on an older DSH, the session replace operation protocol fields were renamed with stricter validation and this engine only emits the new shape, so upgrade DSH before installing this release. When installing from a git source and build scripts are blocked, use the committed prebuilt artifacts instead, which need no build step.