dsh-cas-results

DeepSeek Harness plugin that keeps bulky tool output out of the model context without throwing it away: large tool results are stored once in a local content-addressed store keyed by SHA-256, the session keeps only a bounded deterministic preview plus a stable reference, and the agent can retrieve or search the original on demand.

[dsh-cas-results: 2871934B html → 4096B preview; sha256=ac7819…e029; use dsh_cas_retrieve]
type: text/html

HTML document
title: Example
…

Full content:
dsh_cas_retrieve(ref="sha256:ac7819…e029")

Features

• Ingestion-time offloading — successful tool results are inspected before they enter model history; oversized string fields are replaced with bounded previews while the canonical value stays intact.
• Content-addressed storage — payloads are stored by SHA-256 over the logical bytes; identical content is stored once across tools, turns, and sessions (gzip storage codec is optional and never affects identity).
• Recursive JSON scanning — stdout, html, base64 blobs: every string field over its threshold becomes an independent CAS object; the value's shape is preserved.
• Base64/binary awareness — data URIs and confident raw base64 payloads are decoded, deduplicated as binary, and re-encoded on retrieval. Detection is deliberately conservative (SPEC §11).
• Deterministic previews — head/tail for text, keep-patterns for logs, title plus text-only body for HTML, and a payload-free marker for binary. No LLM, no clocks, no locale-dependent output.
• Retrieval tools — dsh_cas_retrieve (bounded, paginated, utf8/base64/ hex), dsh_cas_search (substring with context lines), dsh_cas_info, dsh_cas_stats, and an opt-in dsh_cas_gc.
• Fail-open safety — storage failures, corrupt blobs, and disabled config always leave the original tool result untouched; tool errors are never transformed by default.
• Bounded storage — TTL plus quota garbage collection with oldest-access eviction and orphan staging cleanup.
• Zero core changes — the plugin rides the public tools/post-execute seam and the public tool registry; DSH stays untouched.

Install

Install the published npm package by name:

dsh plugin --profile <profile> add @yadsh/dsh-cas-results

From a checkout of this monorepo, build the package and link the checkout:

pnpm nx run @yadsh/dsh-cas-results:build
dsh plugin --profile <profile> add ./plugins/dsh-cas-results

Configuration

Configuration lives in the plugin's composition entry (cordis.patch.yml override layers or profile patches). All fields are optional.

Option	Type	Default	Description
enabled	boolean	true	Master switch; false passes every result through.
storeDir	string	""	Store root; empty resolves to <$DSH_HOME>/storages/dsh-cas-results.
thresholds.textBytes	number	16384	Offload threshold for generic text in bytes.
thresholds.htmlBytes	number	8192	Offload threshold for HTML in bytes.
thresholds.logBytes	number	16384	Offload threshold for log-like output in bytes.
preview.maxChars	number	4096	Character budget for preview bodies.
preview.keepHeadLines	number	20	Head lines kept in text/log previews.
preview.keepTailLines	number	30	Tail lines kept in text/log previews.
preview.keepPatterns	string[]	error, warn, …	Case-insensitive substrings kept from the middle of logs.
base64.enabled	boolean	true	Decode and deduplicate base64/binary payloads.
base64.minChars	number	8192	Minimum candidate length before detection runs.
base64.requireStrongDetection	boolean	true	Require data-URI context or binary evidence for raw candidates.
storage.compression	"none" | "gzip" | "auto"	"auto"	On-disk codec; identity is always computed over logical bytes.
storage.maxBytes	number	10737418240	Logical-byte quota enforced by GC.
retrieval.defaultBytes	number	32768	Default chunk size for dsh_cas_retrieve.
retrieval.maxBytes	number	262144	Hard upper bound for one retrieval chunk.
gc.enabled	boolean	true	Run background garbage collection.
gc.intervalMs	number	3600000	GC interval in milliseconds.
gc.ttlMs	number	2592000000	Objects untouched for this long become eligible.
gc.minAgeMs	number	86400000	Routine GC never deletes objects younger than this.
includeErrors	boolean	false	Also preview oversized text inside failed results.
excludeTools	string[]	["write", "edit", "str_replace_editor"]	Tools whose results are never transformed.
tools.<name>.thresholdBytes	number	—	Per-tool offload threshold override.
tools.<name>.preview	"auto" | "text" | "log" | "html"	"auto"	Forced preview style for the tool.
tools.<name>.base64	boolean	—	Per-tool base64 on/off override.
tools.<name>.disabled	boolean	—	Skip transformation for this tool entirely.
exposeGcTool	boolean	false	Register the model-facing dsh_cas_gc tool.

Compatibility

• DeepSeek Harness >=0.1.7-rc.2 <0.2.0 (host-service plugin; no client UI).
• Node.js ^22.19.0 || >=24.0.0.
• See compatibility.json for the machine-readable contract.

Development

pnpm nx run dsh-cas-results:lint
pnpm nx run dsh-cas-results:typecheck
pnpm nx run dsh-cas-results:test
pnpm nx run dsh-cas-results:build
pnpm nx run dsh-cas-results:verify

The plugin contract and its verifiable guarantees live in SPEC.md.

Credits

dsh-cas-results is inspired by dsh-funnel by YuanyuanMa03.

dsh-funnel pioneered the ingestion-time tool-result curation approach used as the conceptual and implementation starting point for this plugin. See NOTICE.md for attribution details.

License

MIT