Born for Code — The Code Engineering Specialized Version of DeepSeek Harness.

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Forged for Code: A Deeply Specialized Coding Agent

General agents handle broad daily tasks well, but stumble in complex software engineering — lacking understanding of project context, file trees, and build chains.

DeepSeek Harness Code is built to solve exactly that. As a dedicated specialization branch of DeepSeek Harness, it channels the model's reasoning strength into high-quality software code — from single-file edits to multi-module collaborative refactoring, with end-to-end engineering support. Broad agents suffer from generic tool scheduling and vague context management; code engineering is a rigorous deterministic art. We strip the baggage of generic scenarios and deeply bind reasoning to real software environments (AST parsing, terminal, code sandbox, Diff editing) — delivering straight to the engineering essence.

Why specialization?

• Precise engineering context — deep code indexing and file-dependency awareness, no more lost context.
• Native terminal & Diff — not plain text output, but canonical Patches with sandboxed test execution.
• Minimal integration cost — out of the box, directly embeddable into existing editors and CLI workflows.

Integration Philosophy

We don't chase boundless complexity. We adhere to a code-tailored engineering philosophy:

1. Scenario Specialized — Focus on the code lifecycle, cut every bloated design unrelated to programming.
2. Modular Decoupling — Scheduler and toolchain decoupled, freely pluggable with custom LSP, Linter, and sandbox.
3. Deterministic Delivery — Test- and verification-driven, replacing model hallucination with real execution results.
4. Controllable & Traceable — Full change logs and rollback, ensuring every modification is safe and transparent.

DHC remains a community project built on the public Harness format and the Code-DSH maintained runtime. No model weights are bundled and no provider boundary is replaced.

QQ community

Join the DHC community QQ group to share feedback, usage tips, and project discussions.

• QQ group: 1107534919

One complete DeepSeek Harness distribution

A complete, coherent Harness distribution — not a model launcher or plugin collection. The maintained Base and Web bundles bring the core of the DeepSeek Agent stack into one app:

• Models & reasoning — V4 Pro / V4 Flash catalog, reasoning effort off / high / max, 1M context, retry and streaming.
• Skills — runtime, file discovery, Skills UI, badges, and official Skill tool.
• Agent workflow — Standard presets, Goal / Plan / Todo / Jobs / Workflow, compaction, checkpoints, and persistent sessions.
• Tools — file read/search/edit, Bash / PowerShell, Web, user questions, approvals, subagents, feedback, and deliverables.
• Plugin platform — official plugin inventory plus integrated desktop and Anchored Standard bundles.
• Desktop reliability — native lifecycle, secure bridge, health recovery, rotating diagnostics, and independent Watchdog.

Everything is pinned, packaged, and validated as one product boundary.

Modernizing the BETA1 experience

BETA1 provides the foundation, but early Web experience leaves key problems to the user. DHC builds a modern application layer:

• Long-session memory — bound desktop growth paths, rotate diagnostics, prevent overlapping recovery, retire superseded processes.
• Web freezes — detect persistently unresponsive renderer, replace window without destroying healthy Harness.
• Fragile lifecycle — own startup, readiness, serialized restart, bounded shutdown, port retry, and session-aware recovery.
• Scattered capabilities — ship runtime, plugins, Skills, tools, workflows, questions, approvals, and extensions as one tested package.
• Desktop gaps — add native menus, tray, close preferences, system appearance, shortcuts, transitions, settings, and accessible diagnostics.

The goal is not to fork the protocol, but to make the experience more complete, modern, and reliable while preserving the official Harness model.

A more complete V4 Pro experience

V4 Pro is one important capability of this integrated foundation, not its sole center. The pinned adapter publishes deepseek-v4-pro / deepseek-v4-flash with off / high / max reasoning. The app bundles integration and runtime — not model weights; credentials stay in official Harness settings.

Tool-surface anchoring

The next step is not a keyword to "turn on reasoning," but controlling the first-request tool surface to preserve the high-quality trajectory V4 Pro is capable of.

• Standard: 25 tools visible upfront, easy to fall into inefficient Let me..., Project2 ~9,192.
• Minimal: only Shell + Read, more likely to recover We need..., Project2 ~9,699.

dsh-anchored-standard solves this with first-request anchoring + dynamic promotion: expose only bash + str_replace_editor first, unlock the full 25 tools after the first durable call. Consecutive 98 / 99 on native Windows Project2.

Beyond a Web wrapper

Capability	Basic Web wrapper	DeepSeek Harness Code
Runtime	Loads a remote page	Bundled Chromium + maintained Harness + plugins, system Node
Model integration	Inherits page models	First-class V4 Pro / Flash catalog and reasoning controls
Agent toolkit	None	Plugins, Skills, Goal / Plan / Workflow, questions, subagents
Process ownership	Page is the product	Desktop host owns Harness startup, readiness, restart, shutdown
Long-session health	Manual refresh	Non-overlapping health probes and evidence-based recovery
Web freeze	Reload entire app	Detect unresponsive renderer, rebuild window, keep Harness alive
Service failure	Noticed after UI stops	Auto-recover after consecutive probe failures or child exit
Desktop crash	No independent layer	IPC-only Watchdog with bounded backoff and circuit breaker
Memory pressure	Inherits unbounded	Bounds growth paths, rotates logs, retires failed processes
Diagnostics	Browser console only	Redacted Electron / Harness / Watchdog logs, in-app access
Desktop integration	Window chrome only	Native tray/menu, close policy, system theme, shortcuts
Security boundary	Broad preload access	Loopback-only Harness + five validated preload groups
Distribution	Requires external env	Self-contained app, auto-detected common install locations

Lightweight wrappers solve "open this site like an app"; DHC solves "operate Harness as a resilient desktop coding system."

Built for long-running work

Long sessions rarely crash dramatically — pressure accumulates: renderer stalls, child exits, checks overlap, logs grow unbounded, zombie processes linger.

• Health monitoring — single probe every 5s, serialized recovery after 3 consecutive failures or child exit.
• Renderer recovery — must stay unresponsive for 30s before window rebuild; responsive event cancels, healthy Harness stays alive.
• Watchdog — bounded 1s / 2s restart after abnormal disconnect; 3rd crash within 5 minutes opens circuit.
• Bounded shutdown — handshake with Watchdog, request Harness graceful termination, wait up to 8s before escalation.
• Bounded diagnostics — redacted, rotated 5×10 MB, not forever.
• No overlapping recovery — concurrent failures converge to one operation.
• No blind replay — healthy service is never killed, interrupted requests are never auto-replayed.

Modern desktop experience

• Self-contained host, system Node — Chromium / Harness / plugins / Watchdog bundled in .app, running on Node 22.19+ or 24+ (Node 23 is unsupported), installed to user data on first launch, auto-detected even under minimal GUI PATH.
• Official Harness surface — sessions, profiles, providers, workspace, and question flows remain official.
• Integrated settings — runtime status, restart, logs, and close behavior in General settings with official UI primitives.
• Native lifecycle — open, restart, logs, and quit from persistent tray/menu; close-to-tray or direct quit.
• System appearance — light/dark startup UI, platform title bar, official monochrome assets, reduced-motion support.
• Smooth navigation — View Transitions when available, CSS fallback otherwise, no forced layout.
• Workspace resilience — validated Standard switching and official session restoration.
• Opt-in LAN access — disabled by default; when enabled, an Electron-owned HTTP proxy listens on local interfaces while Harness stays on loopback. Empty password allows direct access from a reachable LAN device; a configured password triggers browser Basic Auth for HTTP and WebSocket traffic.
• Skills — Superpowers 6.2.0 installed to <DSH_HOME>/skills, never overwriting user-owned directories.
• Global Agent Protocol — <DSH_HOME>/AGENTS.md: auto-installed when absent, upgraded only while still app-managed, never overwriting user-owned, with timestamped backup switch via Use Bundled Global Prompt….
• Global dsh untouched — startup never runs npm install -g and never changes an existing user-managed global CLI.
• User-confirmed updates — SHA-256-verified assets only; Windows preserves the current NSIS directory, Linux AppImage replaces the persistent $APPIMAGE file, and Debian packages remain manual.
• Localized presets — anchored-standard / router-standard / router-spec with bilingual names, IDs unchanged.
• Safe experiment — Anchored Standard as a separate bundle, fails closed to Standard on maintained Harness 0.1.1-rc.2.code.1.

Feature matrix

Area	Included
Desktop host	Hardened window, startup page, native menus, tray
Harness	Code-DSH family 0.1.1-rc.2.code.1, loopback, single Home
V4 models	Official catalog and off / high / max
Stack	Skills, Goal / Plan / Workflow / Todo / Jobs / questions
Skills	Superpowers 6.2.0, never overwriting user
Global prompt	AGENTS.md ownership-safe install and backup switch
Global CLI	User-managed; never installed or modified by the app
Presets	Standard default, optional anchored / router
Recovery	Health probes, restart, renderer replacement, port retry
Watchdog	Independent IPC, bounded restart and circuit breaker
Plugins	Desktop, UI Motion, Model2, Find, Routing, Settings Tools, Plugin Market, etc.
Diagnostics	Startup evidence, runtime state, redacted rotated logs
Security	Sandboxed renderer, no Node integration, validated IPC
Packaging	macOS Universal DMG; Windows NSIS; Linux AppImage/deb

Routing suite

Bundled community dsh-routing-suite, auto-loaded on every launch:

• Offline snapshot — three pinned components (@dsh-external/dsh-super-injector, @dsh-external/dsh-mode-boost, router-standard + router-spec) inside app resources.
• Pinned baseline — injector 0.3.3 / mode-boost 0.1.0 / router-preset 0.2.0@eff787e, SHA-256 in build/routing-suite/versions.json.
• Public CLI reconciliation — via system Node + bundled pnpm dsh plugin --profile web add (desktop, ui-motion, model2, prompt-principles, vision-router, better-sidebar, LAN access, composition, Super Injector, Mode Boost, find-plugin, settings-tools, plugin-market). The maintained Harness owns manifest reconciliation. A validated app-owned marker skips repeated CLI additions only for an unchanged managed roster; a missing or mismatched marker, changed package root/identity, missing profile dependency, or foreign store runs reconciliation again. The complete maintained runtime provides the subagent packages; no linkOnly post-processing remains.
• Reviewed updates — only with new app release, SHA-256 verified before extraction, never downloading mutable code in background.
• Ownership-safe — never overwrites unrelated plugins or user-owned presets, legacy Home copy-only migrated.

Architecture

Figure 1 — Code Agent desktop architecture. Electron Main owns window/child/bridge; Harness owns sessions/protocol; Watchdog owns relaunch; Preload owns validation. See overview and lifecycle. Chinese: system-zh.svg

In one picture: host creates window, resolves system Node, reconciles plugins via the public CLI, starts maintained dsh web on loopback and health-checks with non-overlapping 5s probes; Preload is the only renderer↔main seam (preferences, lanAccess, runtime, updater, bundledPlugins); the Harness child uses DSH_HOME/~/.dsh; Watchdog restarts via IPC with bounded backoff; persistence stays outside .app.

Full boundaries in overview and lifecycle, light/dark adaptive.

Security model

• Sandboxed renderer, no Node integration.
• Only the fixed preferences, lanAccess, runtime, updater, and bundledPlugins preload groups.
• IPC payloads validated before desktop actions.
• Harness itself binds only to loopback. LAN access is disabled by default; an opt-in Electron reverse proxy may listen on 0.0.0.0. Empty password permits direct trusted-LAN access; a configured password uses browser Basic Auth for HTTP and WebSocket traffic. It is trusted-LAN HTTP only, with no Internet-exposure or TLS claim.
• Credentials stay in official Harness settings, never in bundle.
• Logs exclude credentials, Authorization, Cookie, prompts, and responses.
• External navigation allow / open-external policy.

Platform status

Platform	Target	BETA3 release gate
macOS	macOS 12+, Intel and Apple Silicon	Universal DMG native validation passed
Windows	Windows 10+, x64 and arm64	Native NSIS install/runtime validation passed
Linux	x64 and arm64	Native AppImage/deb validation passed

BETA6 is now GitHub Latest as an updater test release. Native Windows/Linux x64+arm64 and macOS Intel/Apple-Silicon install/runtime/no-Node validation passed in Run 33140759412. Older DHSC builds can receive BETA6 through Settings → General → Check for updates using the size/SHA-256 update manifest contract.

Install on macOS

Current package is unsigned. After copying DeepSeek Harness Code.app to /Applications, a trusting recipient may remove quarantine for this app only:

xattr -dr com.apple.quarantine "/Applications/DeepSeek Harness Code.app"

Do not disable Gatekeeper globally. See complete unsigned guide.

Build from source

Requirements

• Node.js 22.19+ or 24+ (toolchain and runtime; Node 23 is unsupported)
• pnpm 11.19.0 (via pinned command below)
• Platform-native packaging tools

git clone https://github.com/Code-DSH/deepseek-harness-code.git
cd deepseek-harness-code
npm exec --yes --package=pnpm@11.19.0 -- pnpm install --frozen-lockfile
npm exec --yes --package=pnpm@11.19.0 -- pnpm test

Build and launch:

npm exec --yes --package=pnpm@11.19.0 -- pnpm start

Packages:

npm exec --yes --package=pnpm@11.19.0 -- pnpm dist:mac
npm exec --yes --package=pnpm@11.19.0 -- pnpm dist:win
npm exec --yes --package=pnpm@11.19.0 -- pnpm dist:linux

Release packages and update-manifest.json are produced by GitHub Actions only after verification on a v* tag push; local dist:* is for verification only.

Verify

npm exec --yes --package=pnpm@11.19.0 -- pnpm build
npm exec --yes --package=pnpm@11.19.0 -- pnpm test
npm exec --yes --package=pnpm@11.19.0 -- pnpm check
npm exec --yes --package=pnpm@11.19.0 -- pnpm check:memory
node scripts/verify-macos-artifact.mjs release/DeepSeek-Harness-Code-*.dmg --universal

Documentation

• Project intent
• Architecture overview / Lifecycle
• Diagram (EN) · 架构图（中文）
• Testing strategy / Acceptance
• Troubleshooting / Unsigned install

Roadmap

• Reproducible durability benchmarks (5s probe / 30s renderer / 8s shutdown).
• Native Linux GA (AppImage/deb already CI-green).
• Paired Project2 validation for anchored tool surface.
• Non-replaying fault injection.
• Versioned, Skills-driven delivery.
• Upstream plugin API tracking through the pinned Code-DSH submodule and locally hashed 0.1.1-rc.2.code.1 family.

Contributing

Issues and PRs welcome. Runtime behavior changes should include focused tests and update canonical docs. Keep claims evidence-based; never attach keys, cookies, prompts, or responses.

Start with AGENTS.md and documentation index.

License

MIT License.

Acknowledgements

Built on the official DeepSeek Harness and Electron. DeepSeek created the foundation; this community project focuses on desktop lifecycle, integration, recovery, packaging, and long-running Code Agent usability.

Disclaimer

Community-maintained software. "DeepSeek" only identifies compatibility with upstream; no affiliation, endorsement, or official support is implied.