Yichen Jiang
f376ee23d1
Three defects surfaced while driving the Models page. A hand-declared model needed an explicit contextWindow and maxTokens, but a provider listing usually returns ids and nothing else — so the page happily wrote a profile the adapter then rejected, which took the whole namespace down silently. Capacities now fall back to the route's `defaultContextWindow` (262,144) and `defaultMaxTokens` (32,768). Both are guesses by construction, which is why they are route fields a deployment corrects once rather than constants buried in the adapter; the fallback sizes the model and never becomes a per-request cap. That silent failure was the second defect. A schema-valid profile the adapter could not serve was stored and only rejected later, disabling every route in the namespace with nothing said. `dsh-settings` gains an optional `validate` on registration — a check for what a schema cannot express — and `llm-pi-ai` refuses an unserviceable section at the write that produced it. A stored section that fails keeps the namespace's last good value, as a schema failure already did, so an externally edited document still cannot strand the owner. The plugin's own last-good fallback goes with it: nothing reaching it can fail any more. Third, a model with no reasoning metadata advertised the single level `off`, which pi-ai translates to *omitting* the reasoning option — the same request naming no effort produces. Selecting it disabled nothing, so a provider whose default is to think kept thinking with `off` shown as selected. Such a model now reports no reasoning capability at all, which is the seam's way of saying the control is unavailable, and the per-model `reasoning` flag is gone: without a thinkingLevelMap to spell levels it could only invent them. The protocol table narrows to the three a hand-declared route reaches today, most-reached first so a surface offering a choice defaults to the one gateways actually speak.
DeepSeek Harness
English | 中文
DeepSeek Harness (dsh) is an open-source coding agent built on the DeepSeek Harness SDK.
It uses an architecture where everything is a plugin.
Internal testing notice
DeepSeek Harness is under internal testing. Features and interfaces may change.
The internal build uploads all Session Logs by default to help diagnose reported problems. Set DSH_TELEMETRY_DISABLED=1 to disable telemetry. Send feedback through the internal WeChat group.
Install
Clone the repository, then run the installer:
git clone <repo-url>
cd deepseek-harness
scripts/install.sh
The installer requires git and Node ^22.19 || >=24, offers to install pnpm when it is missing, prompts for a DeepSeek API key, builds the required repository artifacts, and launches the Web UI.
The default active checkout is ~/.dsh/source/current, and the launcher is linked into ~/.local/bin. Re-run the installer to update. scripts/install.sh owns alternate locations, update mechanics, and recovery options.
Use DeepSeek Harness
Web UI
For the recommended local interface, choose Web UI when the installer finishes. To start it later, or after updating the active checkout, build the repository and run:
(cd ~/.dsh/source/current && pnpm run build)
dsh web
The path above is the installer's default. If you set DSH_SOURCE or DSH_CURRENT, or reused an existing checkout, replace ~/.dsh/source/current with that checkout path; see scripts/install.sh for details. The Web UI is served at http://127.0.0.1:3080 by default.
Configured runtime
Raw dsh requires a patch-list configuration applied over the shipped base:
dsh --config ./app.cordis.yml
The CLI contract describes the base, overlay semantics, and config dump commands.
Headless
Run one task, print the final answer, and exit:
dsh -p "summarize this workspace"
Automation and SDKs
From a source checkout with DEEPSEEK_API_KEY in the environment or its root .env, start the ACP automation server:
pnpm run demo:acp
The Python SDK drives a bundled JSON-RPC runtime. The examples cover the runnable headless, ACP, JSON-RPC, Code Mode, and self-referential compositions.
Why DeepSeek Harness
Built-in capabilities cover file reading, editing, and search; shell and persistent PTY execution; reusable skills; task tracking, goals, plans, todos, and background tasks; subagents and workflows; sandboxing and approvals; settings and credentials; persistent, resumable, forkable, and queryable sessions; LSP and web access; context compaction; and telemetry. Each composition selects the subset appropriate to its surface. The Web UI includes Plan Mode.
- Everything is a plugin. Models, tools, policies, storage, context management, and interfaces are composable Cordis plugins, so deployments can extend or replace behavior without forking the agent loop. See the architecture for the underlying design.
- Runs are reconstructable. Anything visible to the model is logged in the authoritative session stream; persistence, resume/fork/query, replay, telemetry, and UIs derive from the same events. See the session-log architecture.
- Code Mode (opt-in). It exposes a
run_codetool and a generated TypeScript SDK; only program output re-enters model context. See Code Mode. - Self-referential Cordis tools are opt-in. They let the agent inspect its live runtime and mount or unmount plugins while it runs. See the Cordis tools.
Community
Follow DeepSeek Harness on Twitter for project updates.
Development
Start with the development guide and read the architecture before changing packages.
For agents, follow AGENTS.md.
DeepSeek Harness is currently in internal testing.
License
Third-party dependencies and their licenses are disclosed in THIRD_PARTY_NOTICES.md.