# DeepSeek Harness

> DeepSeek's open-source, plugin-based agent harness (dsh) with a local Web UI, a Python SDK and support for DeepSeek and third-party models.

- id: `deepseek-harness`
- category: Harnesses (`harnesses`)
- url: https://github.com/deepseek-ai/deepseek-harness
- repo: https://github.com/deepseek-ai/deepseek-harness
- docs: https://deepseek-harness.github.io/deepseek-harness/
- status: beta
- pricing: open-source
- license: MIT
- tags: coding-agents, plugins, web-ui, python-sdk, deepseek
- llms.txt: https://deepseek-harness.github.io/deepseek-harness/llms.txt
- auth: api-key
- access notes: Needs a model provider API key (DeepSeek or another provider) entered in Settings → Models.
- related: Claude Code (https://indexagentica.com/entries/claude-code/); OpenAI Codex CLI (https://indexagentica.com/entries/codex-cli/); OpenCode (https://indexagentica.com/entries/opencode/)
- sources: https://github.com/deepseek-ai/deepseek-harness , https://deepseek-harness.github.io/deepseek-harness/ , https://www.npmjs.com/package/@deepseek-ai/dsh , https://github.com/deepseek-ai/deepseek-harness/blob/master/SAFETY.md , https://deepseek-harness.github.io/deepseek-harness/en/guide/providers.md , https://deepseek-harness.github.io/deepseek-harness/en/guide/python-sdk.md
- added: 2026-10-31
- updated: 2026-10-31
- last verified: 2026-10-31
- featured in: Research memory libraries compared: A-MEM vs MemoryOS vs MemOS vs LightRAG (https://indexagentica.com/compare/research-memory-libraries/)
- maintainer: DeepSeek
- submitted by: agentica-curator
- page: https://indexagentica.com/entries/deepseek-harness/
- json: https://indexagentica.com/api/entries/deepseek-harness.json

Built on an "everything is a plugin" architecture using the Cordis framework. Run `npx @deepseek-ai/dsh web` to start the Web UI at http://127.0.0.1:3080, or build from source with pnpm. Models are configured in the UI: DeepSeek via an API key, plus shipped third-party providers (e.g. anthropic, openai, moonshotai, zai) or any custom model API. Includes a Python SDK (`pip install deepseek-harness-sdk`), an MCP client package with reference memory-MCP configs, and plugin markets; plugins are tagged `dsh-plugin` on GitHub. MIT licensed. It is a developer preview with breaking changes expected; the project's SAFETY.md says it has not been security-audited and should run with least privilege, ideally in a disposable VM or container. The npm package is at 0.2.1-rc.5 (Oct 2026).