`_check_done_value` and `_encode_json_plain` pushed one stack entry per child (plus a separator marker, and `dict.items()` materialized as a list), so the bookkeeping scaled with the value's WIDTH rather than its depth. A value the byte meter admits could then die on the walk's own frames: a flat `[0] * 2_000_000` serializes to 4.0 MB, but measured peaks were 145.2 MB in the meter and 114.7 MB in the encoder — 28.7x the serialized size, far past the 12x the load-time address-space gate reserves. Each container now pushes ONE cursor frame that pulls its children one at a time and writes into a shared `io.StringIO`, so the output string is the only width-proportional allocation and the caller already metered its size. Measured on the same value: 0.0 MB in the meter and 9.0 MB in the encoder (2.3x), with identical verdicts.
DeepSeek Harness
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DeepSeek Harness (dsh) is an open-source agent harness developed by DeepSeek AI.
It is built on an everything-is-a-plugin architecture and powered by Cordis, whose design is described in A Programming Paradigm for Spatiotemporal Composability.
Documentation: https://deepseek-harness.github.io/deepseek-harness/
Developer preview
DeepSeek Harness is in developer preview and iterating rapidly. THERE WILL BE COMPATIBILITY-BREAKING CHANGES.
Review the safety notice before running the project.
Run
Run from npm
Install Node.js, then run:
npx @deepseek-ai/dsh web
The command starts the Web UI at http://127.0.0.1:3080 by default and opens it in the default browser for a local launch. An SSH launch only prints the host URL because the SSH client or editor owns the local forwarded address. Pass --no-open to run the server without opening a browser. See Web UI guide.
Run from source
To run from a repository checkout:
git clone https://github.com/deepseek-ai/deepseek-harness.git
cd deepseek-harness
pnpm install
pnpm run build
pnpm dsh web
pnpm run build prepares the repository artifacts. pnpm dsh web uses those built artifacts without rebuilding.
Community and support
- Submit feedback or bug reports through GitHub Discussions.
- Add the
dsh-plugintopic to your plugin repository for discoverability. - Join DeepSeek Harness Discord community.
Contributing
See CONTRIBUTING.md.
Development
Start with the development guide and architecture documentation.
For agents, follow AGENTS.md.
License
Third-party dependencies and their licenses are disclosed in THIRD_PARTY_NOTICES.md.