Tianyi Cui
df0145271d
The projection-cache writer preserves lossless JSON, including own keys named __proto__. The z.json reader rebuilds objects and drops those keys, so opening the same stored checkpoint can produce state different from Session replay. This affects embedded result metadata and opaque extension payloads as well as other projection state. Validate with the existing isJsonValue predicate used by the writer's snapshotJsonValue rules. It rejects non-JSON and lossy values without rebuilding valid borrowed records. Keep the stored representation and domain version unchanged: this is a reader correction, not a new cache format. Exercise a fixture captured through the actual pre-fix writer with a real StorageDomain open, rewrite, close and reopen. Preserve nested prototype-named keys and retain negative coverage for invalid JSON values. Document why this validation matches the storage-domain immutable borrowed-value contract. Use neutral arbitrary JSON in the new opaque-state fixture so this reader regression stays independent of Session message representation. Its own prototype-named keys and nested arrays are unchanged in purpose. Confirm the fixture matches the pre-fix StorageDomain writer output and that the old z.json reader fails its key-preservation assertion. No released Session recordings or historical cache fixtures are edited.
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.
Citation
@misc{deepseek-harness2026,
title={DeepSeek Harness: Everything is a Plugin},
author={DeepSeek-AI},
year={2026},
publisher={GitHub},
howpublished={\url{https://github.com/deepseek-ai/deepseek-harness}},
}
License
Third-party dependencies and their licenses are disclosed in THIRD_PARTY_NOTICES.md.