A settled top-level `read_image` call printed its raw attachment object as
literal text in the tool card — `{"type":"image","attachment":{…}}` —
instead of the image, because no presentation metadata told a client card
how to present the reference and the tool-card layer had no image concept.
Host: `read_image` declares an `output.presentationMeta` persisting
`{ path }` only. The attachment reference deliberately lives in the
settled result content — the single record a `tools/post-execute`
replacement rewrites — not in `meta`; the id is opaque and
provider-owned, checked for existence only.
Client: `imageCardModel` derives the card from the call head, the meta
path, the result's own image block, and a shape-matched envelope. ToolRow
gains an `image` card slot; the `read_image` toolview declares the
Tool-owned `tool.call.images` slot as its child and dispatches the
gallery through it. ui-chat down-threads the session-authorized loader
(`ChatNodeOwnerProps.loadImage`), so the tool layer supplies only derived
references plus the loader and never imports an attachment
implementation; ui-attachment fills the slot with its message gallery
renderer. The card keeps the envelope text below the gallery for the
no-attachment-plugin deployment. An image-bearing tool registers a keyed
toolview; the generic fallback keeps its flattened text. `read_image`
joins the read variant with its own locale title key; both rows share
`read-family-row.tsx`.
Verification: `read-image.spec.ts` (metadata projection, envelope by
shape, reference narrowing, real-execution round trip, rejection
branches incl. non-digest ids), `image-card.client.spec.tsx` (derivation,
row render site dispatching the slot, keyed registration with the
child-slot declaration, empty-slot fallbacks, media-type enum), keyless
snapshots (`read-image-gif` added; read-image/-dimension/-reencode
updated to the `{path}` meta), five injected-defect negative controls,
and a demo GIF recorded from this PR's head through the official
image-capable model.
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.