dsh-context-explorer
See the context a Session submits to its model in the DeepSeek Harness Web UI: the system prompt, the tool schemas and every message, drawn as a grid of token squares.
The plugin will be installed here. Keep web if you are unsure.
npx -y @deepseek-ai/dsh plugin --profile web add github:LionNatsu/dsh-context-explorer#f39e7ba1f8c2baf100d6101cab9135cc6ba6424a
Context Explorer is published as dsh-context-explorer and currently resolves to version 0.1.1. The Hub verifies its manifest and preserves the exact installation source for reproducible installs.
A panel for DeepSeek Harness that shows what a Session actually sends to its model: the rendered system prompt, the tool schemas, and every message, drawn as a grid of token squares. It appears as a tab in the Web UI's right sidebar, titled 上下文 / Context.
One square is one slice of the context window, painted with the kind of content holding most of it; the dark squares past the end are free space. Above the grid, the chips are the legend and the filter; below it, every region is a row, and a row opens the text the model receives for that region.
This is an unofficial third-party plugin, not affiliated with or endorsed by
DeepSeek. MIT licensed — see LICENSE; THIRD_PARTY_NOTICES.md
records the two files reproduced from DeepSeek projects (estimate.js, serve.js).
dsh plugin --profile <name> add dsh-context-explorer
The Plugins page: Add plugin, the package name typed in, then Install
The same install is available from the Web UI's Plugins page: Add plugin, then the package name, a GitHub address, or a local directory path.
dsh plugin forwards its arguments to pnpm in that profile, so the flag names the
profile to install into. The package declares dsh.bundle.patch →
./cordis.patch.yml, so the profile loader applies its one host row the next time
the profile loads. The runtime files are plain checked-in JavaScript with no build
step and no install script, so a github: install needs no build permission. Node
^22.19.0 or >=24.0.0. locale/*.json carry the display name and description
per language (上下文浏览器 / Context Explorer). Verified against
@deepseek-ai/dsh 0.2.0-rc.2; the plugin declares no version gate, so a Harness
release that moves these extension points would show up as a missing or empty
panel rather than a refused install. A Host-half change needs a server restart;
the browser half reloads on its own.
A headline. 已用 {used} / {total}: used is the prompt size the provider
reported for the last request, and until a call reports one it is the panel's own
total. total is the context window, or — when the host has no window yet. The
tooltip says which figure is which.
Composition chips. One per kind of content present, heaviest first: an 8×8 swatch in that kind's colour, the kind's name, its token total and its share of the panel total. They wrap, and they double as the grid's legend. Clicking a chip filters the list to that kind; clicking it again clears the filter.
The grid. The whole context window, not just the part in use, as squares each covering an equal slice of the window. Occupied squares carry the colour of the kind holding most of that slice; a slice with at least 35% held by a second kind is drawn as a diagonal blend; the space past the end of the context is drawn flat as free space. Squares are 7 device pixels on a side with a 1-pixel gap, so every square paints the same size on any display scale. Hovering names the kind or kinds. Clicking a square opens the region that holds most of it.
The list. One row per region, in the order the model sees them: colour swatch,
a one-line summary, a 已截断 / clipped badge on a closed row whose fragment was
cut, and the region's token figure with its share. A figure the provider counted is
printed bare; this plugin's estimate carries ≈. The summary answers "what is this
region" before it is opened, because the raw text often does not: a turn that only
called tools is named by those calls (list_agents, edit(…\package.json)), a
JSON result by its leading scalar fields (timedOut: false), anything else by its
first line of prose. Clicking a row opens the region's
own fragment of the prompt the model receives — role markers and all — rather than
a summary of it; the badge gives way to detail.clippedNote in the body, so the
fact is stated once. A count and a toggle switch the list between model order and size
order.
With nothing to draw — no published view yet, or a view with no regions — the panel says so instead of an empty shell. A fold failure prints above the headline. A rendering error replaces the tab rather than leaving a blank panel.
The headline is the provider's own count of the last request. Each region's figure
is the provider's count where one covers that region, and this plugin's estimate
otherwise — marked ≈. Two things are measured: an answer's own size, when the
report states the output it was generated with, and a message that is the only one
in a request window, which is what the prompt grew by less the previous answer.
The system prompt, the tool envelope, a compaction summary, a window holding
several messages, and anything appended after the last report have normally no
provider count of their own, so they stay estimated.
The estimate is the Harness's own fixed heuristic, the same one its context meter uses: one token per four UTF-16 code units, plus four per content block and four per message. It prices content and not wire framing, and it drifts with the language of the text, so read an estimated figure as composition, not as a bill.
serve.js transcribes the published serving implementation so the
panel can show a region in the form the model receives;
tools/prompt-golden.mjs holds that transcription byte for byte against the
official open-weights encoder. Treat it as what that implementation renders.## Tools block. A message's fragment is capped at
4000 UTF-16 code units and spent in the order the prompt spends it; a region whose
fragment was cut is marked clipped and its expansion says only the beginning was
kept. The row's summary is bounded separately at 400 code units, and it is a
reading aid rather than the text: the region's own fragment is what the row opens.index.js, serve.js and estimate.js are imported when the process starts, and
the shipped hmr row runs with root: [], which watches configuration rather than
source modules. Removing and re-adding the plugin reconciles the composition but
reuses the module already in memory, so it does not pick up an edit to the same
file either. Three things do: restart; give that row the directory to watch
(- id: hmr with config: { root: ["…"] }) in the profile patch; or install a
copy at a new path, which is what publishing a new version does. Installing,
removing, enabling or disabling a plugin is a configuration change instead: with
HMR present the manager applies it live and reports which happened
(application: applied, otherwise restart-required). client.js is served
through the client module system, which reloads the browser half on its own.One npm package, one plugin, both halves in it:
| Path | Role |
|---|---|
index.js | Host half: the sessionProjections unit that folds a session into the view |
client.js | Browser half: the tab, the grid, the region list |
serve.js | The served-prompt renderer, transcribed from the DeepSeek serving implementation |
estimate.js | The token estimator, a local copy of the shipped one |
package.json, cordis.patch.yml | Manifest and the bundle patch (one host row) |
icon.svg, locale/*.json | The mark, and the name and description per language |
docs/prompt-injection-format.md | How a Harness conversation becomes prompt text |
docs/screenshots/ | The two images above, kept out of the published tarball |
tools/ | Checks and diagnostics |
The host half imports nothing but its sibling estimate.js and serve.js, which
is what lets a profile link this directory directly instead of installing a
published copy.
Run from the repository root; each exits non-zero on failure.
node tools/check-bundle.mjs — packaging and bindings: the manifest ships every
runtime file, both halves resolve through it, every class the stylesheet styles is
applied by an element, and no declaration shadows a builtin.node tools/context-explorer.test.mjs — the host fold: region order, the
accounting behind every share, the prompt surviving a rewrite, the truncation
flag, and agreement with the installed estimator.node tools/context-explorer.contract.mjs — the wire the two halves share:
locale keys, the fields each half names, the grid's square budget, the palette.node tools/context-explorer.helpers.test.mjs — the browser half's pure helpers,
loaded through its real module registration.node tools/prompt-golden.mjs — serve.js against the official encoder, byte
for byte.tools/replay-session.mjs <session.v4.jsonl.zstd> replays a real log, and
tools/activation-probe.mjs mounts the plugin as the Loader does and asserts the
projection key reaches a snapshot.