dsh-compaction-counter
A DeepSeek Harness plugin that shows how many times the current session's
context has been compacted, next to the context meter under the composer.
4 turns 432 steps · 168 tok/s 74.3M tok · Cache hit 95% 30% Compactions: 1
What it counts
One count per successful compaction of the current session.
| Event | Counted | Why |
|---|
compaction/summary | yes | Appended inside the synchronous commit step, together with the replacement body, so a failed attempt closes with compaction/end carrying an error and never produces a summary. |
compaction/end with error | no | A failed attempt records the error and no summary. |
compaction/prune | no | A tool-result prune is not a compaction of the conversation. |
| inherited prefix of a forked session | no | Those compactions belong to the parent session, not the fork. |
The count is a durable session projection, so it survives a reload and a
reopened session: the host recomputes it from the session log.
Install
From a local checkout:
dsh plugin --profile web add "link:<absolute path to this directory>"
The plugin ships its own bundle patch, so the installation appends it to the
profile's dsh.profile.bundles selection. Restart dsh web afterwards, then
hard-refresh the browser.
The plugin does not touch the compaction behavior, the compaction
configuration, or the platform bundle: it adds one projection unit and one
composer-dock entry.
How it works
Host half (index.js) registers one projection unit, compactionCount,
on ctx.sessionProjections. The unit is a pure fold over the committed
session events; the client receives its whole value through the standard
projection channel.
Client half (client.js) registers one entry into the platform's
conversation.composer.dock slot — the same official slot the shipped
activity and usage pills use. The entry reads the compactionCount projection
through the session standard useProjection seat, so it renders nothing when
the host half is not mounted.
Placement. The platform renders the whole dock slot before the standard
context ring, so a slot entry's own order cannot place the reading on the
ring's right — it always lands to the ring's left. The entry therefore also
sets the CSS order: 1 on its own element. The dock is a flex row whose
standard ring carries no order (the default 0), so this moves the reading
past the ring while the shipped pills keep theirs. The visual order then
differs from the DOM order, which is the accepted trade for a reading that is
not interactive.
The copy follows the browser's language preference, picked once at load
(Chinese for a zh primary subtag, English otherwise). It does not consult
the DSH Language setting, and a language change takes effect on reload.
Development
npm install
npm test # unit and host-integration tests
npm run check
tests/projection.test.mjs covers the fold in isolation. tests/host-integration.test.mjs
runs the unit against the real @deepseek-ai/dsh-session and
@deepseek-ai/dsh-session-projection packages, including the fork case.
zod
The plugin's own zod dependency is floored at ^4.6.6, the first release
carrying the fix for CVE-2023-54404 (uncontrolled resource consumption
through unbounded array validation). The plugin validates numbers and objects
only, so the vulnerable array path is not reachable here, but the floor keeps
a patched version in every install.
The overrides entry pins the same version for the transitive copies the DSH
development dependencies bring in, so the whole tree resolves to one patched
zod. It applies to this package's own install only; the DSH packages keep
their own zod pins.
License
MIT
