dsh-vision-reasoner

A DeepSeek Harness plugin that lets a model put numbered marks on a picture and look at what it drew. A place is named in the picture's own pixels, read off a labelled grid, so nothing is converted from a preview and no call has to be expressed in the terms of an earlier one. It is not specific to any kind of picture: counting the people in a photograph is one use, checking which of two similar regions a note meant is another.

Tools

Tool	Purpose
camera_reset	Point the camera at the whole picture — one square window holding all of it, the picture drawn inside and the rest black — and see it.
camera_move	step: "next" walks the sweep in reading order, "previous" steps back, a direction steps one whole window, and to: [x, y] centres the window on a place read off the grid.
camera_zoom_in / camera_zoom_out	One ×2 or ÷2 step each, about the centre, times for several at once. The camera stays where it is left.
mark_add	Mark places by their coordinates, at: [x, y] in original pixels, with a radius r, a caption and a colour. The camera moves to the batch and the answer is a window around it.
mark_remove	Delete marks by number, e.g. [3, 7], when a mark is in the wrong place.
mark_edit	Move, resize, recaption or recolour marks by number, in one call.

Every picture comes back with a grid whose lines sit at round positions in the picture's own pixels — 100, 200, 500, depending on how closely it is being looked at — and every line is labelled with that number along all four edges. A number the model reads is a number it can use. Every result also lists the whole record, with the coordinates of every mark, so a mark placed twice, or in the wrong spot, is visible in the next answer rather than several calls later. The tools never count or judge what is in a picture: that is the model's statement to make.

The package also publishes a skill, vision-sweep-count: the workflow this tool set was built around — see the whole picture, sweep it window by window, mark as you read, read the window that comes back, count the record. A model reads a skill when a task matches one, which matters here because pointing inside reasoning is a mode a model does not enter on its own.

Install

dsh plugin --profile <name> add dsh-vision-reasoner

Or from the Web UI: Plugins → Add plugin, with the package name. The package declares dsh.bundle.patch → ./cordis.patch.yml (one Host row), which the profile loader applies the next time the profile loads. There is no build step and no install script.

The only dependency is sharp (Apache-2.0), which the harness already uses for every image a session attaches (@deepseek-ai/dsh-attachment-local depends on it), so a deployment that can run this plugin already has it. Nothing third-party is vendored: the icon and the two locale files are this package's own. Node ^22.19.0 || >=24.0.0.

How it is used

1. Look first. A place is named from what has been seen, and the tool descriptions say so before anything else. The grid on the returned picture is the only ruler: the picture is not cropped with another tool, and no position is read off another view of it, whose pixels are a different size.
2. Read the labels. The lines are at round numbers of original pixels, so a position is read by naming the line before a feature and estimating the gap — about a quarter of a step is as fine as the eye goes, which is why the grid steps finer as the view gets closer.
3. Mark the coordinates. mark_add takes at: [x, y], a radius r in the picture's own pixels, a caption and a colour. The camera moves to what was marked and the answer is a square window around those marks, with a cross at each centre and the record beside it.
4. Sweep in windows you keep. camera_zoom_in until a face is big enough to read, then walk the picture with camera_move and step: "next": the windows tile the picture from its centre, "next" goes left to right and then down, and every result says how far the sweep has got and which windows are left. A place read in a window already used is comparable with the last one.
5. Check, then correct. The marks are drawn in every view, so what is left unmarked in the window in front of you is what you have not dealt with, and the record beside it shows a number twice or a ring on nothing. mark_edit moves a mark that is nearly right and mark_remove deletes one that is not — at once, since a change comes back as a window around what it touched and a wrong ring misleads every view after it.

Behaviour

The record is not written to disk. Marks live in the session log. The harness logs every tool call with its arguments and its result, and the record is a fold of those events, rebuilt with the same pure functions the live call used. A call carries everything the fold needs — a place is a pair of pixels, a radius is a number of pixels, and the camera is a list of ways it was aimed — so a reopened session recovers the same record, and nothing appears beside your picture.

Each picture is written twice. The model receives an image block through the attachment service, the shape read_image sends, so the picture arrives with the call that drew it. The Web UI's preview needs a file, because it decides how to render a document from its extension and an attachment object has none; the PNG is therefore also written to <cwd>/.dsh-vision/<name>.png and reported workspace-relative in images[].path. That directory is the only thing this plugin writes, and only when there is a picture to show.

A missing picture is reported, not thrown. No attachment service, or a model that does not declare image input (the gate read_image applies), returns the text plus a note instead of an image block; so does a failed write. Anything merely unknown — an unresolvable route, an adapter error — attaches anyway, because withholding a picture over a failed lookup costs more than it protects.

Pictures are read through ctx.fs, so the sandbox decides what may be read.

The grid

• Lines sit at multiples of a round step — 10, 20, 50, 100, 200, 500 … — chosen as the coarsest step whose labels are still about 100 view pixels apart. A wide view and a close view therefore both stay readable, and neither changes what a number means.
• Every label is an original-image coordinate, on all four edges, whatever the view is. Nothing is scaled, and nothing has to be converted.
• Lines are drawn 2 pixels wide at minimum and scale with the view, because a one-pixel line is gone by the time the attachment pipeline has re-encoded the picture.
• Every view is rendered at the same longest side, so looking at a rectangle is never coarser than looking at the whole picture.
• The camera is a place, not an action. A look shows what is in front of the lens, zoom and move aim it, reset points it back at the whole picture, and every result says where it is — so a caller reads "closer, a little left" rather than inventing rectangles, and looking again needs no arguments at all.
• Marks are drawn by default, so the picture carries the record; marks: false gives a clean canvas for counting a place again from scratch.
• Every result counts the windows the camera has stopped in since the last reset, names the one it is in, and names the ones still left: an unswept corner is a word in the answer rather than something a caller has to keep in its head.
• The window line says how the drawing relates to the picture — drawn 1400x1400 (1.08x of the picture) — because a caller that reads the rendering as the picture itself is wrong by exactly that ratio. One session reported reading a "1540x1084 preview" while every number it had was in a 2600-pixel space, and concluded the mapping was ambiguous.
• Every view is the same shape: a 1400x1400 square. The picture is placed inside it at the scale that fits and whatever is left over is black, so no view can come back as a strip one face tall, and no two views are shaped differently from each other.
• The grid is always drawn: both axes are labelled along all four edges, the columns that run down and the rows that run across in different colours, and a row label keeps out of the band where the column labels write so a corner is not a fight between two numbers.
• A view's longest side is capped at 4096 pixels (MAX_VIEW_DIMENSION).

Limitations

• A mark is where the caller said it was. The grid makes a position readable to about a quarter of its step, and nothing more; a mark placed from the whole picture of a large photograph lands within tens of pixels, not within one.
• A record belongs to the session that made it. A subagent sees the marks of the session it was forked from; its parent does not see the subagent's. Two agents need one session to share a record.
• Labels need a font. Text is rendered by librsvg, so a machine with no fonts draws shapes but no digits.
• Text width is estimated, not measured, so a caption may be cut a character early. It never overflows its tile.
• A call that produced no result — a process killed mid-call — is left out of the replayed record. The model may have been told about a mark the replay does not have.
• A log written before this redesign does not replay. Its calls carry cell names where the arguments now hold coordinates, so the replay reports that it could not place them.
• Native presentation only. Under code execution (PTC) the calls are not logged as tool/call, so the fold does not see them.
• Checking is cheap, not automatic. Nothing forces a second look, and the ledger only reports where the camera has been: it says nothing about what a rectangle holds.

Development

node test/vision.test.mjs     # the grid, the places, the record, the pictures
node test/tools.test.mjs      # the Host half against a stand-in harness

The first checks the geometry (the grid steps in round pixels, a place is refused outside the picture, a ring is a radius in pixels), renders real PNGs, and drives every planning function. The second drives all four tools against a fake session and filesystem: it checks that every returned value satisfies its declared output schema, that a place is named in the picture's own pixels, and that the record is a fold — a committed call counts, a failed one does not, an unfinished one never happened.

tools/replay-session.mjs <session.v4.jsonl.zstd> [--png out.png] rebuilds a record from a stored session log with no harness in the loop, and can render it onto the picture it names. tools/inspect-region.mjs IMAGE X Y W H prints part of an image as ASCII. tools/row-css.mjs prints the harness's own tool-row CSS.

index.js is the Host half. lib/client.js is the browser half, which claims one transcript row per tool name. The module contracts are in docs/DESIGN.md.

MIT — see LICENSE.