pixelduet

io.github.kimjungminn24Published by GitHub account kimjungminn24v1.0.0Updated Nov 3, 2026

A pixel canvas you share with the model: watch it draw live, pause, edit, and hand the brush back.

VerifiedSTDIODesktop onlyMedia & Design

Overview

pixelduet's local MCP server; no sign-in required; STDIO; 18 tools.

No AI overview yet: these facts come from the registry entry and the server itself.

Installation

In SourceWeft

  1. Open pixelduet in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

pixelduet

한국어

A pixel canvas shared by a model and a person. The model draws stroke by stroke while you watch in the browser. Pause it, take the brush, change things, leave a note, and hand the brush back. The reply to its next stroke tells it what you did.

[The model draws a potion flask stroke by stroke, the person pauses it, fills the liquid pink and leaves a note, and the model shades around the change and finishes]

Install

npx -y pixelduet version

or

go install github.com/kimjungminn24/pixel-duet@latest

or download a binary from the Releases page. Linux, macOS and Windows.

Quick start

npx -y pixelduet

starts the canvas server and the browser viewer and opens the viewer.

The browser is your side. Claude can't look at a web page, so it gets its own way in: the bridge, an MCP server that hands it tools like draw_line and read_pixels. Both reach the same canvas, and a stroke from one side shows up on the other.

    you, in the browser             Claude Code             |                           |           HTTP                   MCP (pixelduet bridge)             |                           |             `-----> canvas server <-----'

Connect Claude Code once:

claude mcp add -s user pixelduet -- npx -y pixelduet bridge

-s user makes it available in every project. Without it the bridge is only there in the folder you ran the command in.

If nothing is running when a session starts, the bridge starts the servers itself. Then ask Claude for a drawing:

Draw a frog on pixelduet.

Claude tells you the viewer's address if your browser is not open on it yet.

In a checkout of this repository, go run . replaces npx -y pixelduet and Claude Code picks the bridge up from .mcp.json.

Other MCP clients

The bridge is an MCP server over stdio. Codex CLI:

codex mcp add pixelduet -- npx -y pixelduet bridge

or in ~/.codex/config.toml:

[mcp_servers.pixelduet]command = "npx"args = ["-y", "pixelduet", "bridge"]

On Windows use command = "cmd" and args = ["/c", "npx", "-y", "pixelduet", "bridge"].

Two things to check with a new client:

  • The drawing rules are sent as the server's instructions. If the client drops them, npx -y pixelduet rules >> AGENTS.md restores them.
  • get_canvas returns a PNG. A client that does not pass images through leaves the model with read_pixels digits only.

Without MCP, anything that can open a TCP socket can draw. The protocol is in internal/proto/proto.go.

The handoff

  1. The model draws one stroke per call and narrates in the log.

  2. You press pause. The model's next stroke is held.

  3. You edit pixels, pick colors, leave a note. Your edits never wait.

  4. You press resume. The held stroke lands and its reply says:

    ok changed=1 waited=12s edits=5 box=9,8-13,10 note=make the eyes bigger

  5. The model reads the canvas, keeps your edits, and continues.

Talking

Type into the box under the log at any time.

  • While the model is drawing, your words arrive on the reply to its next stroke.
  • When it has nothing to draw, it calls listen, which returns when you say something.

Notes queue up in order. The model answers in the same log with say.

The viewer

Toolspen B, eraser E, line L, rect R, circle O, filled rect U, filled circle P, fill F, pick I
Canvaszoom slider, fit, pan H or Space+drag, pixel grid G, undo Ctrl+Z, size 32/64/128
Palette32 DB32 slots; edit a slot and every pixel using it changes
Modelplay/pause, a speed slider that adds up to 3s between strokes
Saveto the server's gallery folder, or to a folder you pick (Chrome, Edge)
LanguageKorean or English, following the browser; a header button switches; ?lang=en forces one

What the model gets

  • get_canvas: the canvas as a PNG, whole or a region, plus a count of pixels that differ from their mirror image.
  • read_pixels: a region as digits, or as run-length rows when shorter.
  • draw_pixels, draw_line, draw_rect, draw_ellipse, fill_area, each with mirror to paint the reflection across the center line.
  • shade, highlight, outline, dither: finishing passes on what is already painted.
  • list_sprites, view_sprite, save_sprite, stamp: a gallery of saved grids in sprites/.
  • say, listen: the chat.
  • Drawing rules, sent on connect: plan proportions in numbers, silhouette first, check the picture after every step, one light source, ask before going on. See internal/bridge/rules.go.

Keeping it small

  • read_pixels compresses with run-length encoding when that comes out shorter: a run of one color becomes 4*16, and identical rows fold into y3-9:. The 128x128 frog goes from 16,512 characters to 3,760, under a quarter.
  • Lines, rectangles and ellipses take two corners or a center and two radii. A filled circle can cover hundreds of pixels and the model still sends four numbers.

How it fits together

pixelduet serve            owns the canvas  |- pixelduet web         browser <-> HTTP/SSE <-> line protocol  `- pixelduet bridge      MCP client <-> tools <-> line protocol

pixelduet alone runs serve and web in one process. The bridge does the same when no server answers.

The canvas is a grid of palette indices, one character per pixel (0 empty, 1-w colors), the same on the wire, in save files, and in what the model reads. The viewer is HTML, CSS and ES modules under internal/web/static/, embedded in the binary.

Tests

go test ./...node --test test/*.test.mjs

See CONTRIBUTING.md.

License

MIT. See LICENSE.

Source: README.md at commit 5611ba2

Tools

18

clear_canvas

Wipe the whole canvas back to transparent. Never use it to erase what the person drew.

Takes no parameters.

dither

Checker two colors inside a strip: every other pixel of from becomes to. It makes a tone between two palette colors.

Parametershrequiredwrequiredxrequiredyrequiredtorequiredfromrequired

draw_ellipse

Paint an ellipse given its center and radii, outline or filled. Centers take halves, so cx 15.5 is the middle of a 32 wide canvas, and rx=ry=3 gives a 7 wide circle.

Parameterscxrequiredcyrequiredrxrequiredryrequiredcolorrequiredfilledmirror

draw_line

Paint a straight line of one color from (x0,y0) to (x1,y1), one pixel thick with no gaps. mirror also paints the reflection across the vertical center.

Parametersx0requiredx1requiredy0requiredy1requiredcolorrequiredmirror

draw_pixels

Paint one stroke of a single color, pixel by pixel. mirror also paints the reflection across the vertical center. If the canvas is paused the call waits, and its reply says what the person changed and said.

Parameterscolorrequiredmirrorpointsrequired

draw_rect

Paint a rectangle given two opposite corners, outline or filled.

Parametersx0requiredx1requiredy0requiredy1requiredcolorrequiredfilledmirror

fill_area

Flood fill from one pixel, replacing the connected patch of its color.

Parametersxrequiredyrequiredcolorrequired

get_canvas

The canvas as a picture, with its size, whether it is paused, and how many pixels differ from their mirror image. Name a region with x,y,w,h to fill the same picture with just that part: a 14 wide face comes back at 36 screen pixels per canvas pixel instead of 8, which is the only way to judge an eye.

Parametershwxy

highlight

Lighten everything painted on the side facing the light, one step up the palette (green to yellow, navy to blue, grey to silver). The opposite of shade; give it the same light.

Parametershwxylightwidth

list_sprites

List the gallery: pictures saved from earlier sessions because the person liked them.

Takes no parameters.

listen

Wait for the person to say something in the chat beside the canvas. It comes back empty if the wait window runs out.

Takes no parameters.

outline

Ring everything painted with a one pixel border, or take the ring off with off. color 1 is the classic black border; no color at all gives each shape the darker shade of its own fill. It outlines against transparency, so it runs before any background fill, and calling it twice rings the first ring.

Parametershwxyoffcolor

read_pixels

The canvas as digits, for exact coordinates: a picture cannot tell you whether an eye is in column 11 or 12, this can. Name a region with x,y,w,h; none means the whole canvas. A wide read comes back as run-length rows unless you ask otherwise.

Parametershwxycompact

save_sprite

Save the canvas, or a region of it, to the gallery under a name.

Parametershwxynamerequired

say

Show one short line in the log panel beside the canvas. What the person types appears in the same place.

Parameterstextrequired

shade

Darken everything painted on the side facing away from the light, one step down the palette (green to dark green, blue to navy, orange to brown). Boundaries between two different fills are left alone, so a belly stays a belly.

Parametershwxylightwidth

stamp

Place a saved sprite with its top-left corner at (x,y). Its empty pixels leave what is under them alone.

Parametersxrequiredyrequirednamerequired

view_sprite

One saved sprite, as a picture and as digits.

Parametersnamerequired

Version history

1
  1. v1.0.0LatestNov 3, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts
  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts