Paint → smiley → email

Hand a computer-use agent one sentence and it drives the whole Windows desktop with MCEC: open Paint, draw a smiley, copy it, start a new email, and paste the drawing in. A capability demo, not a fixed artifact.

Paint to smiley to email, driven by MCEC

Flavor: Prompt demo. One of the worked Examples; the shared bootstrap, MCP envelope, and targeting gotchas live there and aren’t repeated here.

Recording note: to avoid putting a real inbox in a public GIF, the recording pastes into a neutral mock “New message” page (a local HTML compose form in a chromeless browser window). A real mail client works identically; only the paste target differs.

The prompt

Open Microsoft Paint, draw a smiley face, select it all and copy it to the clipboard, start a new email message, and paste the smiley into the body. Don’t send it, just leave the draft open.

That is the entire input. A capable agent with MCEC mounted plans and executes the rest; the recipe below is a reference for what a good run does, not a script the agent has to be handed.

Preconditions

Recipe

The agent improvises from the prompt; a known-good path is:

  1. Open Paint. launch { path: "mspaint.exe" } (or Win+S → type Paint → Enter). Wait for the window, then query { process: "mspaint" } for the canvas bounds.
  2. Focus the canvas. A coordinate click inside the canvas so drawing input lands there.
  3. Draw the smiley with the pencil/brush, each stroke a drag with a multi-point path (press → move along the path → release), the same technique the hero GIF uses to circle the title bar:
    • Face: a closed circle path of points around the canvas center.
    • Eyes: two short drags (or clicks) above center.
    • Smile: an upward arc path below center.
  4. Select all and copy. Ctrl+A then Ctrl+C, sent as real VK+modifier commands (MCEC’s built-in ctrl-x shows the shape; define ctrl-a/ctrl-c as SendInput commands with Vk+Ctrl). Do not try to fake an accelerator with shiftdown:ctrl + chars:a: chars: injects a character, which does not reliably trigger an app’s Ctrl+key accelerator, so the copy silently produces nothing. This puts the canvas bitmap on the clipboard. (clipboard { action: "get" } can confirm an image is present.)
  5. Start a new email. launch { path: "mailto:" } opens a blank compose window in the default mail client (or open the mail app and click New mail).
  6. Paste into the body. click the message body to focus it, then ctrl-v (again a real VK+modifier command). A rich composer pastes the bitmap inline.
  7. Stop at the draft. Leave the compose window open; do not send. (For a recording, record the desktop region from step 1 and stop here.)

Expected result

A mail-compose window open with a hand-drawn smiley pasted into the body, and the draft left unsent. As a prompt demo the exact pixels vary run to run; success is “the smiley made it from Paint’s canvas, through the clipboard, into an email body, hands-free.”

Gotchas