Plan Canvas

# Plan Canvas

Review loop for plans and visual artifacts: you write the artifact, the human
reviews it in the browser — annotating the exact element they mean, chatting,
and delivering an **Approve plan / Request changes** verdict — while you block
on a single CLI call that returns their feedback as JSON.

Inspired by [lavish-axi](https://github.com/kunchenguid/lavish-axi); rebuilt
ECC-native around the `/plan` confirmation gate, with zero dependencies.

## When to Use

- You just wrote a plan artifact (`.claude/plans/*.plan.md` from `/plan`) and
  need the CONFIRM/approve decision — the canvas verdict replaces a typed
  "yes/proceed".
- The user should *point at* what to change: reviewing designs, comparisons,
  reports, or any local `.md` / `.html` artifact.
- The user asks for `/plan-canvas`, a visual review, or "open it in the browser".

Do NOT use for: code review of diffs (`/code-review`), running web apps, or
remote URLs. The canvas serves local artifact files only.

## How It Works

Invoke the CLI as `ecc-plan-canvas` — the bin shipped by the `ecc-universal`
package (on PATH after a global/plugin install; `node "$CLAUDE_PLUGIN_ROOT/scripts/plan-canvas.js"`
also works for plugin installs). Run it from the project you are reviewing in;
it works from any working directory. It manages a detached loopback server
(`127.0.0.1:4517`) shared by all sessions, keyed by artifact path — no session
ids to track.