Sharing a canvas

Live multiplayer sessions with --share.

--share hosts your canvas as a live multiplayer session. Coworkers open a link in a plain browser — no account, no install — see the live canvas, and can draw on it; their edits stream back and land in diagram.excalidraw like your own.

Start a shared session

npx coopcli login                                        # once per machine
specsketch ./openspec/changes/new-feature-change --share

The CLI prints a link like https://coopcli.com/products/specsketch/s/<id>?k=<token>. The top bar shows a live pill with the participant count and a copy-link button.

How it hangs together

• The host needs a CoopCLI account (npx coopcli login); guests never do.
• The link itself is the capability: anyone holding it can view and edit until the session ends. The server stores only a hash of the link token.
• The local server still binds to 127.0.0.1 only — sharing runs over a single outbound connection from the CLI to api.coopcli.com (a per-session Durable Object). Your CoopCLI API key never reaches any browser.