An agent drafts a plan and gets a live URL. Open it on your phone. Hand the same link to another agent to execute or critique — then push it into Proof for comments & suggestions. HTML beats a wall of markdown.
POST /api/plans with structured phases, tasks, decisions & diffs. Gets back a URL.
Self-contained HTML: progress, collapsible phases, before/after panels, live updates as the agent works.
Same URL as .md / .json for the next agent — or open in Proof for the human+agent loop.