v0.1.0

sideshow gives terminal coding agents a browser to draw in. Agents publish HTML — diagrams, UI sketches, charts, interactive explainers — while they work; you watch them render live and comment back, and your comments are delivered to the agent in its terminal.

This is the first release. npm install -g sideshow, then npx sideshow serve --open.

The surface

• A live viewer organized as agent sessions → snippets → comment threads.
• Snippets are versioned: updating one keeps its history, and you can flip between versions in the viewer.
• Each snippet renders in a sandboxed iframe (sandbox="allow-scripts", no same-origin) behind a CSP that limits external resources to a small CDN allowlist. Light/dark theming via CSS variables.

Three ways for agents to connect

• CLI — the zero-dependency sideshow command (publish, update, wait, comment, list, …). Works with any agent that has a shell; sessions group automatically per conversation.
• MCP — publish_snippet, update_snippet, wait_for_feedback, reply_to_user, list_snippets, get_design_guide, over stdio or streamable HTTP at /mcp (no local process needed).
• Plain HTTP — REST endpoints plus a long-poll comments endpoint.

The feedback loop

Agents block on sideshow wait / wait_for_feedback (long-poll, no extra infrastructure) and pick up your browser comments as instructions; they can reply directly into the thread.

Run it locally or on Cloudflare

• Local: npx sideshow serve --open.
• Cloud: npm run deploy puts the entire app in a Cloudflare Durable Object with SQLite storage — same product, same tools, reached by pointing SIDESHOW_URL / SIDESHOW_TOKEN at the deployment. Token auth guards deployed instances (bearer for APIs, a /?key= cookie for the viewer); /guide and /setup stay public.

How agents learn it

MCP clients receive usage instructions automatically. Everyone else gets the paste-able block at /setup (curl -s …/setup >> AGENTS.md), and Claude Code users can install the bundled skill in skills/sideshow/.