Loopback

Pin feedback on the app you're building. Any coding agent claims it. The pin turns green when the fix is verified.

Loopback is the interactive feedback layer between real product usage and your coding agents: one script tag makes the app you're running locally commentable (Vercel-toolbar-style toolbar, element-anchored pins; deployed public sites go via the /ingest rails instead — see surface compatibility), every pin auto-captures the functional context — failing requests with response bodies, console trail, the route journey that led there, LLM run metadata, typed repro steps — and lands in one project-tagged queue that Claude Code, Codex, and Gemini CLI all work over MCP. When an agent's fix is verified, the pin turns green on the page, live.

Seeded demo capture (generated by scripts/screenshot.mjs): the contact form's backend bug pinned, claimed by claude-code, marked fixed with a linked change, verified — pin and badge green. The wrong AI answer is still amber/open.

Why

Coding agents can fix anything you can describe — but the loop back from real usage is missing. You notice a broken flow, screenshot it, re-describe it in a prompt, paste console output, explain which project it belongs to. Every time, for every agent. Vercel's comments have no public API; Claude Design's anchored comments are artifact-scoped; error trackers don't know your queue.

Loopback is that missing loop, built as a hub:

• One instance, all projects. Every item is tagged with a project slug in one shared SQLite DB (~/.loopback/loopback.db). Agents registered once per machine; consuming repos add only a widget tag and a slug.
• One queue, all agents. MCP is the interface, so Claude Code, Codex, and Gemini CLI are peers — same tools, same playbook, same audit trail.
• A pin is an anchor, not a scope. Pin a "broken" contact form and the agent gets the failing POST with its 500 response body — a frontend pin carries the backend root cause. Pin an AI answer and the run metadata (run_id, model, trace_url) rides along.

            CAPTURE                          THE HUB                            AGENTS
 ┌───────────────────────────┐   ┌─────────────────────────────┐   ┌─────────────────────────┐
 │ widget pin on any app     │──►│  loopback-mcp-server        │◄──│ Claude Code             │
 │  · console + network ride │   │   one shared SQLite DB      │   │ Codex          (peers)  │
 │  · 500 bodies captured    │   │   ~/.loopback/loopback.db   │   │ Gemini CLI              │
 │  · AI run context         │   │                             │   └────────────┬────────────┘
 ├───────────────────────────┤   │  stdio (per-agent spawn)    │                │
 │ POST /ingest              │──►│  --http on 127.0.0.1:7077   │     list → claim → fix →
 │  · CI hooks, cron,        │   │   (required for widgets)    │     link change → fixed →
 │    Sentry/PostHog pollers │   │                             │     verify → resolve
 └───────────────────────────┘   └──────────────┬──────────────┘                │
                                                │                               │
              pins turn green on the page ◄─────┴───── status write-back ◄──────┘

Run it per-invocation over stdio (each agent spawns it; same DB = same qu