Redlines for agent-built UI

Pin the nits.Ship the craft.

Your agent ships the first cut: fast, functional, generic. nitpin gives the last 5% a place to land.

Download trial See how it works

The machine writes the first cut. It works. Then generic becomes crafted. nitpin is the redline between those two.

Freeze. Pin. Fix.

Press the hotkey. The window stops as pixels. Mark the nit, write the note, and your agent reads the issue from the local store.

Freeze the frame

Press ⇧⌘6 over any window: browser, Simulator, Electron, even a menu that vanishes when it loses focus. nitpin freezes the pixels and leaves the app alone.

Pin what's off

Drop pins and regions, then write what your eye caught: "button sits 3px low," "spacing tight here." One note can cover several spots. Reference images paste straight in.

Hand it to your agent

Your agent pulls the issue over MCP, sees the marked-up still, edits the code, and checks off each sub-issue. Or let nitpin dispatch several fixes at once.

The Cockpit keeps score.

Every pin becomes a sub-issue. Agents claim work, post progress, and resolve fixes while the backlog stays live on your desk.

nitpin · Cockpit LIVE
The difference

It works beyond the browser.

Browser widgets stop at the tab. nitpin freezes whatever is on your Mac: Simulator, native apps, Electron shells, popovers, and the browser too, with a quiet selector hint when it can get one.

Live web

An embedded browser you drive yourself. Freeze it like any window; nitpin records a selector hint for the element under the pin.

Live capture in nitpin with a pinned button and a quiet selector hint for the agent.

The iOS Simulator

Mark the SwiftUI app where it actually runs. Freeze a frame, pin the 3px, ship the fix.

Transient UI

Hover states, menus, and popovers, caught before they vanish.

nitpin menu-bar popover with capture controls and current project status.

Native & Electron

AppKit, Catalyst, Electron. If it is a macOS window, you can pin it.

Local-first project data. Your captures live in a plain file store on your Mac. Activation checks license and trial allowance state. nitpin reads pixels, the window title, and the Live DOM node you pinned; it never clicks, types, or navigates.

The loop

Triage without the spreadsheet.

nitpin groups the backlog, sizes the work, and gives each agent the screenshot crop it needs. You stay out of the routing weeds.

Cluster the nits

nitpin turns a noisy backlog into themes, writes a brief for each cluster, and sizes every fix.

Run agents in parallel

Related fixes stay in one session. Separate agents get separate git worktrees, so they do not collide.

Route by size

Small tweaks go fast. Bigger refactors get stronger models. Each fix starts from the marked region, not the whole screenshot.

Works with Claude Code, OpenAI Codex, OpenCode, and Pi. Keep your agent. nitpin gives it a clean MCP view of the local issue store.

Issues your agent can use.

The capture is human. The contract is machine-readable. The Cockpit shows what is open, claimed, fixed, and ready to revisit.

✓Issues & sub-issues

Each capture is an issue. Each marked note is a sub-issue with its own status and priority.

✓Parallel agents

Claims and git worktrees let several agents work at once without stepping on each other.

✓Triage & clusters

Group related nits by hand or with an agent, then hand off a whole cluster.

✓MCP-native

The nitpin reader plugs into Claude Code, OpenAI Codex, OpenCode, and Pi.

✓On-device titles

Issues name themselves with on-device Apple Intelligence. Screenshots and notes stay on disk.

✓Live, always

The Cockpit updates as agents work: claims appear, progress changes, sub-issues resolve.

Own it. No subscription.

Download the Mac app and try it on a real project. After 25 fixed issues, activate through your nitpin account. No subscription.

nitpin for Mac · license
$59 once

Fix 25 issues first. Activate when nitpin earns its place.

  • ✓ Full capture app: windows and Live
  • ✓ Unlimited issues, sub-issues & projects
  • ✓ Triage, parallel agents, live Cockpit
  • ✓ One year of updates included
  • ✓ macOS 26+ required
  • + Renew updates later for $29/yr, optional
Download trial
For your agent · included
Included

The nitpin MCP reader gives agents the local issue store, without app IPC.

  • ✓ Read and resolve sub-issues over MCP
  • ✓ Works in Claude Code, OpenAI Codex, OpenCode & Pi
  • ✓ One-line install into any harness
  • ✓ Local project data stays on your Mac

The app writes the issues. The reader gives agents the contract.

Sweat the details.
Ship the delight.

The first cut is machine-made. The final pass is yours.

Download trial