Lastline

As long-running coding agents autonoumously ship larger and larger pull requests, the bottleneck shifts from writing code to reviewing it. These agents make product decisions across entire user flows, not just single screens. They decide how a modal behaves, how a page looks in light mode, and how users move through the product. Today, reviewing that work is still painfully manual. A human has to open the preview, walk through the app step by step, compare what they see against what they expected, capture screenshots, and file bugs. We built Lastline, an QA agent for AI-generated pull-requests. When a pull request hits a repo, Lastline is triggered by a GitHub webhook. It creates a QA plan, runs the product with Playwright, records the important user flows, and stitches them into one review video. That video is sent to the human reviewer on Telegram. The reviewer can leave simple timestamped feedback, and Lastline turns that into structured GitHub issues with screenshots, timestamps, and PR context.