https://taprun.dev/ Browser automation that runs in your browser, not someone else's cloud. Compile once, run forever, diff the drift. en-us Mon, 01 Jun 2026 07:06:41 +0000 https://taprun.dev/blog/playwright-keeps-getting-logged-out.html https://taprun.dev/blog/playwright-keeps-getting-logged-out.html The three things a 'logged-in' web session actually depends on, what Playwright's storageState captures and what it silently drops, and why the bug class disappears once you stop simulating the session and drive a real Chrome instead. Thu, 28 May 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/capture-trace-spa-shells.html https://taprun.dev/blog/capture-trace-spa-shells.html An audit of Tap's recent capture traces found that 34% were retry loops against single-page-app shells — same URL, three to five attempts, identical 200-OK empty bodies. Two ADRs and five commits later, the first-time success rate stopped depending on luck. Fri, 22 May 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/scrape-behind-login-walls.html https://taprun.dev/blog/scrape-behind-login-walls.html r/webscraping keeps asking the same architectural question — how to scrape past OTP, CAPTCHA, Cloudflare Turnstile, Incapsula. The cheapest answer is to stop fighting detection and use your real authenticated browser instead. Sat, 16 May 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/playwright-mcp-named-sessions-engineering-notes.html https://taprun.dev/blog/playwright-mcp-named-sessions-engineering-notes.html A feature request to add named, persistent BrowserContexts to playwright-mcp surfaces a deeper problem: once sessions are first-class objects, the manifest describing them needs a stable schema before it grows a long tail of consumers. Tue, 28 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/taprun-executor-0-8-ms-library.html https://taprun.dev/blog/taprun-executor-0-8-ms-library.html Tap spent three months as a compiled binary that every embedding product had to shell out to. We extracted the composition engine into @taprun/executor — a Deno-first, zero-dep, 65KB package that runs pipes in-process. Measured against the old subprocess path on the same pipeline: 0.8 ms vs 233.7 ms. 294× faster, zero semantic change, full backwards compatibility. Here's why the extraction matters for every product that wraps an LLM. Sat, 11 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/tap-trace-found-the-bug-in-our-reference-pipe.html https://taprun.dev/blog/tap-trace-found-the-bug-in-our-reference-pipe.html We shipped tap.explain, forge.pipe, and tap.trace in one session. The first real demo composed a pipe in Claude Code, saved it, ran it against live Reddit, failed, and iterated through four rounds to a working version — every fix driven by a specific piece of trace data, every round still zero external AI cost. Along the way we found the same silent bug sitting in our hand-written reference pipe. Sat, 11 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/rdk-compiled-pipes-from-llm-prompts.html https://taprun.dev/blog/rdk-compiled-pipes-from-llm-prompts.html Reddit Demand Kit's market_scan tool burns 26,000 LLM tokens every time a user runs it — $0.15 per call, $135/month for a heavy user. We compiled the prompt into a deterministic JavaScript pipeline that produces the same structured output with zero LLM tokens per run. Break-even: 0.46 of a single invocation. Here's how we did it with Tap's new composition DSL, and why every LLM-wrapping product should steal this pattern. Sat, 11 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/composable-taps-are-just-javascript.html https://taprun.dev/blog/composable-taps-are-just-javascript.html GitHub Actions pipelines are YAML. Kubernetes is YAML. CircleCI, Airflow, n8n — all YAML. When we designed Tap's composition DSL, the convention was obvious. We picked JavaScript instead, and it's strictly better for every argument YAML is usually chosen for: diff-friendly, AI-generatable, type-checked, debuggable. Here's the full breakdown with real before/after code from migrating Tap's bounty/match composite tap. Sat, 11 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting) https://taprun.dev/blog/building-mv3-extension-git-log-retrospective.html https://taprun.dev/blog/building-mv3-extension-git-log-retrospective.html Building Tap's Chrome extension meant fighting Chrome MV3 for three months — service worker termination, chrome.alarms' silent 1-minute floor, the 25-second timeout cap, chrome.storage.session as the only durable state, the CDP debugger-attached bar, the unsafe-eval ban, and tab stealing across sessions. A category-by-category tour of forty-ish real commits that got Tap to ship. Sat, 11 Apr 2026 00:00:00 +0000 noreply@taprun.dev (Leon Ting)