Build log · 4–26 Oct 2026 · from git

First commit to production in 16 days

In 23 days MirrorCut shipped a timeline editor, a 4K render pipeline, an agent that edits from chat, billing, a Mac app and the public launch. Every feature below is in the order it shipped, with how it's built, straight from the git history.

first commit to production
16 days
features shipped
35
commits
840
commits a day, every day
36.5
lines of code
160k
test files
307
apps and shared packages
4 + 9
commits on the busiest day
90

Every feature, in order

What shipped, the day it started, and the technology underneath.

    • Editor· to 5 Oct

      The editor and the Edit Plan

      A timeline editor where every edit, by hand or by the agent, is one reviewable change.

      • The whole edit is one typed document, the Edit Plan, shared by the web app, the API and the Python worker
      • Changes are version-checked changesets, so two writers never overwrite each other
      • Autosave, undo and redo on the same changesets

      TurborepoTypeScriptZodNext.jsZustand

    • Billing

      Accounts

      Sign-up, log-in and settings from the first day.

      • Email and password auth with sessions
      • Profile and password change in Settings

      Better AuthPostgresPrisma

    • Web + SEO· to 5 Oct

      Landing page

      A prompt-first homepage with live example cards.

      • Hero motion drawn procedurally, no stock footage
      • Shared type scale and buttons across the site and auth pages

      Next.jsTailwind CSS

    • Media + render

      Uploads and the media pipeline

      Upload a recording and it plays in the editor within moments.

      • Multipart uploads straight to S3, probed on completion
      • Proxy, poster and waveform jobs on a Redis queue, their lifecycle kept in Postgres
      • Transcription with word timings, so the agent can cut on words

      S3BullMQRedisffmpegAssemblyAI

    • AI agents

      Model router and Mice, the agent

      One agent, Mice, that edits from chat and asks before it spends.

      • A model registry and router with fallbacks, a call log and admin controls
      • Versioned system prompts with output schemas and injection-safe rendering
      • ask_user and confirm_generation enforced by the server, with a cost estimate first

      OpenRouterNestJSZod

    • Media + render

      Motion engine and 4K export

      Designed graphics that look the same in the preview and the export, up to 4K.

      • One scene renderer runs in the browser and on the server
      • Decode, draw and encode overlap on worker threads; hardware H.264 chosen by a test encode
      • A 22-second 4K export went from 129 s to 40 s; sound normalised to -14 LUFS

      @napi-rs/canvasffmpegVideoToolbox / NVENCMediabunny

    • AI agents

      Intent, research and design agents

      Mice understands the request, researches current editing style and calls a motion design team.

      • An intent agent reads the request before anything is edited
      • A research agent brings back live sources
      • A motion critic watches the real rendered motion and asks for one revision

      ClaudeGPTGemini

    • AI agents

      Auto-Edit and stock B-roll

      An AI rough cut that follows the script and the emotion, with licensed B-roll.

      • The planner reads every take as numbered words and returns the cut as word ranges
      • Code checks the plan, paces silences by emotion and keeps the beats
      • Scored 99/100 on the test cut against 50 for the plain agent, about $0.10 a run

      Claude OpusWikimedia CommonsNASA

    • Editor

      Graphics library

      200 templates: lower thirds, titles, stats, quotes, charts, social and end cards.

      • Shipped in four drops in one day
      • Every template is data for the motion engine, so it restyles to the video's fonts and colours

      graphics-kitmotion-engine

    • AI agents

      Colour, looks and guided editing

      Mice balances every camera and offers a look, then guides each video type step by step.

      • HDR and log footage handled, brand-safe looks
      • Cuts land on the music's beats
      • Playbooks per video category

      ffmpeg

    • Billing

      Plans and checkout

      Paid plans with an in-app checkout.

      • A plan is required before the app
      • Checkout in a dialog, webhooks settle the subscription

      Stripe

    • AI agents· to 10 Oct

      The Director and house style

      A Director that assembles the whole video, critiques it and reports what it did.

      • Assemble, critique, report, measure
      • A music bed set from measured loudness, speaker cut-outs reused across runs
      • House type, 100 colour schemes and reference graphics

      ONNX RuntimeClaude

    • Media + render

      Mac app

      A native Mac window onto the web app, so every web deploy reaches it with no release.

      • Window locked to the web origin, a typed and versioned bridge
      • Native saving, notifications, uploads kept alive and a local media cache

      Electronelectron-updater

    • Editor

      Exports you can trust

      Progress you can see, cancel that really stops, and retry for anything that fails.

      • No media job waits forever
      • A cancelled export stops its worker
      • Originals fetched once and cached

      BullMQ

    • AI agents· to 12 Oct

      Reference library and layout rules

      Videos styled from a library of reference grammars, with text that never covers a face.

      • The style card offers three grammars and every worker follows the chosen one
      • Stock cutaways matched to what is said, icons as the fallback
      • A graphic that can't clear a face moves beside the speaker

      Face detectionStock search

    • Launch + ops· to 14 Oct

      CI and deploys

      Every change goes through checks and a smoke test before deploy.

      • Lint, types and tests on every pull request
      • Image artifacts cleaned up after each run

      GitHub ActionsDocker

    • Editor

      New editor layout and the Design panel

      An icon rail with one panel at a time, Mice in its own column, and the video's fonts and colours by hand.

      • Brand fonts in the editor, the type and the export
      • 1,918 open-licence Google Fonts to browse and add
      • Redo saves with a fresh changeset id

      Reactfontkit

    • Media + render

      HTML render service

      Scenes written in HTML become clips on the timeline.

      • A headless render service turns HTML scenes into video
      • The designer can write HTML, and both kinds of scene compete for a hero moment

      HyperFramesGSAPthree.js

    • Billing· to 14 Oct

      Trial, email and the Studio plan

      A free trial, transactional email, verified accounts and three plans.

      • Trial paywall, sign-up and rate limits
      • Email verification required
      • Studio above Pro

      ResendStripe

    • AI agents

      Generated shots and explainer Shorts

      When stock can't show it, Mice generates the shot, and Shorts are cut at a pro editor's rhythm.

      • A still in the video's look, then animated and checked like stock
      • Only after the creator agrees on the storyboard card
      • Prices set so generated video keeps its margin

      Gemini Flash ImageHiggsfield

    • Web + SEO· to 16 Oct

      SEO foundation

      The site goes on Google with honest pricing and comparison pages.

      • Audit fixes: accurate claims, self-hosted fonts, a static homepage
      • Search Console verified
      • Pricing built from the real plan catalogue, comparisons checked against competitors' own pages

      Next.jsschema.orgSearch Console

    • Launch + ops

      HTTPS hardening

      HSTS on the web server.

      • One-year HSTS

      Caddy

    • Web + SEO· to 18 Oct

      Speed and accessibility

      A faster homepage and an accessibility score of 100.

      • Heavy modules kept out of the first JavaScript, the hero paints at once
      • Analytics loaded after the page
      • Contrast and link names fixed

      Lighthouse

    • Media + render

      Voice cleaning

      Cleaner speech from any microphone.

      • Audio filters in the preview and the export

      ffmpeg

    • Launch + ops

      Directory submission kit

      Listing copy, pricing, links and screenshots ready for directories.

      • One source of brand facts for every listing

      Docs

    • AI agents

      Brand ads

      Mice makes a designed ad for any brand from its website, logo or product screens.

      • Ads arrive as editable scenes on the timeline
      • A sound for each kind of moment, on its frame
      • A failed ad gives the credits back

      Puppeteermotion-engine

    • Launch + ops· to 19 Oct

      Security review and first release

      A full-project review before the first production release.

      • No lost edits, honest refunds, enforced upload sizes, backups
      • Workflows documented, production branch merged

      Code reviewSecurity review

    • Web + SEO· to 21 Oct

      Legal pages and answer-engine SEO

      Terms, privacy and child safety published, and every guide answers its question first.

      • A quick answer and a named author on every guide
      • Watch pages for every example ad
      • Comparisons with CapCut and VEED

      schema.orgllms.txt

    • Billing

      Privacy controls

      Delete your account any time, and AI that never trains on your videos.

      • Delete account in Settings with a confirm link
      • AI requests routed only to providers that don't store or train on data
      • 18+ confirmation at sign-up

      OpenRouter

    • Launch + ops· to 21 Oct

      Launch kits

      Product Hunt kit, brand facts and a community reply kit.

      • A local pre-push check that runs what CI runs

      Docs

    • Launch + ops

      Production safety

      Errors reach the team before users report them.

      • Browser errors reported, real error and 404 pages
      • Export concurrency setting, priority renders

      Next.js

    • AI agents· to 24 Oct

      The ad kit

      Ads from a screen recording or straight from the App Store and Google Play.

      • Designer transitions, hook openings and end-card looks
      • Full-screen, 3D device and close-up product scenes
      • 82 reference cards from 100 brands' ads; each ad reads the five nearest

      GSAPiTunes Search APIGoogle Play

    • Web + SEO· to 24 Oct

      Search pages and free tools

      Pages for the searches creators make, and free tools they can use today.

      • Best AI video editors, AI video editor for YouTube, long video to Shorts
      • llms.txt and FAQ kept in step with the product

      Next.js

    • Billing

      Credits and cost tracking

      Every AI call is costed and charged from a credit ledger.

      • Cost tracking per call
      • Refunds settled from the ledger

      Postgres

    • AI agents· to 26 Oct

      Ad scorecard, product and story checks

      Every ad is measured against real product-led ads before anyone sees it.

      • Motion, cuts, contrast, brightness and product share measured against ten real ads
      • A product check so the product is never shown broken: faults went from 14 to 0
      • Story checks before render, three story options and a critic

      MeasurementClaude HaikuHyperFrames

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Source: the git history of the MirrorCut repository, first commit 4 Oct 2026, last updated 26 Oct 2026. 799 of the 840 commits are by co-founder Sagar Dey. Lines of code are tracked TypeScript, JavaScript and Python files; production is the first release to the production branch on 19 Oct. About MirrorCut