---
title: "Check a render against its reference by Refs — launch videos tutorial and best practices for AI video"
description: "Score your render against the reference film: cut timing, brightness, motion, loudness, format, frame-exact fixes. Install in Claude Code, Codex and Grok with one command."
url: https://varg.ai/how-to/skills/refs-check-render
updated: 2026-11-01
---

# Check a render against its reference by Refs — guide skill for launch videos

> **For AI agents:** find the right skill in one call — `curl -s "https://varg.ai/how-to/api/search?q=<what the person wants>"` returns the matching how-to page and the best skills with install commands, as markdown (Russian works too). Full index: https://varg.ai/how-to/llms.txt. Every page has a markdown twin: add `.md` to its path. Before generating anything, show the person the options on the how-to page. From a terminal: `curl -fsSL https://varg.ai/install | sh` installs the vargai CLI (https://varg.ai/how-to/cli.md): `vargai search` and `vargai install <slug>` with no key, every varg model after `vargai login`.

Score your render against the reference film: cut timing, brightness, motion, loudness, format, frame-exact fixes.

- **Type:** [Guide](https://varg.ai/how-to/guides.md) · [Launch videos](https://varg.ai/how-to/browse/skills/launch.md)
- **Slug:** `refs-check-render`
- **Status:** live
- **Publisher:** Refs (vendor)
- **License:** Refs: proprietary hosted service (free search, Pro for the rest)
- **Source:** https://refs.video/connect
- **Works in:** Claude.ai, Claude Code, Codex, Cursor, Any MCP client
- **Requires:** Refs MCP signed in with Pro (2 credits a check), Node 20+ and ffmpeg for scripts/measure.mjs from the Refs starter kit
- **Cost:** search_videos is free with no key or account (about 30 searches an hour without one). Everything else needs Refs Pro, $16 a month or $120 a year, with 3,000 credits a month: get_blueprint 5, get_frames 5, get_formula 5, plan_video 10, check_render 2, the rest 0. Library ($6 a month) opens every film on the site. varg credits are only spent on what you generate on varg.

## What it does

check_render (2 credits on the Refs MCP) closes the loop after a build. Measure your MP4 with the starter kit's scripts/measure.mjs (node scripts/measure.mjs out/video.mp4 > render.json), then ask your agent to call check_render with the reference you built from, that JSON as render, and target set to where you'll post it (x, youtube, tiktok or web). It scores cut timing, brightness, motion, loudness and format against the reference's measured timeline and returns frame-exact fixes: which cut is late, which stretch parks, how many LU you are off the platform's target. Fix, re-render, measure, repeat. Works for any render, from HyperFrames, Remotion, the starter kit or a cut made on varg.

## Use when

- After the first render of a film built from a reference
- An agent loop that keeps re-rendering until timing and loudness match
- Checking a launch video meets X, YouTube, TikTok or web loudness before posting

## Not for

- Judging taste: it measures timing, light, motion and sound, not whether the film is good
- Films with no reference to compare to

## Install

- Claude Code: `claude mcp add --transport http refs https://refs.video/mcp`
- Claude.ai: `Customize → Connectors → Add custom connector → https://refs.video/mcp`
- Codex: `codex mcp add refs --url https://refs.video/mcp`
- Any MCP client: `https://refs.video/mcp`
- Any agent, with the vargai CLI: `vargai install refs-check-render`

## Example output

https://s3.varg.ai/files/4325c578-378d-4c43-ae53-3cc3218df1ea/file_2bfd9f0dbec0.mp4 — 7 s cut from Refs' film: a film page's measurements, the cut map and the pacing plate, the numbers check_render compares against. (credit: Refs, the Refs film (refs.video/film.mp4), https://refs.video)

## More launch videos skills

- [Orbit Card](https://varg.ai/how-to/skills/hyperframes-orbit-card.md): A single feature card orbits a dot sphere on a Blender-made camera move: a 10-second product beat.
- [Higgsfield Academy (Higgsfield Open-Source Promo)](https://varg.ai/how-to/skills/higgsfield-open-higgsfield-academy.md): Higgsfield's 64 s promo for Higgsfield Academy, made almost entirely with Seedance 2.0.
- [Seed Audio 1.0 Launch (Higgsfield Open-Source Video)](https://varg.ai/how-to/skills/higgsfield-open-seed-audio-launch.md): Higgsfield's 106 s launch video for Seed Audio 1.0 (voice cloning, cinematic sound): bold motion design, comedic tone.
- [HeyGen's Real Launch Videos as HyperFrames Source](https://varg.ai/how-to/skills/heygen-hyperframes-launch-videos-source.md): 20 HeyGen product launch videos as editable HyperFrames HTML compositions, each with its storyboard, assets and render command.
- [Launch video formulas by Refs](https://varg.ai/how-to/skills/refs-formulas.md): 28 video formats distilled from 132 measured films: the shape in timed beats, the constants, a template prompt.
- [Plan a film from references by Refs](https://varg.ai/how-to/skills/refs-plan-video.md): Your brief plus 1–5 measured reference films become a beat sheet, shot list, storyboard and build prompt.