| name | youtube-ab-tester |
| description | End-to-end YouTube A/B testing for Ray's channel (@RAmjad) — title generation via subagent, thumbnail image generation via `gemini-3-pro-image-preview` at 1K, results recording, and the underlying scripts/golden references all live here. Use whenever the user wants to brainstorm titles, generate thumbnails (text or images), record A/B test results, analyze title/thumbnail performance, or asks things like "suggest titles", "what titles should I test", "make a thumbnail", "thumbnail variations", "5 thumbnails for this video", "Matt style", "Nate style", "record these results", "what's working", or "update the A/B test results". Also trigger when the user shares a screenshot of YouTube A/B test results and wants analysis or recording. Do NOT use for competitor title research (the youtube-outlier-research routine covers niche/competitor research) or video scripting (use youtube-scriptwriter instead). |
What This Skill Does
End-to-end YouTube A/B testing — titles, thumbnails (text AND images), results recording, all under one roof.
Two main modes:
- Pairing mode (title + thumbnail concepts) — user asks for titles or pairings. Spawn a subagent, get back a pre-paired slate.
- Image generation mode — user asks for actual thumbnail images. Use
scripts/generate.ts (Gemini) with face references and Matt or Nate golden refs.
Plus results recording, manifest tracking, and cross-video pattern analysis — these stay in main context.
Hard rule: title generation is ALWAYS delegated to a subagent. Never brainstorm titles in main context — the reference data is heavy (master-summary + anti-patterns + 4-6 recent video files + the transcript) and synthesizing it inline pollutes the conversation. See "Title generation: always delegate to a subagent" below.
What stays in main context:
- Framing the user's ask, spawning the subagent, presenting the slate
- Recording A/B results (mechanical file work)
- Analyzing CTR/watch-share screenshots
- Firing
scripts/generate.ts with Ray's chosen pairings
- Cross-video pattern discussion
Folder layout of this skill
youtube-ab-tester/
├── SKILL.md ← this file
├── .env ← GEMINI_API_KEY lives here
├── package.json, tsconfig.json, node_modules/
├── scripts/generate.ts ← image generation (gemini-3-pro-image-preview at 1K)
├── app.py, compare.html ← Streamlit lab for browsing thumbnails
├── feedback.json ← global feedback rules + per-thumbnail comments
├── golden-references/ ← image references for Matt and Nate styles
│ ├── matt-style/
│ └── nate-style/
└── references/
├── matt-style.md ← Matt-style layout rules
├── nate-style.md ← Nate-style layout rules
├── thumbnail-analysis.md
├── rays-face/ ← face reference for image generation
├── results/ ← per-video A/B test results (YYYY-MM/ folders)
└── thumbnails/ ← generated thumbnails (v{N}-{slug}/ folders)
Before you do anything: read the reference data
The reference data is the source of truth — re-derive recommendations from actual test results each time, not from baked-in formulas.
references/results/_overview.md — START HERE. The routing map: which doc owns which question, the read-order map, and the authoritative video index (# → date → file, including the V27/V30 numbering note). Open this first whenever you're unsure where a fact lives.references/results/_master-summary.md — Winning patterns, formula rankings, key rules, division of labor, test mechanics, diagnosis logic. Opens with a Durable Insights TL;DR.references/results/_anti-patterns.md — The avoidance rules (never-do + downgraded). Single source of truth for what NOT to do.references/results/_tests-still-worth-running.md — Untested hypotheses worth exploringreferences/results/YYYY-MM/ — Per-video A/B test results, YYYY-MM-DD-slug.md. Read the most recent 4-6 video files (glob the latest month folder) for current patterns.references/thumbnails/v{N}-{slug}/tested/ — winning thumbnails by video, browse to see what worked- Cross-skill input: the latest 2-3 posts in the #yt-outlier Slack channel (read via the Slack MCP
slack_read_channel) — what's winning across the niche right now, produced by the routines/youtube-outlier-research.md scout routine. The A/B archive says what worked for Ray; the #yt-outlier posts say what's working in the niche this week. Title generation reads BOTH (the subagent template below requires it).
This file (SKILL.md) holds operating procedure only. Patterns and rules live in the results/ docs above — SKILL.md points to them and must not restate them (a restated rule drifts out of sync on the next edit).
Recency Weighting
Audience preferences drift over time. When patterns from older videos conflict with newer ones, trust the newer data:
- Last ~4 videos: Full weight — reflects current audience behavior
- 5-9 videos ago: High weight — verify against recent results
- 10+ videos ago: Reduced weight — foundational anti-patterns are durable, but specific scores drift
Durable (structural, survive across videos) vs trend-sensitive (re-evaluate when newer data contradicts): the classification and the full evidence live in _anti-patterns.md (durable never-dos + the Downgraded judgment-calls section) and _master-summary.md § Key Rules. Don't restate them here — read those. Rule of thumb: structural anti-patterns (mechanism-description titles, pipe format, "Stop X", "Explained", multiple features) are durable; verb rankings, whether "Anthropic" is required, title length, and which curiosity frames resonate are trend-sensitive.
PART 1 — Title generation (always via subagent)
Never write titles in main context. Title brainstorming requires reading the full reference corpus (master-summary, anti-patterns, 4-6 recent video files, the 2-3 latest #yt-outlier Slack posts, the transcript or topic brief, and socials/youtube/videos/uploaded/ for stale-template checks). Doing this inline burns main-context tokens and pollutes the conversation.
Instead: spawn a fresh general-purpose subagent with a self-contained prompt. The subagent reads the data, synthesizes the slate, and returns title + thumbnail pairings as one structured output.
How to dispatch
Use the Agent tool with subagent_type: "general-purpose". Pass the full briefing in the prompt — the subagent has zero conversation history.
Template prompt:
You are generating a YouTube A/B test slate for Ray's channel (@RAmjad). You will produce TITLE + THUMBNAIL PAIRINGS — not two separate lists.
# Video context
Topic: <one-line summary>
Transcript: <inline OR path to file>
# Required reading (read all before generating)
1. /Users/ray/Desktop/ray-os/.claude/skills/youtube-ab-tester/references/results/_master-summary.md
2. /Users/ray/Desktop/ray-os/.claude/skills/youtube-ab-tester/references/results/_anti-patterns.md
3. /Users/ray/Desktop/ray-os/.claude/skills/youtube-ab-tester/references/results/_tests-still-worth-running.md
4. The 4-6 most recent video result files under references/results/YYYY-MM/ (latest month first)
5. The 2-3 most recent posts in the #yt-outlier Slack channel — what's winning across the niche RIGHT NOW, plus any shell-fatigue warnings about Ray's own title patterns. Read them via the Slack MCP: load the tool first with ToolSearch (`select:mcp__claude_ai_Slack__slack_read_channel`), then read the newest messages from the `yt-outlier` channel. If the channel can't be read or the newest post is >14 days old, say so instead of inventing niche signals.
6. socials/youtube/videos/uploaded/ — list filenames to check 60-day template reuse
7. Optionally browse references/thumbnails/v{N}-{slug}/tested/ folders from recent videos to see what winning thumbnails looked like
# Hard rules
- Apply recency weighting (last 4 videos full weight; 5-9 ago high; 10+ durable anti-patterns only).
- Ground at least 2 options in a CURRENT outlier signal from the #yt-outlier posts. Cite the actual outlier title + channel + multiplier inline. Only cite patterns that literally appear in a post — never stretch an outlier to fit a frame you already wanted (e.g. do not relabel an urgency-listicle outlier as evidence for a momentum frame). If no recent post exists (>14 days old), say so instead of inventing signals.
- Heed shell-fatigue warnings from the #yt-outlier posts (e.g. an overused opener shell across Ray's recent uploads) even when that shell is PROVEN in the A/B archive — flag any option that reuses a fatigued shell.
- Flag template reuse from the last 60 days. Justify any reuse in writing.
- Frame diversity: at least 3 genuinely different framing categories.
- Title + thumbnail must be COMPLEMENTARY, not redundant. Title says WHY/WHO, thumbnail says WHAT.
- Ceiling warnings — TWO distinct effects (see `_anti-patterns.md` § Ceiling Anti-Patterns): (a) FORMAT: thesis/paradigm/leak/pillar videos historically pull ~17K vs ~45K for single-feature (pillar exception: 5x masterclass CTR); (b) TOPIC: non-Anthropic topics (e.g. Codex) cap views even in feature format and compound on consecutive off-topic videos.
- Anti-patterns: apply the FULL `_anti-patterns.md` table (required reading #2 above) — it is the single source of truth and includes the Downgraded/weak-negative section. Do not work from memory. Worst offenders to never ship (quick safety net): literal mechanism-description titles, absence-negation/passive-evidence framing ("Hasn't Announced", "The Signs Say"), "Stop X" accusatory, "Explained" framing, pipe format, multiple features in title, secrecy words and bare "(Leak!)" tags, topic-mismatched verbatim reuse.
# Output format
## Ceiling warning (format or topic)
<only if applicable. Skip otherwise.>
## R1 recommended trio (3 frame-diverse pairings)
For each:
- Title: "..."
- Frame: <authority | observable social proof | concrete-proof | pillar/insider | concrete-mechanic | rivalry/benefit-equivalence>
- Evidence: <channel A/B precedent and/or current outlier signal (title, channel, multiplier)>
- Thumbnail concept: <Matt-structural | Nate-folder | hybrid>
- Thumbnail text: "..." (2-3 words ideal)
- Complementarity check: <one line>
- Risk flags: <stale template / fatigued shell / topic ceiling / anti-pattern adjacent>
## Extras (5-7 more options)
Same format. Cover authority, social-proof, concrete-proof, insider/pillar, concrete-mechanic.
## Hard rules for THIS video
3-5 bullets: stale templates to avoid, frames to NOT reuse, format-specific cautions.
# Required: be terse. Numbered lists, not paragraphs. Pairings, not separate sections.
When the subagent returns, present the slate to Ray as-is (do not re-narrate). Help him pick the R1 trio if he asks, and write the manifest when he commits.
Why a fresh subagent (not a fork)
- Reference data load (~6-10 file reads) is heavy and one-shot — clean context handles it best
- Title synthesis is closed-task with a clear output spec — no conversation state needed
- Main context stays clean for the pairing-selection conversation that follows
PART 2 — Thumbnail image generation
When Ray asks for actual thumbnail images (not just text concepts), use scripts/generate.ts. This was formerly the youtube-thumbnail-generator skill — same scripts, now consolidated here.
The two style systems
Before generating, commit to ONE style per batch — never mix.
| Style | Feels like | When to use |
|---|
| Matt Pocock | Well-designed explainer slide | Features, comparisons, how-it-works, announcements, teaching |
| Nate Herk | Big folder / app-icon studio shot with a slash command | New command/tool launches, integration videos, "I built X" |
Each has a golden reference library under golden-references/matt-style/ or golden-references/nate-style/, and its own rules:
- Matt style → read
references/matt-style.md
- Nate style → read
references/nate-style.md
Standard workflow
- Determine video slug + folder. Target folder is
references/thumbnails/v{N}-{slug}/ (for tested videos) or references/thumbnails/pending-{slug}/ (for untested). Create if missing.
- Confirm style (Matt or Nate) with the user if not clear from context.
- Get the content — transcript or script/description.
- Read the style's reference file (
references/matt-style.md or references/nate-style.md).
- Read
feedback.json for global feedback rules (facial expressions, hairstyle, outfit).
- Write 5 prompts by hand, each using a different golden reference. Never use subagents for prompt writing — they lose visual context.
- Fire 5 generations in parallel with
run_in_background: true. Use --name to save directly to the target folder.
- Wait via Monitor tool watching the target folder for the final count.
- Open the folder when done.
Generate command
cd .claude/skills/youtube-ab-tester && npx ts-node scripts/generate.ts "<prompt>" \
-n 1 -o "references/thumbnails/v{N}-{slug}" \
--name "<style-prefix>-<concept>-<variant>" \
-r "golden-references/<style>/<golden-ref>.png" \
-t 240
Options:
-n, --count — Number of images (use -n 1 for thumbnails — always)-o, --output — Output directory-t, --timeout — Timeout per image in seconds (always use 240)-r, --reference — Single golden reference image (use ONE per generation — multiple wash styles into a generic average)--no-face — Skip face references (faceless is composition-dependent, not banned — faceless won V20 thumb R1 and V17 R2; use for deliberate faceless test arms)--text — Text with stronger spelling emphasis--name — Output filename without .png extension; saves as <output>/<name>.png--clone — Clone mode: pass an existing thumbnail to recreate with different text. Requires --text.
Why 5 variants, not 20
The explore phase (mapping the design space) is done — the golden libraries ARE the explore output. For a new video, generate 5 well-targeted variants using 5 different golden references. If the user wants more, generate another 5.
Clone mode
Same composition, different text:
cd .claude/skills/youtube-ab-tester && npx ts-node scripts/generate.ts \
--clone "references/thumbnails/v18-ultraplan/folder-ultraplan-golden-ref.jpeg" \
--text "/ultrareview" \
--name "folder-ultrareview-contemplative" \
-n 1 -o "references/thumbnails/v19-ultrareview"
Use clone mode when: same as X with different text, variant of an existing thumbnail for a new video, generating a series with consistent style.
Don't use clone mode when the user wants different composition, expression, or layout.
Hard rules (image generation)
Subject:
- Ray = young South Asian man, glasses, naturally straight dark hair (NOT curly, NOT wavy)
- Outfit: black t-shirt OR plain white collared long-sleeve shirt — nothing else
- Expression: warm genuine smile, knowing smirk, or contemplative — NEVER shock, surprise, or exaggerated reactions
- Shure SM7B podcast microphone rising from the bottom-right foreground (when composition has room)
Face reference:
- Default:
references/rays-face/go-to-face.png — transparent-background head-and-shoulders. Resolution: gemini-3-pro-image-preview-friendly, no extraction step required.
- Fallback:
references/rays-face/go-to-face.jpg (legacy, opaque). The script auto-prefers the PNG if both exist.
- Always used, always alone. Script loads it automatically; no isolation step needed.
Face composition (Nate-style):
- The transparent background lets the generator place Ray's head ANYWHERE in the frame — exploit this.
- Default position: bottom-right or right-of-center, with the subject of the thumbnail (folder, terminal, diagram, slash command) occupying the left two-thirds of the canvas. This mirrors Nate Herk's winning compositions (v16 dream-folder 34.9%, v17 leak-folder 35.5%).
- Face should be 3/4-frontal or slightly turned toward the subject so the eyeline directs the viewer to the visual element.
- Crop tightly: head + shoulders only. No empty headroom above the hair.
- The transparent PNG means the model can match face lighting/edges to any background — black, white, gradient, terminal-screen blue, folder-icon yellow. Specify the background explicitly in the prompt.
- When the composition needs the subject centered (rare — usually announcement/news only), use a smaller face inset in the bottom-right corner instead of dropping the face entirely.
Generation mechanics:
-n 1 per run (never -n 2)- One golden reference per generation
- Up to 5 parallel
Bash calls with run_in_background: true
-t 240 (4-minute timeout) on every call--name to save directly to final folder — no temp dirs
Never do:
- Subagents for prompt writing (they lose visual context)
- Multiple competitor references in one generation
- Metaphor illustrations (cameras, bells, zzz clouds, cartoons) — failed in testing
- Giant single-word typography as the only element — failed in testing
- Crossed-out / X-marked commands — Ray rejected these
- Defaulting to faceless without a reason — face remains the default, but a strong faceless concept is a legitimate test arm (faceless won V20 thumb R1 at 38.5% auto-declared and V17 R2; lost V13/V22/V25)
Golden references (current set)
golden-references/
├── matt-style/
│ ├── ray-command-list-v1-37pct.png ← original command list (37.2% R1 peak)
│ ├── ray-command-list-v2-40pct.png ← ✅ BEST: subtly impressed white oxford, 40.3% R2 peak
│ ├── winner-v20-advisor-command-list-41pct.png ← v20 R1 1st: command-list excalidraw (41.1%)
│ ├── winner-v18-plan-mode-icons-39pct.png ← v18 R1 1st: plan-mode 2-icon (38.5%)
│ ├── winner-v20-advisor-before-after-37pct.png ← v20 R2 1st: before/after (37.2%)
│ ├── winner-v21-monitor-slash-list-36pct.png ← v21 R1 1st: slash-list top structural (36.2%)
│ ├── winner-v15-shift-dark-icons-34pct.png ← v15 1st tied: dark-icon shift (34.3%)
│ ├── winner-v15-github-future-of-coding-34pct.png ← v15 1st tied: github-card mockup (33.9%)
│ └── liked-examples/ ← Ray's eye-picked compositions
└── nate-style/
├── winner-v16-auto-dream-folder-35pct.png ← v16 R1 1st: dream-folder (34.9%)
├── winner-v17-leak-folder-serious-36pct.jpg ← v17 R1 1st: leak-folder serious (35.5%)
└── folder-command/
├── folder-command.png ← contemplative medium shot
└── folder-command-closeup.jpeg ← close-up face crop
When Ray marks a new generation as a winner, save it into the appropriate style folder so future sessions benefit.
Regenerate from feedback
When the user says "regenerate from feedback":
- Read
feedback.json
- Find all thumbnails with non-empty comments
- For each, construct a new prompt keeping what Ray liked and fixing what he didn't
- Apply all
global_feedback rules
- Generate into the video's folder with
-v2 suffix
Feedback system
feedback.json is the single source of truth for user preferences. Before every generation run:
- Read
feedback.json
- Apply all
global_feedback rules to every prompt
- Check
preferred_style for the default if not specified
- If regenerating from comments, incorporate per-thumbnail feedback
YouTube Lab (Streamlit app)
cd .claude/skills/youtube-ab-tester && streamlit run app.py --server.port 8503
open http://localhost:8503
Three pages: Dashboard (all videos), Review (shortlist per video), Results (A/B test outcomes). Data in lab/data.json.
Image generation settings
- Model:
gemini-3-pro-image-preview (set via MODEL_NAME in scripts/generate.ts)
- Resolution: 1K (set via
imageSize: "1K" in scripts/generate.ts)
- Aspect ratio: 16:9 (YouTube standard)
- Timeout: 240s per image (
-t 240)
- Parallel cap: up to 5 concurrent generation processes
- Auth:
GEMINI_API_KEY in this skill's .env or project root .env
PART 3 — Tracking, recording, diagnosis
Tracking uploaded variants (write the manifest BEFORE the test runs)
Every video's thumbnail folder lives at references/thumbnails/v{N}-{slug}/. That folder holds the full generated pool at the top level. A single file, uploaded.json, pins which of those files are actually live on YouTube for the current A/B test.
When to write the manifest: the moment Ray says "testing these three", "uploading X/Y/Z", or otherwise commits a set to a live YouTube test. Write it BEFORE the test runs.
Format — references/thumbnails/v{N}-{slug}/uploaded.json:
{
"video_id": "EhiJX0WvRz4",
"video_title": "Anthropic's New Ultrareview Is Coming: What You Need to Know",
"uploaded_at": "YYYY-MM-DD",
"round": 2,
"variants": [
"matt-structural-three-modes-b.png",
"matt-comparative-before-after-d.png",
"plan-mode-2-faceless-icons-v2.png"
]
}
Rules:
- Every filename in
variants MUST exist at the top level of the same folder. If Ray names a file that isn't there, stop and ask.
- If a new round of the same test starts, bump
round and overwrite. The ranked copies from the previous round already live in tested/.
- The manifest is the single source of truth for "what's live right now."
Recording A/B Test Results
IMPORTANT: Record results immediately. As soon as the user shares A/B test results, record them to the reference files BEFORE suggesting the next round.
When the user shares A/B test screenshots or results:
- Read
references/thumbnails/v{N}-{slug}/uploaded.json first. It tells you exactly which files are live. Never guess from the full pool.
- Match each file in
variants to its rank and pct from the screenshot.
- Copy (don't move — keep originals in the pool) each tested file into
references/thumbnails/v{N}-{slug}/tested/ as {rank}-{pct}pct-{original-stem}.{ext}.
- Record results in
references/results/YYYY-MM/YYYY-MM-DD-slug.md with the markdown table format. Round header: ### Title A/B Test Round N (YYYY-MM-DD). For a brand-new video, create the month folder if needed.
- Write "Key takeaways" referencing specific data points from previous videos.
- End with a clear recommendation for the next round.
Folder layout (results archive)
references/thumbnails/v{N}-{slug}/
uploaded.json # manifest — what's currently live
tested/ # ranked copies of completed rounds
1st-38.5pct-<original-stem>.png
2nd-35.3pct-<original-stem>.png
3rd-26.2pct-<original-stem>.png
<all generated variants>.png # the full pool
Diagnosing Bottlenecks
When results are flat across title variants:
- All titles share the same frame → the frame is the problem, test different frames
- Titles use diverse frames but all score ~0-2% spread → thumbnail is the ceiling, switch to thumbnail testing
- A proven winner formula suddenly scores ~33% → something external is capping it (thumbnail mismatch, audience fatigue, topic ceiling)
- Control decay is routine — don't lock after one round, and don't read a small control drop as a problem.
- Within-test share ≠ video success — if YouTube's early-warning fires, the topic/format is the ceiling and more title rounds won't fix it.
(Evidence/citations for control decay and share≠success live in _master-summary.md § Test Mechanics — this is the operational shortcut.)
When to Recommend What
- Title testing first — almost always start here. Titles have wider performance range than thumbnails.
- Switch to thumbnail testing when 3+ diverse title frames produce identical results.
- Consider topic ceiling when both title and thumbnail optimization plateau.
- CTR/impressions problem (not watch-share) — banked from V29/V30: when YouTube flags "fewer subscribers choosing to watch" within ~90 min, recommendations crater. That's a thumbnail or topic problem, not a title problem. Don't keep re-testing titles.
