create-chatgpt-mockup

Purpose

Generate single-frame ChatGPT mobile screens that read as real iOS captures — accurate header chrome, user/assistant message styling, composer pill, status bar, and the OpenAI spiral mark. Designed for use inside ad creatives, social posts, video storyboards, and product mockups.

If you need an animated, video-recorded chat reveal (bubbles popping over time, SFX, music bed, end card), use the molecule skills/molecules/create-chatgpt-video-ad. This atom only produces a single still frame.

Inputs

Compose a thread.json matching the schema below, then pass it to render.js.

Thread JSON schema

{
  "statusBar": {
    "time": "9:41",
    "dnd": false
  },
  "header": {
    "style": "model-tag",
    "title": "ChatGPT",
    "model": "5.1",
    "rightIcons": ["personPlus", "dottedCircle"]
  },
  "messages": [
    { "type": "user-image", "src": "assets/photo.jpg", "aspect": "square" },
    { "type": "user-text",  "text": "Make this face sunscreen better" },
    {
      "type": "assistant",
      "title": "Optional H1 with spiral logo",
      "feedback": true,
      "text": "Markdown-ish prose. **bold**, *italic*, ## H2, * bullet, 1. ordered, [[cite:Source +1]], [[icon:💡]] inline-icon."
    }
  ],
  "composer": {
    "placeholder": "Ask anything",
    "text": "Typed text to show with caret",
    "cursor": true,
    "streaming": false,
    "chip": { "name": "SeatGeek" }
  }
}

Field reference

statusBar

• time — string shown top-left (e.g. "9:41", "08:18").
• dnd — when true, renders a small moon glyph next to the time (matches iOS Focus-on indicator).

header.style — one of:

• "model-tag" — ≡ ChatGPT 5.1 ▾ ●● — used when a specific model is active.
• "title-only" — ≡ ChatGPT › ●● — the plain in-chat header.
• "plain-title" — ≡ Get Plus ✦ ●● — for the upsell/empty-state title.

header.rightIcons — array of icon keys, rendered left-to-right on the right side. Available: "personPlus", "dottedCircle", "edit", "more". Default is ["personPlus", "dottedCircle"] for model-tag, ["edit"] for title-only.

messages[] — one of:

• { "type": "user-image", "src": <path>, "aspect": "square"? } — relative src paths resolve against the thread.json directory.
• { "type": "user-text", "text": <string> } — right-aligned soft-gray bubble.
• { "type": "assistant", "text": <markdown>, "title"?: <string>, "feedback"?: <bool> } — left-aligned plain prose. If title is set, an OpenAI spiral logo + bold title is rendered above the body. feedback: false hides the thumbs-up/down chips.

Assistant text markdown — supported syntax:

• **bold**, *italic*
• # H1, ## H2, ### H3
• * item / - item bullet lists
• 1. item ordered lists
• --- horizontal rule
• [[cite:Some Source +1]] — pill citation chip
• [[icon:💡]] — inline emoji prefix (kept un-escaped)
• Single \n → soft line break (<br>); double \n\n → new paragraph

composer

• placeholder — shown when text is empty (default "Ask anything").
• text — typed-in text. When present, the send button activates (black bg).
• cursor — whether to render the blinking caret after text (default true).
• streaming — when true, replaces the send arrow with a stop square (matches "response generating" state).
• chip — optional GPT chip in the composer. chip.name is the GPT name. Sets placeholder to "Ask ChatGPT" if you don't override it.

CLI

node render.js --thread examples/01-sunscreen-image.json
node render.js --thread my-thread.json --output ./exports --name nightly

Flags

Flag	Effect
--thread <path>	(required) JSON file matching the schema above
--output <dir>	parent dir for the dated output folder; default ./chatgpt-mockup-exports/
--name <slug>	override the output folder slug

Output

<output>/<YYYY-MM-DD>-<slug>/
  index.html       # standalone HTML (CSS inlined)
  screenshot.png   # 2250 × 4002 PNG (DPR 3, 9:16)
  thread.json      # copy of the input for reproducibility

Workflow

1. Receive a brief or existing thread JSON.
2. If only a brief is given, compose thread.json matching the schema above.
3. Run node render.js --thread <path>.
4. Open the PNG. If anything looks off (header alignment, bubble width, missing icon), edit the JSON or templates/chat.css and re-render.

Setup (one-time)

cd create-chatgpt-mockup
npm install
npx playwright install chromium

Quality checks

• Renders in light mode only (white background, dark text). Dark-mode rendering is out of scope for v1.
• Status bar time and right cluster (signal / wifi / battery) sit at the very top, no clipping under the iOS status-bar safe area.
• Header chrome icons (hamburger / personPlus / dottedCircle / edit / more) all visually weigh the same as a real ChatGPT iOS screenshot at the same display size — eyeball, don't pixel-match. Sub-reading-weight icons read as broken even when their pixel dimensions "match the spec."
• Header model tag (5.1, 5.2) sits inline with ChatGPT and its chevron — no wrapping.
• User bubble is right-aligned, soft-gray (#F4F4F4), border-radius: 28px, max-width 78% of stage.
• User image attachments use the same 28px corner radius and sit right-aligned above the text bubble.
• Assistant body is plain prose (no bubble), left-aligned, full-width within the gutter.
• Composer corner radius is 999px (full pill), 1px border #E5E5E5, send button is 44 × 44 round.
• When composer.text is set: send button is solid black with a white up-arrow. Caret sits right after the last character of typed text.
• When composer.streaming: true: send button shows a black square stop icon.
• When a citation marker [[cite:Foo +1]] is in the assistant text, it renders as a pill chip inline at the end of the sentence.

Failure modes

Symptom	Cause	Fix
Thread file not found	Wrong path or running from a different cwd	Use absolute paths or run from the skill directory
Image attachment shows broken-image glyph	src is relative but the renderer couldn't resolve it	render.js resolves relative src against the thread.json's directory — make sure the asset exists at that path
Send button stays light gray after typing	composer.text is empty string "" instead of unset	Either omit text entirely or set it to a real string
Caret renders as a stray | separated from the text	Caret span is being treated as a flex child	The CSS rule for .composer .input uses inline content flow — do not switch it to display: flex
Streamed list-item words render with no spaces ("Howconversationswork")	.word { display: inline-block } collapses inter-span text-node whitespace inside <div> parents (works fine inside <p>)	Use display: inline for .word — modern browsers honor filter: blur() + opacity transitions on inline elements too
Bullets visible while list-item text is still hidden during streaming	CSS list-style markers are browser-painted; the word-stream wrapper only sees text nodes	The atom auto-converts <ul><li>X</li></ul> to <div class="md-list"><div class="md-li">• X</div></div> when stream: true — keep that pass; don't regress it. Any new markdown that emits browser-painted glyphs (::marker, quotes, counter-content) needs the same text-conversion treatment.
Markdown --- doesn't render an <hr>	The --- line isn't on a line by itself, or the surrounding text didn't end its paragraph	Surround --- with blank lines on both sides
Stanzas of a poem joined into single paragraphs	Lines separated by single \n get joined as a single paragraph but with <br> between them — this is the intended behavior. If you want stanza breaks, use \n\n between stanzas.
Header right cluster overlaps the model tag on long titles	Title text is too wide for the centered slot	Shorten header.title, drop the model tag, or switch header.style to "title-only"

Files

File	Purpose
render.js	CLI entry — parses flags, generates HTML, takes screenshot, writes outputs
generate.js	Thread JSON → standalone HTML page (markdown-ish parser inside)
screenshot.js	HTML → PNG via Playwright (chromium headless) at fixed 750×1334 / DPR 3
templates/chat.css	All visual styling
templates/icons.js	Inline SVG icons (hamburger, chevrons, spiral logo, mic, plus, send arrow, stop square, signal/wifi/battery, thumbs up/down)
examples/*.json	6 reference threads exercising every variant
examples/assets/	Placeholder image assets used by image examples
tests/run-all.sh	Render every example into tests/output/ for visual review

Known limitations

• Light mode only. Dark mode would require a separate theme block and is out of scope for v1.
• No carousel / horizontal-scroll cards. The Apps-SDK SeatGeek reference shows a horizontal card carousel inside the assistant response; not modeled here.
• No live keyboard rendering. The composer is the bottom pill only — no on-screen keyboard chrome, suggestion bar, or QWERTY grid. (If you need the keyboard, scale the screen down 50% and overlay a separate keyboard image.)
• Markdown is intentionally minimal — no tables, no fenced code blocks with syntax highlighting, no nested lists. Add to generate.js#renderMarkdown if a brief requires more.
• Emoji rendering depends on system fonts. Chromium on macOS ships Apple Color Emoji; on Linux ships Noto Color Emoji.

Quality Checks

Run bash tests/run-all.sh and open the PNGs in tests/output/, then confirm:

• Every example renders without error. All six examples/*.json produce an index.html + screenshot.png + thread.json triplet; render.js exits 0.
• Dimensions are stable. Each screenshot.png is 2250 × 4872 (the .stage is 750 × 1624 and screenshot.js captures at deviceScaleFactor: 3). A wrong size means the stage box or DPR changed.
• Light mode, white background. Background is white, text near-black. This atom does not render dark mode.
• Status bar. Time sits top-left; the signal / wifi / battery cluster sits top-right, unclipped. When statusBar.dnd: true (see 02-sleep-apnea-long.json, 05-seatgeek-gpt-chip.json) a moon glyph renders next to the time.
• Header style matches the JSON. model-tag shows ChatGPT 5.1 ▾ (01-sunscreen-image.json, 06-short-howto.json); title-only shows the plain title + right chevron (02, 03, 05); plain-title shows the upsell title with no chevron (04-empty-typing.json). The center cluster never wraps and the right icons never overlap it.
• User turns. User text is a right-aligned soft-gray bubble (#F4F4F4, 28px radius). A user-image (see 01-sunscreen-image.json) renders the attachment right-aligned, same 28px corners, above the text bubble.
• Assistant turns. Assistant prose is left-aligned plain text with no bubble. Markdown renders: bold/italic, ## headings, bullet and ordered lists (06-short-howto.json), --- horizontal rules and the [[cite:…]] pill chip (02-sleep-apnea-long.json), an [[icon:💡]] inline prefix, and title as bold heading text (03-poem-iphone-mac.json, 05-seatgeek-gpt-chip.json). feedback: false hides the thumbs chips.
• Empty state. When messages is empty (04-empty-typing.json) the centered OpenAI spiral hero renders instead of a conversation.
• Composer. Default is the full-pill (999px) bar with +, input, mic, and a round 44×44 send button. With composer.text set (04-empty-typing.json) the send button is solid black and a caret follows the typed text. With streaming: true (02, 03) the send button shows the black stop square. With composer.chip (05-seatgeek-gpt-chip.json) the Apps-SDK GPT chip renders inside the composer above the input row.

Failure Modes

Symptom	Likely cause	What to do
Thread file not found: … then exit 1	--thread path is wrong or the cwd is not the skill dir	Pass an absolute path or cd into the skill directory first (render.js resolves the path against cwd)
Error: playwright not installed	npm install never ran in the skill dir	Run npm install, then npx playwright install chromium (see Setup)
Run hangs ~15s then page.goto … timeout	screenshot.js is waiting on networkidle for an asset that never loads (e.g. a remote/http image src)	Use a local relative src that resolves under the thread.json dir, or an inline SVG asset like examples/assets/sunscreen-sky.svg
Image attachment shows the broken-image glyph	user-image.src is relative but the file is missing on disk	render.js rewrites a relative src to file://<threadDir>/<src>; make sure the asset actually exists there
Send button stays gray after setting text	composer.text is "" (empty string) rather than a real value	Set composer.text to a non-empty string, or omit it to keep the placeholder state
PNG comes out the wrong size	.stage width/height in templates/chat.css or DEVICE_SCALE/VIEWPORT in screenshot.js was changed	Keep .stage at 750 × 1624 and deviceScaleFactor at 3 so output stays 2250 × 4872
Header right icons overlap the model tag on a long title	header.title is too wide for the centered slot	Shorten the title, drop the model tag, or switch header.style to "title-only"
[[cite:…]] or [[icon:…]] prints literally instead of rendering	The marker is mistyped (missing double brackets / colon)	Match the exact [[cite:Source +1]] / [[icon:💡]] form parsed by formatInline in generate.js
Markdown --- shows as text, not an <hr>	The --- line is not on its own line between blank lines	Put a blank line above and below the ---, as in 02-sleep-apnea-long.json