chatgen

Generate self-contained HTML mock-ups of chat conversations styled exactly like popular platforms — messengers (iMessage, WhatsApp, Telegram, Instagram DM, Messenger, Signal, Discord, Snapchat, VK, Slack, LINE, X/Twitter DM, WeChat, Viber) and dating apps (Tinder, Bumble, Hinge). Feed it a dialog (participants + messages with timestamps), pick a platform, device, and theme, and get back ready-to-open HTML — or a PNG screenshot.

By default the output is a clean, edge-to-edge screenshot (just the screen, no device bezel). The phone frame is an opt-in.

Install

pip install chatgen          # or:  uv add chatgen

# optional, for PNG export:
pip install "chatgen[screenshots]"
# optional, for MP4/GIF/WebM video export (bundles ffmpeg):
pip install "chatgen[video]"
playwright install chromium

Quickstart

from datetime import datetime
from chatgen import Generator, Dialog, Participant, Message, Text, Image
from chatgen import Platform, DeviceView, Theme, MessageStatus

me  = Participant(id="me",  name="You", is_self=True)
her = Participant(id="her", name="Alex Rivera", subtitle="online")

dialog = Dialog(participants=[me, her], messages=[
    Message(her, datetime(2026, 5, 31, 9, 40), Text("Hey! How's it going? 😊")),
    Message(me,  datetime(2026, 5, 31, 9, 41), Text("Pretty good! You?"),
            status=MessageStatus.READ),
    Message(her, datetime(2026, 5, 31, 9, 42), Image(src="alex_selfie.jpg")),
])

gen = Generator()

# 1) Clean screenshot HTML (default — no device frame)
html = gen.generate(dialog, platform=Platform.WHATSAPP,
                    view=DeviceView.IPHONE_15_PRO, theme=Theme.DARK)
open("chat.html", "w").write(html)

# 2) With the phone bezel (opt-in)
html_framed = gen.generate(dialog, platform=Platform.IMESSAGE,
                           view=DeviceView.IPHONE_15_PRO, theme=Theme.LIGHT,
                           show_frame=True)

# 3) PNG screenshot (needs the 'screenshots' extra)
gen.generate_png(dialog, platform=Platform.TELEGRAM,
                 view=DeviceView.IPHONE_15_PRO, theme=Theme.LIGHT,
                 path="chat.png", scale=2)

API

Generator().generate(dialog, platform, view, theme, **kwargs) -> str       # HTML
Generator().generate_png(dialog, platform, view, theme, *, path=None, scale=2, **kwargs) -> bytes
Generator().generate_video(dialog, platform, view, theme, *, path, fmt=None, # mp4 | gif | webm
                           scale=2, fps=25, animate_delay=600, hold_ms=1400, **kwargs) -> str

Generator().generate_dataset(dialog, platform, view, theme, *, out_dir, name="sample",
                             scale=2, **kwargs) -> dict   # PNG + YOLO labels
Generator().generate_preview(chats, platform, view, theme, **kwargs) -> str  # inbox / chat-list HTML

generate_preview renders the chat-list / inbox screen (not a thread) from a list of ChatPreview rows. Supported on platforms with a standard inbox (WhatsApp, Telegram, iMessage, Instagram, Messenger, Signal, VK, Viber, LINE, WeChat, X/Twitter); others raise.

from chatgen import ChatPreview
chats = [
    ChatPreview(name="Alex Rivera", last="see you then!", time="9:41", unread=2),
    ChatPreview(name="Family", last="📷 Photo", time="Tue", is_group=True, muted=True),
]
html = gen.generate_preview(chats, platform="telegram",
                            view=DeviceView.IPHONE_15_PRO, theme=Theme.DARK)

generate_dataset renders a static PNG and YOLO bounding-box labels — one box per message (classes 0=me, 1=them) plus one box for the contact name (2=name). Boxes come from the real rendered DOM geometry. Writes images/<name>.png, labels/<name>.txt, classes.txt, data.yaml under out_dir (needs the screenshots extra). Supported on bubble platforms + Telegram + Snapchat.

generate_video records the conversation as the messages appear one-by-one (it turns on animate for you) and writes an MP4 / GIF / WebM — format inferred from the path extension. Needs the video extra (Playwright + ffmpeg):

gen.generate_video(dialog, platform=Platform.WHATSAPP, view=DeviceView.IPHONE_15_PRO,
                   theme=Theme.LIGHT, wallpaper="doodle", path="chat.mp4")

• dialog — a Dialog (see model below).
• platform — a Platform enum member or a registry-key string.
• view — a DeviceView: IPHONE_15_PRO, IPHONE_SE, PIXEL_8, ANDROID, WEB.
• theme — Theme.LIGHT or Theme.DARK.

Common kwargs

animate degrades gracefully: with JavaScript disabled or prefers-reduced-motion, all messages show immediately.

Message(reply_to=...) renders an inline reply quote inside the bubble.

Devices (view): iphone_15_pro, iphone_16_pro, iphone_15_pro_max, iphone_se, pixel_8, pixel_9, galaxy_s24, android, web.

Platform-specific kwargs

Data model

Participant(id, name, avatar=None, is_self=False, subtitle=None, age=None, distance=None, bio=None)
Dialog(participants, messages, meta={})
Message(sender, timestamp, content, status=MessageStatus.SENT, reactions=[], reply_to=None)
Reaction(emoji, by)

Content types: Text(body), Image(src, caption), Voice(duration_seconds, transcript), Sticker(src), GIF(src, caption), File(name, size), Location(label, map_image), System(text).

Avatars & images (avatar / src) accept any of: an http(s) URL, a local file path (embedded as a data-URI so the HTML stays self-contained), an existing data: URI, or None (a deterministic initials-on-color placeholder is generated).

Graceful degradation: each platform declares which content types it natively renders; unsupported types fall back to a readable bubble (e.g. Tinder renders a Voice as "🎤 Voice message") instead of breaking.

Supported platforms

from chatgen import list_platforms
list_platforms()
# ['bumble', 'discord', 'hinge', 'imessage', 'instagram', 'line', 'messenger',
#  'signal', 'slack', 'snapchat', 'telegram', 'tinder', 'twitter', 'viber',
#  'vk', 'wechat', 'whatsapp']

from chatgen import list_wallpapers
list_wallpapers()  # 123 named wallpaper themes for the `wallpaper` kwarg
# mood gradients:   sunset, ocean, dusk, forest, rose, midnight, peach, lavender,
#                   mint, graphite, fire, ice, grape, coral, emerald, twilight,
#                   sakura, steel, gold, denim, noir, candy
# Telegram-style:   aurora, tropic, berry, lagoon, blossom, instaglow, seafoam,
# (multi-point      peony, marine, nebula, citrus, orchid, ember, glacier,
#  "freeform")      meadow, rosegold, cobalt
# solid colors:     sand, sage, fog, linen, clay, stone, ink, espresso, mist,
#                   almond, moss, dove, pine, navy, wine, slateblue
# editor/aesthetic: dracula, nord, solarized, solarized_dark, gruvbox, monokai,
#                   catppuccin, tokyonight, onedark, github_dark, vaporwave,
#                   synthwave, matrix, terminal, paper, kraft, chalkboard
# css patterns:     dots, dots_dark, grid, cross, blueprint, carbon, graph, stars
# image patterns:   doodle, polka, hearts, triangles, hexagons, waves, memphis,
# (SVG, embedded)   confetti, circuit, starfield, zigzag, seigaiha, plus,
#                   diamonds, bubbles, leafy, herringbone, rings, crosshatch2,
#                   terrazzo, scales, stars_small, toxic
# photo wallpapers: photo_mountain, photo_forest, photo_ocean, photo_city,
# (JPEG, embedded)  photo_desert, photo_dunes, photo_leaves, photo_sky,
#                   photo_coast, photo_woods, photo_alps, photo_pines,
#                   photo_planks, photo_marina, photo_harvest, photo_canal,
#                   photo_village, photo_trail, photo_lights, photo_greenery

Image wallpapers (SVG patterns + photos, in chatgen/assets/wallpapers/) are base64-embedded into the output, so the HTML stays self-contained. Preview them all on one conversation: python examples/wallpaper_grid.py.

(Or pass any raw CSS background value — color, gradient, or url(...) — directly.)

Chat peek preview (long-press)

iOS shows a peek preview when you long-press a chat in the list: the conversation pops up as a scaled, rounded floating card over the blurred + dimmed chat list, with a context menu below. There's no dedicated mode for this — you compose it from the renders you already have: the inbox (generate_preview) is the blurred backdrop, a normal conversation (generate) is the card, and a small context-menu HTML is rendered on its own. Pillow stitches them together (blur, dim, round corners, drop shadow), so fonts, emoji and icons stay pixel-accurate because every piece is a real render.

pip install "chatgen[screenshots]" pillow
playwright install chromium
python examples/gen_peek.py        # -> examples/out/tg_peek.png

The script (examples/gen_peek.py) is the reference recipe — the moving parts:

1. Backdrop — gen.generate_preview(chats, "telegram", view, Theme.DARK), screenshot the .cg-device, then Pillow GaussianBlur + a ~45% black blend.
2. Card — gen.generate(dialog, "telegram", view, Theme.DARK); read the .tg-nav (header) and .tg-input (composer) box geometry and crop between them so the card has no OS status bar and no input field, like the real peek. Scale to ~92% width, apply a rounded-corner alpha mask + a blurred drop shadow.
3. Context menu — a tiny standalone HTML (translucent dark panel, monochrome SVG icons) screenshot with omit_background=True, so the blurred backdrop shows through the vibrancy panel when composited.
4. Compose — alpha_composite shadow → card → menu onto the backdrop.

Swap "telegram" for any platform with an inbox (generate_preview) to peek a different app; adjust the menu rows/labels and the card crop selectors to match that platform's header/composer classes.

Adding a platform

Platforms are plugins. Create a renderer, a screen.html, and a style.css:

# chatgen/platforms/<group>/<name>/renderer.py
from chatgen.platforms.base import Capabilities, PlatformRenderer
from chatgen.registry import register_platform

@register_platform("signal")
class SignalRenderer(PlatformRenderer):
    capabilities = Capabilities()          # toggle off unsupported content types
    kwargs_schema = {"accent": "#3a76f0"}  # platform-specific options + defaults

    def build_context(self, dialog, device, theme, **kwargs):
        other = dialog.others[0] if dialog.others else None
        return {"header_name": other.name if other else "Signal"}

Templates live in <name>/templates/screen.html (import shared macros with {% import "macros.html" as m %} and use m.content_block(msg, caps, "<prefix>")), styled by <name>/style.css. Register the module in chatgen/platforms/__init__.py.

Examples gallery

python examples/generate_gallery.py
# open examples/out/index.html

Development

Managed with uv:

uv sync              # create .venv with the project + dev group
uv run pytest -q     # run the test suite
uv build             # build sdist + wheel into dist/
uvx twine check dist/*

CI runs the suite on Python 3.10–3.13 (.github/workflows/ci.yml).

Releasing (PyPI)

Publishing is automated via PyPI Trusted Publishing (OIDC — no API token stored).

1. One-time: on PyPI, add a GitHub publisher for project chatgen → owner RuNeira, repo screenshots-generator, workflow publish.yml, environment pypi.
2. Bump version in pyproject.toml, commit.
3. Tag and create a GitHub Release (vX.Y.Z). The publish.yml workflow verifies the tag matches the version, builds, and uploads to PyPI.