wavi-lib 0.2.0

WhatsApp automation via vision: screenshot → OCR → click

wavi — WhatsApp Web Automation via Vision

CLI tool for WhatsApp Web automation. Extracts message history using a vision pipeline (screenshot → OCR → bubbles), and handles navigation and sidebar state via DOM scraping.

Commands

Command	What it does	Approach
wavi connect [session]	Start Chrome daemon, authenticate via QR	—
wavi status [session]	Check if daemon is alive and authenticated	DOM
wavi get <contact>	Extract full message history from a chat (--grow to page through in chunks)	Vision
wavi send <contact> <message>	Send a message	DOM + keyboard
wavi check-updates [session]	Detect new inbound messages in sidebar	DOM
wavi list-contacts [session]	List all contacts in the "New chat" panel	DOM
wavi queue [session]	Show operation queue status	—
wavi stop [session]	Gracefully shut down the Chrome daemon	—

Architecture

Vision pipeline (wavi get)

Screenshot → Crop chat panel → Color-mask detection → Bbox extraction
    ↓
    OCR (tiled) → Timestamp extraction → Message classification → Bubble list

Used for message content because WhatsApp Web obfuscates the message DOM in ways that make direct scraping unreliable.

Key files: element_detector.py, vision.py, runner.py

DOM scraping

Navigation and sidebar state use JavaScript evaluated directly on the page. Each JS constant in session.py has a comment documenting its key selector and the vision-based fallback to implement if the selector breaks after a WA update. When a DOM-scraped feature stops working, check session.py → "DOM scraping inventory" block at the top.

Chrome daemon

Chrome runs as a long-lived background process (started by wavi connect). Playwright connects and disconnects for each operation without ever killing Chrome. Killing Chrome mid-session corrupts WA's IndexedDB and invalidates the session. Shutdown is done only via wavi stop, which navigates to about:blank first so WA can flush state.

Setup

# Install uv if needed
curl -LsSf https://astral.sh/uv/install.sh | sh

git clone <repo> && cd wavi
uv sync

Quick start

# 1. Start daemon and scan QR
wavi connect

# 2. Extract message history
wavi get "Contact Name"

# 2b. Long chat — page through in blocks of 10 iterations
wavi get "Contact Name" --grow --max-iter 10   # block 1
wavi get "Contact Name" --grow --max-iter 10   # block 2 (continues where block 1 stopped)
# repeat until "history is now complete" or no more messages

# 3. Poll for new messages
wavi check-updates           # first run: saves baseline
wavi check-updates           # subsequent: no_updates or updates + contact list

wavi get flags

Flag	Behavior
--max-iter N	Stop after N scroll iterations (default 300). In --grow mode, N counts only new-content iterations per run.
--from YYYY-MM-DD	Stop scrolling when the oldest visible day pill is before this date. Drop bubbles older than the date.
--newest	Load existing history_bubbles.json and stop the moment a known message is found. Prepends new messages. Goes toward the present.
--grow	Load existing history, fast-forward past known content, then capture N more iterations toward the past. Saves a grow_checkpoint.json so each run continues where the last one stopped. Incompatible with --newest.
--assets DIR	Override the output directory (default output/<session>/<contact>/).
--json-out	Print the bubble list as JSON to stdout instead of the summary table.

--grow workflow for long chats

wavi get "Contact" --grow --max-iter 10   # run 1: captures first 10 new-content iterations
wavi get "Contact" --grow --max-iter 10   # run 2: fast-forwards to boundary, captures next 10
# repeat — prints "history is now complete" when scrollTop reaches 0

State is stored in output/<session>/<contact>/grow_checkpoint.json. Delete it to restart from scratch (also delete history_bubbles.json).

check-updates behavior

Compares the sidebar snapshot (last message + timestamp per chat) against the previous saved state. Reports a contact as updated only when:

• its last_message changed, and
• direction == "inbound" (outbound messages and re-reads are ignored)

Direction is inferred from tick icons (msg-check, msg-dbl-check, etc.) — present → outbound; absent → inbound.

Limitation: only the last visible message per chat is tracked. If multiple messages arrive between two checks, only the most recent is reported per contact. Use wavi get <contact> to retrieve the full history after detection.

Development

make ocr                  # compile the OCR helper to bin/ocr_vision (arm64, ~4x faster pipeline)
make hooks                # git hooks: ruff on commit, ruff+pytest on push (bypass: --no-verify)
uv run pytest tests/ -v   # unit tests (offline, mocked browser)
make corpus               # vision eval on golden screenshots (real OCR, see tests/corpus/README.md)

WAVI_TIMING=1 prints a per-stage timing breakdown of each analyze() run. Roadmap and audit: docs/plan-mejoras.md, docs/audit-checklist.md.

Key files:

• session.py — Chrome CDP connection + all DOM scraping JS (see inventory block)
• runner.py — Orchestration: vision pipeline, check_updates, list_contacts
• element_detector.py — Color-mask morphology for bubble detection
• vision.py — OCR, classification, timestamp extraction

Debugging

wavi bubbles /path/to/screenshot.png --debug

Produces screenshot_debug.png with annotated boxes:

• Green: sent messages
• Blue: received messages
• Red crosses: audio play button targets