cellar

Este documento também está disponível em português.

A searchable archive of Meta's shipped client source. Download a WhatsApp Web revision, diff it against another, read any module, and trace what depends on what.

WhatsApp Web ships as tens of thousands of minified JavaScript chunks. Each chunk packs many __d("ModuleName", [deps], factory, id) definitions onto a single line. cellar downloads a client revision, parses it with the oxc AST, and writes one file per module, named after the module. The result is a directory that grep -r, your editor, and your coding agent all work on directly.

Features

• Download and manage source bundles for any past client revision.
• Diff two revisions through a named filter, in JSON, NDJSON, Markdown or text.
• Search modules by name, source text, or exported symbol.
• Print any module's source, dependencies, dependents and exports.
• Build dependency and dependent graphs, as JSON, DOT or Mermaid.
• Serve all of the above to a coding agent over MCP.
• Supports whatsapp, messenger, facebook and instagram.

Requirements

• A recent stable Rust toolchain (1.95 or newer).
• just, which runs the install and CI recipes.
• Around 1.3 GB of disk per indexed revision.

Installation

Install just first:

brew install just        # macOS
cargo install just       # anywhere Rust works

Other options, including Debian, Fedora, Arch, Nix, Scoop and a prebuilt binary, are in just's install guide.

Then build cellar:

git clone https://github.com/polymorfa/cellar
cd cellar
just install

That puts cellar at ~/.cargo/bin/cellar. Make sure ~/.cargo/bin is on your PATH.

Documentation

Full documentation, including a worked example that uncovers an unannounced feature in four commands, is at cellar.mintlify.site.

Page	What it covers
AI assistants	MCP setup for Claude Code and Codex, and the sixteen tools
A real example	Finding passkey device linking before it shipped
Managing versions	Download, import, inspect and remove releases
Finding code	Search by name, source or exported symbol
Comparing releases	Diffs as text, JSON, NDJSON or Markdown
Graphs	Dependency graphs as Mermaid, Graphviz or JSON
Filters	Cutting 187,000 modules down to what matters

Every command also links to its own page from --help.

Project layout

Crate	Role
cellar-core	Store layout, index model, filter engine, diff, graphs. No I/O beyond the filesystem.
cellar-index	oxc bundle parsing into a module index.
cellar-fetch	Revision discovery, download and unpacking. The only crate that reaches the network.
cellar	CLI and MCP server, both built on one shared operations layer.

Development

just ci        # fmt-check, clippy, tests, skill check

No test may reach the network. CI enforces this.

Credits

• wa-spec by vini, which extracts WhatsApp Web protocol bindings from the same bundles daily.
• whatspec by João Lucas, which extracts a typed protocol IR from the same bundles and shaped the design here.
• ProtoCocktail's wa-diff-analyzer, my earlier attempt at this problem, whose module filter ruleset is ported here as the default filter.
• WARDEN, my own reverse-engineering project, which inspired this one.
• meta-code-verify, Meta's own source-integrity extension, which documents the btarchive endpoint.

Get support

If you'd like business to enterprise-level support from Rajeh, you can book a video chat. Book a 1 hour time slot by contacting him on Discord or pre-ordering here. The earlier you pre-order the better, as his time slots usually fill up very quickly.

If you are a business, we encourage you to contribute back to the development costs of the project. You can do so by booking meetings or sponsoring below. All support is welcome from businesses of all sizes.

Sponsor

If you'd like to financially support this project, you can do so here.

Disclaimer

Caution

This project is not affiliated, associated, authorized, endorsed by, or in any way officially connected with WhatsApp or any of its subsidiaries or its affiliates. The official WhatsApp website can be found at whatsapp.com. "WhatsApp" as well as related names, marks, emblems and images are registered trademarks of their respective owners.

cellar reads publicly served client bundles for interoperability research. The maintainers do not condone the use of this project in practices that violate the Terms of Service of WhatsApp, and call upon the personal responsibility of its users to use it fairly.

License

Copyright (c) 2026 Rajeh Taher

Licensed under the MIT License. See LICENSE for the full text.