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ddc decompiles Android DEX bytecode back into readable Java — at real-world app scale, queryable like a database, and quality-first: every one of the 909,689 files it emits across seven real-world APKs passes javac's parse gate, and every file is simplified by an exact, semantic-preserving source pass.

Highlights

• Quality first, not just fast — the full output of all seven benchmark APKs (reqable, Telegram, WhatsApp, weibo, weixin, qq, lark — 0.91M files) passes javac's parse gate with zero syntax errors, and a full-classpath javac battery tracks semantic regressions (~7,500 ddc-attributable errors across 0.91M files, down from 11,345). By default every file then goes through cure, an exact semantic-preserving source pass that inlines register-copy chains, folds if/else assignments into ternaries, recovers for-each, and drops dead stores: −15% output lines with identical gate results. Case-variant name pairs (X/Cua vs X/cua) keep separate files instead of the last one silently overwriting.
• Fast — a 226 MB / 20-dex APK (weibo, 98k classes) fully decompiles in ~19s at high quality (~9.7s with --fast), a 62 MB app (Telegram) in ~6.4s (~3.9s with --fast); pathological classes run on deadline-bounded monitored threads instead of hanging the run.
• Progressive decompilation — 15 query subcommands (strings, cross-references, hierarchies, manifest, resources, per-method decompiles) answer in milliseconds: query metadata first, decompile on demand, skip the full run entirely.
• DEX 035–041, complete — multi-dex APKs, XAPK/APKS/APKM containers, invoke-custom; lambdas and string concats fold back into real Java ((a) -> …, Cls::name, a + b).
• Readable output — jadx-style local names (str, getName() → name, Kotlin Intrinsics parameter strings) instead of v12; IntDef literals render as their constants out of the box (setVisibility(8) → View.GONE; a built-in android-37 domain table, --symbols overrides); Kotlin null-check noise is elided and synthetic access$NNN bridges inline at their call sites.
• Reproducible output — no timestamps; two runs diff cleanly.
• HTTP REST + MCP, built in (xyz-rust): ddc serve exposes every query as a REST route (GET with query params or POST with a JSON body) plus GET /openapi.json and a streamable MCP endpoint at /mcp — point an MCP client at http://addr/mcp; ddc http is REST-only (no /mcp); ddc mcp stdio|http exposes the 10 core queries as MCP tools with input and output schemas. Query commands take --format auto|text|table|markdown|md|json|jsonl (auto: table on a terminal, the stable text form when piped).
• Bilingual CLI — messages localize automatically (DDC_LANG=zh|en forces; English fallback).
• Built on jdc-core, the machine-neutral core shared with jcdc.

Install

macOS (Homebrew):

brew install ejfkdev/tap/ddc

Windows (Scoop) — add the bucket once, then install by name (scoop does not resolve a bare user/repo/app form — issue #3):

scoop bucket add ejfkdev https://github.com/ejfkdev/scoop-bucket
scoop install ddc

# or install straight from the manifest URL, no bucket needed:
scoop install https://raw.githubusercontent.com/ejfkdev/scoop-bucket/main/bucket/ddc.json

Windows (WinGet) — the package is live in microsoft/winget-pkgs:

winget install --id ejfkdev.ddc -e --source winget

Any platform (npm) — @ejfkdev/ddc is a small wrapper that downloads and SHA-256-verifies the release binary (Node 18+):

npm install -g @ejfkdev/ddc

If install scripts are disabled, the ddc launcher downloads the binary on first use. GitHub Packages is also available for users with a token that has read:packages:

npm config set @ejfkdev:registry https://npm.pkg.github.com/
npm config set //npm.pkg.github.com/:_authToken "$GITHUB_TOKEN"
npm install -g @ejfkdev/ddc

Without any package registry:

# replace with the release you want
VERSION=0.1.33
npm install -g "https://github.com/ejfkdev/ddc/releases/download/v$VERSION/ejfkdev-ddc-$VERSION.tgz"

cargo-binstall (any platform — fetches the prebuilt release binary instead of compiling):

cargo binstall ddc-cli

Arch Linux — the AUR package will be ddc-bin, but AUR registration is currently closed (HTTP 503). Install the release bundle manually in the meantime (requires base-devel):

# replace with the release you want
VERSION=0.1.33
curl -LO "https://github.com/ejfkdev/ddc/releases/download/v$VERSION/ddc-bin-$VERSION-1-aur.tar.gz"
tar xzf "ddc-bin-$VERSION-1-aur.tar.gz"
cd ddc-bin && makepkg -si

Once AUR registration reopens: yay -S ddc-bin or paru -S ddc-bin.

Binaries: every release ships raw binaries (no archives) for linux-amd64, linux-arm64, windows-amd64, windows-arm64, macos-amd64 and macos-arm64 — non-macOS builds UPX-compressed.

From source (Rust stable):

cargo install ddc-cli        # from crates.io, compiles locally

# or build the checkout:
git clone https://github.com/ejfkdev/ddc && cd ddc
cargo build --release

Package manifests and release bundles are generated from packaging/; see packaging/README.md for AUR/WinGet/npm status and multi-program support.

Usage

ddc app.apk                          # full decompile → app-out/
ddc app.apk -c com.example.Foo       # one class to stdout
ddc app.apk -o - | less              # everything to stdout

ddc info app.apk                      # app context (label via arsc, package,
                                      # version, md5) + per-dex counts
ddc listclasses app.apk              # package tree with class counts
                                      # (--full: raw names)
ddc mainactivity app.apk             # entry point: package + launcher
ddc findrefs app.apk string token    # every const-string "token" site
ddc getmethod app.apk Foo.toString   # one method, all overloads
ddc pkg app.apk --app -o own/        # the app's own code only

Full options and examples: ddc --help (subcommand menu grouped by workflow). The complete reference — every option's semantics, every subcommand's output format and behavior — lives in docs/cli.md (中文).

Performance

Seven real-world APKs, release build, measured after a cooldown (Apple Silicon, 6P+12E). The 39-APK validation corpus (4.08M decompiled files, per-APK wall time / peak RSS / javac parse gate) is in docs/validation.md (中文).

Full decompile — 7 real-world APKs

APK	Size	Full decompile	--fast	Peak RSS (full)
reqable	34 MB	0.76s	0.46s	317 MB
Telegram	62 MB	6.43s	3.86s	931 MB
WhatsApp	139 MB	23.25s	10.34s	1114 MB
weibo	226 MB	19.10s	9.73s	1383 MB
weixin	268 MB	33.20s	21.94s	1519 MB
lark	398 MB	22.29s	12.70s	2403 MB
qq	374 MB	47.70s	33.51s	2552 MB

Recorded 2026-11-02 with the current main build (post-v0.1.33): three serial runs per cell (arithmetic mean; peak RSS is the run maximum). Peak RSS is /usr/bin/time -l. WhatsApp's full run hits the deadline guard on one pathological class (X.K2H) and exits 1 after writing 99,482 files; its timing includes that deadline.

Query subcommands on the same APKs (cells: time / peak RSS; strings -f <package> --with-locations, findrefs on the package string and method onCreate, hierarchy/disasm/getclass on each app's launcher class):

Query subcommands — 13 commands × 7 APKs

Command	reqable	Telegram	WhatsApp	weibo	weixin	lark	qq
info	0.10s / 14MB	0.18s / 24MB	0.42s / 58MB	0.67s / 72MB	0.79s / 60MB	1.15s / 111MB	1.15s / 92MB
listclasses	0.01s / 19MB	0.03s / 54MB	0.04s / 67MB	0.11s / 214MB	0.15s / 220MB	0.16s / 159MB	0.25s / 205MB
manifest	0.00s / 12MB	0.00s / 19MB	0.00s / 26MB	0.01s / 49MB	0.01s / 37MB	0.00s / 34MB	0.01s / 54MB
mainactivity	0.02s / 19MB	0.05s / 69MB	0.03s / 83MB	0.16s / 206MB	0.16s / 214MB	0.13s / 153MB	0.17s / 210MB
res	0.00s / 12MB	0.00s / 20MB	0.00s / 27MB	0.01s / 57MB	0.01s / 37MB	0.00s / 36MB	0.02s / 57MB
largest	0.01s / 19MB	0.02s / 56MB	0.04s / 137MB	0.07s / 176MB	0.08s / 178MB	0.10s / 198MB	0.17s / 287MB
strings	0.01s / 20MB	0.03s / 56MB	0.11s / 118MB	0.19s / 176MB	0.24s / 191MB	0.13s / 198MB	0.47s / 297MB
findrefs-string	0.02s / 29MB	0.03s / 80MB	0.04s / 218MB	0.07s / 410MB	0.07s / 446MB	0.05s / 268MB	0.12s / 602MB
findrefs-method	0.02s / 29MB	0.05s / 93MB	0.04s / 221MB	0.06s / 399MB	0.07s / 409MB	0.08s / 494MB	0.13s / 562MB
members	0.01s / 19MB	0.02s / 56MB	0.03s / 68MB	0.08s / 175MB	0.08s / 185MB	0.11s / 145MB	0.17s / 176MB
hierarchy	0.01s / 19MB	0.03s / 53MB	0.02s / 61MB	0.09s / 189MB	0.10s / 194MB	0.10s / 148MB	0.13s / 182MB
disasm	0.02s / 19MB	0.05s / 62MB	0.03s / 58MB	0.09s / 194MB	0.13s / 199MB	0.07s / 122MB	0.12s / 155MB
getclass	0.03s / 33MB	0.24s / 133MB	0.22s / 266MB	0.49s / 407MB	0.59s / 581MB	0.77s / 710MB	1.40s / 884MB

Documentation

Architecture	crates, the lift/structure/emit pipeline, DEX versions, invoke-custom (中文)
CLI reference	every option and subcommand, in detail (中文)
Subcommands	the progressive-analysis reference (中文)
Benchmarks	timings, memory, methodology, ASC comparison (中文)
Performance engineering	5min → 6s: six rounds, measured dead ends (中文)
Corpus validation	39 real APKs, 4.08M files, javac parse-clean, bugs found & fixed (中文)

Known limitations

Erased types (DEX has no Signature); d8-desugared -$$Lambda$ classes stay separate files; a few R8 monster methods degrade via timeout (and a handful of deadline-truncated ones can vary between runs); pattern-switch renders as desugared dispatch chains. The javac gate above is a SYNTAX gate — semantic diagnostics (missing Android classpath, and in rare register-heavy monster methods a type-confused local) remain in the output. For scale: a full-classpath javac battery over four corpora currently sits at ~7,500 ddc-attributable errors across 0.91M files (v0.1.19 measured 11,345 — see benchmarks); jadx on the same battery lands at roughly half that, the gap concentrated in type recovery. Details: architecture.

Testing

cargo test    # 101 tests

License

MIT © ejfkdev