77be0f6666 fix(capture): end special-scheme URL authorities at a backslash (#2767)
* fix(capture): end special-scheme URL authorities at a backslash

The native mitmproxy adapter removed transport userinfo with
`^(...//)[^/?#]*@`, so the authority ran to the last "@" before "/", "?"
or "#". For `https://example.test\part@tail` it treated
`example.test\part` as userinfo, reported `https://tail` as the
Location, and withdrew the original bytes as a transport credential.
WHATWG URL parsing, used by the shared TypeScript owner
(recordedTransportUrl.ts) and by HAR captures, ends a special-scheme or
scheme-relative authority at a backslash, so that "@" is ordinary path
text.

Locate the authority with the same boundary rule before removing
userinfo. Bytes are handled as Latin-1 text so unrelated bytes stay
identical. Userinfo before the backslash is still removed and redacted.
Add source unit tests for the adapter projection to test:python.

Fixes #2671

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(capture): skip special-scheme leading slashes before userinfo

Ending the authority at a backslash exposed a credential: for
`https://\user:pass@host/path`, WHATWG parsing skips every leading "/"
or "\" after a special scheme (and in scheme-relative references), so
`user:pass` is userinfo, but the new boundary stopped at the first
backslash and found no "@". The same applied to `https:\\user:pass@host`
and `https:user:pass@host`.

Start the authority after that whole slash run for non-file special
schemes and scheme-relative references. File URLs keep their "//"
boundary because they carry no userinfo. Load the adapter in tests with
fresh mitmproxy stand-ins scoped to its import instead of leaving them
in sys.modules.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(capture): parse URL controls and mixed network authorities

* fix(capture): distinguish native paths and URL base authorities

* fix(capture): preserve file-relative path evidence after separators

* fix(comparison): recheck historical calls-only changes (#2223)

* fix(comparison): preserve incomplete function call evidence

Keep missing, unknown, partial and unresolved call relationships unknown in function comparisons and reconstruction claims. Aggregate IDA caller and callee coverage without overwriting uncertainty.

Validate with 144 focused tests, typecheck/lint, docs checks and test discovery. Real providers were not verified; the full headless IDA session suite requires unavailable Windows native controls.

* fix(comparison): recheck historical calls-only changes

---------

Co-authored-by: morluto <76467478+morluto@users.noreply.github.com>

* fix(android): make DEX descriptor pattern portable

* fix(ci): isolate Linux Hopper process fixture inventory

* fix(capture): remove empty URL userinfo markers

* test(capture): cover empty URL userinfo markers

* test(ci): isolate Hopper process inventory fixtures

* fix(ci): declare process inventory callback

* test(ci): isolate alternate launcher process fixture

* fix(capture): keep URLs that WHATWG rejects instead of redacting userinfo

File URLs cannot carry userinfo (an "@" in a file host fails the parse),
and a special authority whose host or port WHATWG rejects fails the whole
URL. Neither has credentials, so the bridge now keeps their source text
and byte sidecar. Checked against Node's URL over 30,000 spellings: no
under-redaction, over-redaction 20,540 -> 5,865 (remaining: empty
userinfo, IPv4 range, IDNA, non-special and baseless references).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(capture): strip trailing URL whitespace and validate IP hosts and ports

The previous host check counted trailing C0 controls and spaces, which
WHATWG strips, so `https://user:pw@host ` kept its password. Trailing
C0/space is now removed from the parse view (raw offsets are unchanged).

Special hosts now also follow the WHATWG IPv4 parser (ends-in-a-number,
hex/octal parts, range) and IPv6 literal syntax (zone IDs rejected), and
ports are bounded lexically before int(), which raised ValueError past
4300 digits on Python 3.11+ and failed the whole capture.

Node URL differential over 126,000 spellings: under-redaction 8,084 -> 0,
ValueError 2,550 -> 0; remaining special-scheme over-redaction is IDNA
and the pinned empty-userinfo case. Cost: +0.6 us per URL.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(capture): redact userinfo before hosts that need Unicode mapping

A non-ASCII special host may map under UTS #46 to an accepted host
(fullwidth digits, ideographic full stops, ignored code points), so
treat it as accepted instead of running the ASCII IPv4 check on it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: morluto <76467478+morluto@users.noreply.github.com>
Co-authored-by: Lucien <164857476+dakjdakd@users.noreply.github.com>
2026-10-13 21:46:15 -07:00

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REA: Reverse Engineer Anything

One MCP for reverse engineering across binaries, applications, and runtime behavior.

See a feature you like. Understand how it works, down to the binary level.

npm version MCP tool catalog Node.js requirements skills.sh MIT license Discord

morluto%2Frea | Trendshift

Website · Guides · Showcases

Quick start · How REA works · What you can analyze · Showcases · FAQ · Documentation

npx rea-agents setup

Important

Get REA from morluto/rea, rea.tools, or the rea-agents npm package. Follow the installation and release links from these official sources. A similar repository name or copied README does not establish that a download is official.


REA launching its analysis bridge inside Hopper while inspecting a native binary



Discord
Join the Reverse Engineering Community

Discord · Q&A · Show and Tell


See a feature in an app that you want in your own product? Ask your agent to investigate it with REA. It can inspect the app without its source code, explain how the feature works, show the evidence, and build a version for your project.

REA connects your agent to tools for inspecting native binaries, JavaScript and Electron apps, .NET assemblies, and websites. You can also use the same tools from your terminal. Analysis runs locally, and results include the evidence and limitations behind each conclusion.

Setup registers REA with your agent and installs matching workflow instructions. Native analysis can use an existing Hopper, Ghidra, or IDA installation; setup can optionally install Hopper with approval. Static JavaScript analysis needs no native analysis engine.

Visit the REA website for setup instructions, illustrated guides, and real case studies.

Quick start

On Linux, Ghidra, JADX, firmware tool launches and static JavaScript/Electron analysis require a procps-compatible ps on REA's PATH for process ownership checks. Recovery steps are in docs/installation.md under "Linux owned-process prerequisite".

Set up your agent

With Node.js and npm installed, run:

npx rea-agents setup

Choose your agents, review the proposed changes, and approve them. Setup adds REA's MCP server and matching workflow instructions, with backups of existing configuration. Restart your agent afterward.

Setup supports Claude Code, Codex, Cursor, Gemini CLI, Grok Build and other agents. See installation and setup for provider configuration and manual MCP registration.

Ask your agent

Understand how search works in the Notes app, show me the evidence, and build a
similar feature for my project.

Replace Notes with your target app and the feature you want to understand.

Use the terminal

Inspect an extracted JavaScript/Electron app directory or ASAR:

npx -y rea-agents@latest analyze-javascript-application /absolute/path/to/app --json

The result includes modules, imports, Electron boundaries and their evidence. Replace the path with your target, such as "D:/apps/example" on Windows.

To install the rea command for regular use:

npm install --global rea-agents
rea --help

For native analysis, configure a provider first. See the CLI and Evidence guide for native commands, provider selection, snapshots and scripting.

Update REA

REA changes quickly, and new releases include frequent bug fixes. Keep your installation up to date.

For a CLI installed with npm install --global or bun add --global:

rea update

Bun global updates require Bun 1.2.17 or later. With an older Bun release, upgrade Bun manually before running rea update.

To refresh your agent registrations and skill, run the setup command printed by the update.

If you use npx, update your agent setup with:

npx rea-agents@latest setup

Review the setup changes and restart your agent. For one-off CLI commands, use npx rea-agents@latest followed by the command. With Bun, use bunx rea-agents@latest in place of npx rea-agents@latest.

How REA works

Your agent calls REA through MCP to inspect the target and trace relevant code. REA returns findings with their evidence. The agent uses them to ask follow-up questions, explain the behavior, or write and test an implementation. CLI commands use the same workflows.

REA investigation flow: your agent asks about a local target, REA inspects and traces it using analysis tools, and the agent uses the returned code, references and unknowns to explain, implement and test.

Open the full-size figure.

What you can analyze

REA requires Node.js 22.x (>=22.19), 24.x (>=24.11), or 26+, plus npm. Additional tools and host support depend on the target:

Target What REA returns Requirements and guide
Native binaries Pseudocode, assembly, strings, symbols, calls and references Hopper, Ghidra or IDA; native analysis
Offline ELF layout Sections, segments, original symbols/relocations and static mitigation candidates Caller-supplied pwntools on Linux x64; binary diagnostics
Go binaries Embedded compiler version, modules, replacements and build settings Built-in static ELF/PE/thin Mach-O inspection; no Go installation required
Rust binaries Embedded cargo-auditable crate names, versions, sources and dependency edges Built-in static ELF/PE/thin Mach-O inspection; Rust binaries
WASM artifact Validation, sections, exact import/export WAT forms and decoded WAT Caller-supplied WABT 1.0.42; inspect_wasm_artifact
EVM bytecode Dispatch selectors, byte offsets, inferred arguments and mutability Local raw/hex carrier on Linux x64; offline EVM guide
SQLite databases Tables, columns, indexes, views, triggers and selected ordinary-table rows Local database/WAL snapshot; Node.js 24.x >=24.15 or 26+ with native SQLite limits
Recorded Linux crashes Raw notes, every recorded thread's registers/signals and optional mapping candidates Caller-supplied pwntools on Linux x64; optional GDB/pwndbg; recorded crashes
JavaScript / Electron Modules, imports, source maps, routes, IPC and native add-on relationships Node.js and npm; Linux: procps-compatible ps; application analysis
Websites Page structure, scripts, network observations and requested screenshots A Chrome-family browser; browser analysis
Saved network captures Requests, responses, exposed payloads and source locations HAR or Fiddler Everywhere SAZ; mitmdump on Linux for native mitmproxy; capture guide
.NET assemblies Metadata, CIL instructions, declared native dependencies and build comparisons None (static only); managed-code guide
Android APKs Manifest declarations, classes, decompiled methods and references Headless JADX and a full JDK on Linux/macOS/Windows x64; Android guide
Android devices Devices, packages, processes, logs, dumps, screen captures, and APK/file transfers Caller-supplied adb (emulator or hardware); ADB guide
JEB projects Engine-backed project units, artifact digests and type/method pseudo-code A caller-started JEB client serving MCP, selected with REA_JEB_MCP_URL; JEB guide
Android resources Decoded manifest, string tables, locales and version facts Caller-supplied Apktool launcher; resource guide
Flutter apps Dart snapshot hash, per-ABI library digests and engine build provenance None (static APK parsing); Flutter guide
Firmware Regions, extraction results and native-analysis handoffs Binwalk / Unblob on Linux; firmware guide
Recorded packets Selected fields, repeated values, filters and decode-as rules Linux: TShark 4.x + prlimit; capture guide
Packet summaries Endpoints, DNS, TLS SNI, protocol distribution and HTTP requests Caller-supplied tshark and capinfos (Linux-verified); pcap guide
Recorded logic signals Decoder annotations, sample ranges and diagnostics Linux: sigrok-cli 0.7.2 + prlimit; signal recordings
Packages and resources File inventories, digests, plists, Apple bundle anatomy and extracted resources Artifact and JavaScript guide, Apple applications
Process behavior Terminal output, interactions, exit and filesystem observations, and run comparisons Linux/macOS with a native PTY; process capture

Static JavaScript and .NET inspection read the supplied files without running the application. Runtime capture runs or interacts with the selected target using your user permissions; each runtime guide describes its effects.

For offline native-binary inspection, REA also supports caller-supplied GNU objdump and Rizin. See the reverse-engineering tools guide for provider setup, CLI commands, and Evidence limitations. REA does not install or update either provider.

Native formats and host support vary by provider. See Hopper and Ghidra setup, the IDA guide (including an optional native MCP bridge), and experimental Windows Ghidra support. Ghidra also supports 16-bit DOS analysis. For large binaries, raise the provider's startup deadline with REA_GHIDRA_STARTUP_TIMEOUT_MS or REA_HOPPER_STARTUP_TIMEOUT_MS. For provider selection, see the CLI guide. Check release availability for features added since the latest npm release.

Showcases

Illustrations of the DX-Ball sound-pan, Notion clipboard-bridge, and TH04 bullet-ring showcases

DX-Ball: reconstruct a sound-pan calculation

Follow a sound call into its position-to-pan helper, inspect the instructions, and turn incomplete pseudocode into C. The reconstruction passes 3,205 original-x86 cases and reproduces all 63 compiled function bytes.

Read the case study · Reconstruction repository

Notion: trace the Electron clipboard bridge

Find the renderer's clipboard API, follow it through preload and IPC into the main process, and inspect the rich clipboard format.

Read the case study

TH04: recover a DOS bullet-ring calculation

Inspect the original PC-98 game's 16-bit instructions, recover the fixed and aimed angle calculations, and compare the reconstructed C++ with the historical compiler output.

Read the case study · Reconstruction repository

If you've used REA on something interesting, we'd love to see it. Share your case in an issue or a pull request, including the target, your question, how REA helped, and what you found.

FAQ

Which agents can use REA?

Any agent that supports local MCP servers. Setup configures the supported agents; other clients can use manual MCP registration.

Do I need Hopper, Ghidra or IDA?

Deep native analysis uses one of them. Static JavaScript and .NET inspection work without a native analysis engine. Setup can install Hopper after approval; Ghidra and IDA use your existing installations. See provider setup.

Do I need to start Hopper first?

REA starts Hopper when an operation needs it. On macOS, a first-run dialog may ask you to choose demo mode or activate your license. Complete that prompt in the same user session before your first CLI/MCP operation or unattended job. Open Hopper manually if needed. See Hopper startup and troubleshooting.

What does installing the skill from skills.sh do?

The skill supplies investigation instructions for your agent. Use npx rea-agents setup to register REA's MCP server and install the matching instructions, then restart your agent. See skill-only installation.

What code does REA return?

Native analysis returns pseudocode and assembly. JavaScript/Electron analysis recovers modules and their relationships. Your agent uses these findings to write and test an implementation; the showcases give worked examples.

Does REA upload my app?

REA analyzes targets locally. Your agent receives the tool results, and its model provider has its own data policy.

What should I do if I hit a bug?

Update first; a recent release may already fix it.

For a CLI installed with npm install --global or bun add --global:

rea update

For agent setup through npx:

npx rea-agents@latest setup

If you're using an agent, complete the setup refresh and restart it. Retry the same task. If the problem persists, open an issue with your REA version, target type, steps to reproduce and error output.

Documentation

Start with the website's worked guides. For exact options, prerequisites and result contracts:

Report vulnerabilities through SECURITY.md.

Star history

🎉 200,000 GitHub stars — thank you!

Thanks to everyone using REA, reporting bugs, requesting features, testing builds, and contributing fixes.

REA GitHub star history

Disclaimer

See DISCLAIMER.md for responsible-use guidance.

The project's position on illegal or unauthorized use covers all REA versions, distribution channels, and platforms; each copy retains its applicable licenses.

REA is for lawful research, education, interoperability, software preservation, and analysis of software you own or are authorized to examine.

Contributing

We'd love your help with REA! Open an issue to report a bug or suggest a feature, or send a pull request to improve the code or docs.

See CONTRIBUTING.md for development setup and checks, testing for verification lanes, and the architecture map for the project structure.

License

MIT

REA-authored code is licensed under MIT. Third-party material retains its own licenses and copyright notices; see Third-party notices for the dependency inventory, preserved license texts, and external-tool terms.

You must legally obtain and be authorized to use commercial tools, including IDA Pro / Hex-Rays decompilers, Hopper, and JEB, under their applicable licenses. REA grants no tool license, key, or activation entitlement. Trials and demos remain subject to vendor terms, including user, feature, automation, and output sharing restrictions. Cracked copies, stolen keys, unauthorized key sharing, and bypassing license restrictions are not authorized. This guidance does not amend MIT or third-party licenses.

Languages
TypeScript 88.5%
JavaScript 6.8%
Python 1.8%
HTML 1.5%
Java 0.9%
Other 0.4%