Nelglor
26525706fc
* feat(managed): decode ldstr user strings in member inspection
inspect_managed_members reported every ldstr operand as a bare 0x70 token,
so an analyst could see that a method loads a literal but not which one.
Answering "where is this path or key used" required a second tool.
Read the optional #US stream and add a top-level user_strings inventory:
each distinct token loaded by an inspected method body, once, in token
order, with its #US file offset and decoded UTF-16 value. Instruction
anchors and normalized CIL digests keep their build-local tokens. A missing
#US stream or malformed item is reported against its token as partial
coverage. Evidence recorded before this field reads user_strings as null.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): collect user strings only from ldstr
A malformed ldtoken can carry a 0x70 token, which the operand decoder
classifies as a string operand. Only ldstr loads a literal, so collect
user strings by opcode.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): admit user-string tokens and failures before collecting them
Charge each distinct ldstr token to the decode budget before adding it to
the collection set, and admit each #US failure before retaining it. A
missing #US stream is now one stream-level issue rather than one per
token.
Document why the #US terminal flag is not validated: Mono and Roslyn
assemblies disagree with ECMA-335 II.24.2.4 and the runtime ignores it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* docs(managed): describe missing #US reporting and the unvalidated flag byte
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* test(managed): cover #US items that run past the stream end
An odd length whose payload crosses the end of #US, and a two-byte
length prefix that starts on the last #US byte, are both rejected as
"User string leaves #US" beside a readable literal. The test fails if
that bounds check is removed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): report reserved #US length prefixes as string failures
The compressed-length reader shared by #Blob and #US hard-coded
invalid-blob and "Metadata blob" for a reserved prefix, so a malformed
user string was published as a blob failure. The caller now names the
item it reads: #Blob keeps its code and message, and #US reports
invalid-string.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): append member inspection issues without argument spreading
inspectManagedMembersBytes gathered every producer's issues with
issues.push(...list), passing one argument per issue. A large malformed
input, such as hundreds of thousands of distinct bad ldstr operands or
MemberRef rows, overflows the stack with an untyped RangeError instead of
returning partial coverage. All six sites now use
appendManagedParseIssues, which appends one issue at a time.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): classify truncated #US and #Blob length prefixes by item
A two- or four-byte compressed-length prefix cut off by the end of the
artifact went through the generic range check and was reported as
invalid-row. The prefix reader now uses the item's own code for both
reserved and truncated prefixes: invalid-string for #US, invalid-blob for
#Blob. The unused generic range helper is removed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): retain user-string terminal flag conformance issues
* test(managed): write ECMA-335 #US terminal flags and cover flag issues
d5b7b0704 reports a #US terminal flag that differs from ECMA-335
II.24.2.4. The fixture heap always wrote 0, so its non-Latin-1 literals
now read as nonconforming. The fixture writes the spec flag, and a new
test flips one flag each way ("ok" set to 1, "it's" set to 0) and checks
that both literals remain beside one issue each.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): classify ldstr operands before collapsing a missing #US
With no #US stream, every collected ldstr operand was counted as a #US
reference and reported only as missing-stream, while the same non-0x70
operand got invalid-heap-index when the stream existed. parseUserStrings
now owns which operands are user-string tokens: any other operand is
invalid-heap-index either way, and only 0x70 tokens count toward the
missing-stream issue. The heap reader drops its duplicate kind check.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): state user-string limits in member comparisons
compare_managed_members ignored user_strings, so a method whose ldstr
literal changed at the same token, or legacy Evidence that never examined
literals, could read as unchanged with no caveat. The comparison now adds
an unknown limitation when either side predates user strings and a
not-compared limitation when literals were observed. ExportedType and
user-string inventories share one uncomparedInventory rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* docs(managed): advertise ldstr literals in member inspection help
The MCP tool description, the type_names input, and the CLI command and
--type help now say that inspect_managed_members returns the #US string
literals that ldstr loads, and that a type selection limits them to the
literals the selected types' method bodies load.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): read the empty #US entry at offset 0
ECMA-335 II.24.2.4 makes the first #US entry the empty blob: a zero
length with no terminal flag byte. ldstr 0x70000000 loads it, but the
odd-length check rejected it as invalid-string, dropping the literal and
making coverage partial. Offset 0 with length 0 now reads as "".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): reserve #US offset 0 and admit literals before scanning
Offset 0 is the reserved empty #US entry, so a nonempty item there is now
invalid-string instead of a published literal. The literal's projection
is reserved before the terminal-flag scan, so an inadmissible item fails
at the budget without reading every code unit. The scan's loop index no
longer shadows the token's heap index.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): report #US length prefixes wider than ECMA-335 assigns
compressedLength accepted an overlong encoding, such as 0x80 0x05 for a
5-byte item, without comment. It now reports whether the width is the
one ECMA-335 II.23.2 assigns, and the #US reader reports a non-minimal
prefix as an invalid-string conformance issue beside the readable
literal, like the terminal flag. readMetadataUserString returns every
issue it observes. #Blob behavior is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): check the #US length width before the empty entry
The offset-0 empty entry returned "" before the length-width check, so an
overlong empty entry such as 0x80 0x00 read as complete. The width issue
is now collected first and returned with the empty literal.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): admit #US width issues only for returned literals
The overlong-prefix issue was reserved before the fatal shape checks, so
an item that then failed, such as 0x80 0x00 away from offset 0, leaked
512 bytes of budget per token. The width issue is now built and admitted
only on paths that return the literal.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): keep #US issues out of member metadata status
User-string issues, including terminal-flag and length-prefix
conformance differences, marked metadata.status partial, so
compare_managed_members turned one-sided methods and fields into unknown
even though every member row was examined. #US issues now make coverage
partial while metadata.status describes the member inventory.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): give user strings their own coverage
#US issues entered the member coverage, so every consumer that reads it
as member coverage (application graph member facts, comparison status)
reported examined members as partial over a literal conformance
difference. user_strings is now { state, literals, issues }: #US issues
live there and never change the member coverage or metadata.status.
parseUserStrings returns that inventory directly.
compare_managed_members inspects with user strings skipped, since it
never reads literals, so a large literal cannot exhaust the decode budget
of a comparison. Its limitations state once that literals are not
compared, and the ExportedType limitations return to their main form.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): mark user strings partial when a body is not fully decoded
With user strings owning their coverage, an inspected method body that
was partial, malformed, or truncated no longer reached their state, so a
literal after the decode stopped was missing from a "complete" inventory.
parseUserStrings now marks the inventory partial unless every inspected
body was fully decoded, keeping the literals it did observe.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): mark user strings partial when a method row is omitted
A MethodDef row that failed before its body was read was recorded as an
issue and omitted, so its ldstr instructions were never scanned, yet the
user-string inventory could still read as complete. parseUserStrings now
takes the parseMethods result and stays partial whenever a method row
failed, as well as when an inspected body was not fully decoded.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): count only method rows that may hide a selected body
Any parseMethods issue marked user strings partial, including an
unreadable name on a method outside the type selection, so a fully
scanned selection read as incomplete. parseMethods now reads each row's
owner first and reports unscannedRows: rows that produced no method while
their owner is selected or unknown. parseUserStrings uses that count.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): treat unreadably named types as possibly selected
Under a type_names selection, a type whose name could not be read may be
a requested type, but its methods were skipped without counting toward
unscannedRows, so an unexamined body left user strings complete. A
method whose owner's name is unreadable now counts as possibly selected.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): judge user-string scans by CIL decoding, not body status
body.status is malformed for an invalid exception section even when
every instruction decoded, so user strings read as partial although every
ldstr was examined. The body reader now reports whether its CIL was fully
scanned, independent of exception-region validity, and parseMethods folds
unscanned bodies and unproduced rows into one unscannedMethods count that
parseUserStrings uses instead of reinterpreting body.status.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): stop deduplicating user-string issues
The inventory passed its issues through uniqueManagedParseIssues, which
serializes every issue into an unbudgeted map: about 42 MB of heap and
113 ms for 125,000 issues on Node 24. The issues are unique by
construction (one failure or per-offset conformance issues per distinct
token, one missing-stream issue), so the inventory now returns them, and
its literals, without copies.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* fix(managed): preserve selected string coverage unknowns
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: morluto <76467478+morluto@users.noreply.github.com>
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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.
Quick start · How REA works · What you can analyze · Showcases · FAQ · Documentation
npx rea-agents setup
 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
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.
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; 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.
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
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.
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:
- Installation and setup: agent registration, provider configuration, updates and uninstall.
- Readiness and troubleshooting: diagnose one agent or analysis engine.
- CLI and Evidence: commands, provider selection, snapshots, import/export and exit statuses.
- MCP contracts and agent prompts: tool results, sessions and guided investigations.
- Tool catalog: generated inventory of tools, providers and CLI commands.
- Roadmap: planned work and capability trackers.
Report vulnerabilities through SECURITY.md.
Star history
🎉 180,000 GitHub stars — thank you!
Thanks to everyone using REA, reporting bugs, requesting features, testing builds, and contributing fixes.
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
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.