JANG BYUNGKUN 149b43ee61 fix(il2cpp): link arm64 builds whose registrations were inlined (#6989)
* fix(il2cpp): accept arm64 module arrays loaded through adrp/add pairs

A Unity 2022.3 macOS Master (LTO) arm64 build keeps no static CodeRegistration, so the module-array fallback that only decoded x86-64 RIP-relative references reported code-registration-not-found.
The registration owner now also decodes aligned adrp + add pairs in executable ranges and keeps the same exact-module-set and single-reference rules.
A minimal Mach-O fixture failed on the previous reader (47 passed / 1 failed) and passes here with four fail-closed variants (48/48 binary tests).

* fix(il2cpp): name the matched instruction form in inferred module-array limits

The inferred-array limitation always described RIP-relative LEA/MOV, which is wrong for arm64 results.
The provider now names the adrp/add pair on arm64, and the tool contract and docs cover both forms and state that a located array alone does not finish linking a Master build.
The new arm64 provider case failed before the wording change (1 passed / 1 failed) and both cases pass now.

* fix(il2cpp): accept type tables loaded without a static MetadataRegistration

A Unity 2022.3.62f3 macOS Master build inlines MetadataRegistration as well as CodeRegistration, so linking stopped at metadata-registration-not-found after the module array was found. Registration now infers the only field linking reads, the Il2CppType table, from the one run of type-shaped pointers that covers every referenced type index and whose start is loaded by the existing RIP-relative or adrp/add forms; types_field is null and the Evidence is inferred. The new arm64 and x86-64 fixtures failed on the previous reader (52 passed / 2 failed). Four run-selection variants (interior reference, run extended before the loaded address, two loaded runs, run shorter than the referenced indices) keep metadata-registration-not-found; instruction decoding and record-shape checks are not covered by these fixtures.

* test(il2cpp): pin adrp page deltas, register pairing and type-record shape

Every adrp fixture targeted its own 4 KiB page, so dropping the page delta or its sign extension, the add register check, the type-kind bound or the type-definition bound left all binary tests passing. Fixtures now reach a later and an earlier page, pair an add with a different destination or source register, break the type run with an out-of-range kind or type-definition index, and bound type-table candidates when the metadata references few type indices. Each of those five source mutations now fails 1 to 3 of 85 binary and provider tests.

* refactor(il2cpp): share Il2CppType kind decoding and document type-table bounds

The type-table fallback decoded the Il2CppType kind and class/value-type kinds separately from the type namer; both now use the Types owner. Zero and unaligned words are rejected before mapping lookup (Master sample metadata-registration search 92 to 68 ms). Docs and the limitation state that types_count is an upper bound, that a run spanning mappings or a small referenced type range can fail, and credit Cpp2IL StrippedCodeRegSupport and the data-side MetadataRegistration searches of Il2CppDumper and Cpp2IL. Master sample output is unchanged (11,031 code addresses, 37,025 type rows).

* fix(il2cpp): refuse generic instances when the type table was inferred

An inferred type table has no static MetadataRegistration, so the
genericMethodTable it would anchor cannot be located. Report
generic-methods-unsupported instead of reading from a null field.

* fix(il2cpp): fail closed when an inferred type table is not unique

Adversarial review found that the type-table fallback could pick another
type-shaped pointer table when the real one was unloaded or excluded, could
replace a static MetadataRegistration whose counts matched, and accepted a
run cut short by a mapping end. Require exactly one long-enough run in the
image, ending inside its mapping and loaded by code; skip the fallback when a
record's two counts matched; accept only assigned Il2CppTypeEnum kinds; and
look records up through the indexed file mapping so many mappings cannot
multiply the scan. Docs and limitations now describe the run length as at
least every referenced type index rather than an upper bound.

* fix(il2cpp): keep the type-table fallback cheap and its refusals exact

Review follow-ups: check that an address can lie in a mapping before the
throwing indexed lookup, so words pointing into gaps or zero-fill no longer
build an exception each (64 MiB: 74 s to under 2 s); treat a run starting at
its mapping start like one reaching its end; stop at the second long-enough
run instead of a 64-candidate capacity error; ignore ADRP/ADD pairs on
register 31; and say whether a counted MetadataRegistration was unusable or
no code-loaded run was found. Docs no longer generalize from one build or
state tool history they do not source.

* fix(il2cpp): judge type-table slots by their loaded value

The run scan read stored words, so a dyld-bound slot's placeholder could
decide whether a run qualified. Confirm each slot through readSlot and give
a run bounded by a bound or unresolved slot an unknown extent, so the
placeholder no longer changes the choice.

* docs(il2cpp): keep the failure-reason table layout

Shorten the two changed meanings so the table keeps its column widths and the
diff shows only those rows.

* docs(il2cpp): keep the reason table at its formatted width

* fix(il2cpp): read type-table record fields through the loader too

The previous change confirmed table slots through readSlot but still read
each record's kind and definition index from stored bytes. Read them with
readUInt32 and readSlot, and treat a record field the loader binds or leaves
unresolved like an unresolved slot: the run it bounds has an unknown extent.

* perf(il2cpp): share image mappings across loader-aware reads

---------

Co-authored-by: morluto <76467478+morluto@users.noreply.github.com>
2026-10-25 04:21:18 +08:00
…
…

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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.

MCP uses compact input schemas by default to reduce context overhead. Set REA_MCP_INPUT_SCHEMA_PROFILE=full in your MCP registration when you need the complete advertised field guidance and nested validation details. Both profiles keep the full tool set and canonical server validation. See "Compact input schema profile" in the MCP contracts guide.

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

rea --update is an alias for this verified workflow and accepts the same global output flags. Use rea update when combining it with other command controls.

Updater commands retain at most 4 MiB of stdout and stderr combined. Oversized metadata replies are rejected after the command exits; verbose installs continue with bounded diagnostics. Human progress output respects terminal backpressure and waits for submitted writes to finish.

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 (>=22.23.4), 24.x (>=24.22.1), or 26.12.1+, plus npm. Additional tools and host support depend on the target:

Target What REA returns Requirements and guide
Desktop installations Runtime candidates, supporting files, component markers and next probes Built-in bounded directory/header inspection; desktop applications
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
GPU code objects CUDA/HIP targets, selected kernel parameters and resources, retained PTX text Built-in static ELF/PE/fatbin/CUBIN/PTX inspection; GPU code objects
Model artifacts GGUF / safetensors metadata, tensor declarations and derived totals Built-in header inspection; optional full-file hash; model files
IL2CPP metadata Unity global-metadata.dat assembly images, type and method names and index ranges Built-in static decoding of versions 24, 27, 29, 31 and 39; no Unity required
Godot PCK Archive inventory and extraction, original header/directory facts and selected content identities Built-in static formats 2, 3 and 4; no Godot required
Rust binaries Embedded cargo-auditable crate names, versions, sources and dependency edges Built-in static ELF/PE/thin Mach-O inspection; Rust binaries
PE certificates Authenticode WIN_CERTIFICATE entries and PKCS#7 signer/X.509 identity fields Built-in static PE inspection; PE certificates
PE imports Import and delay-load DLL names, ordinals, IAT RVAs and pefile import hash Built-in static PE inspection; PE imports
ELF notes PT_NOTE/SHT_NOTE owners, types, GNU build-id and ABI-tag fields Built-in static ELF inspection; ELF notes
Apple IPS crashes .ips metadata, threads, images, registers and documented crash classes Built-in static JSON inspection; Apple IPS
Linux kernel modules .modinfo keys, __versions CRCs, this_module presence, and signature trailer Built-in static ELF inspection; kernel modules
Erlang BEAM IFF chunks, atoms, exports, imports, lambdas and the Code header Built-in static BEAM inspection; Erlang BEAM
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
APK signatures v1/v2/v3/v3.1 signers, certificate fingerprints, key rotation and digest self-consistency None (static only); inspect_apk_signature
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
PyInstaller executables CArchive members, Python version, entry scripts and extracted bytecode None (static only); Python packaged applications

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), the Kuna decompiler guide, 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

🎉 300,000 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 selected layers and dependency paths.

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.

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