Abstract:
"I reversed the air conditioner, and now I can turn it on by clicking on the computer. I no longer have to look for the remote control." "I used REA to reverse the toilet. Now I can control the smart toilet in the toilet while sitting in front of the computer!"
Picture source Twitter@ExplosionCaptainNEXT
"Thank you REA, my HP printer can finally use third-party ink cartridges!"
If the most popular project on GitHub in the first half of 2026 is Lobster OpenClaw.
Then this title in the second half of the year should belong to REA, a reverse MCP.
REA's warehouse was actually built in April and has been updated tepidly for half a year. Until around October 7th, it suddenly exploded and topped the GitHub hot list. As of this writing, it has 223,000 stars, ranking it 23rd on GitHub’s all-time star list.
Seeing this, some friends may be curious:
What exactly is reverse engineering, and what can reverse engineering do for us?
Don't worry, you'll know soon.
Last year, I recommended a web version of Red Alert to everyone.
This is a project made by a Romanian developer to allow everyone to play Red Alert when they open a web page. Since there was no source code, he could only calculate and restore the game logic frame by frame based on the screen recording of "Red Alert 2", and he had been working on the code for 5 years.
This is called replicating, also called black box rewriting.
As for reverse engineering, it is to disassemble the installation package of software and games, restore the internal logic, and see how the code is written.
For example, copy a piece of content from Notion and paste it back into Notion. The format will still be the same as before. How is this done?
If you use REA to disassemble Notion, you will find that it clips a number in the HTML of the clipboard. When pasting, the number matches and the entire content is restored locally.
If you still don’t understand, let me give you an analogy.
Re-engraving is equivalent to when you come to Hangzhou and eat a plate of West Lake vinegar fish and say, "Oh my god, why is it so delicious?" After returning home, through your memories and the lingering fragrance on your tongue, you restored the West Lake vinegar fish to your fellow villagers.
But if you sneaked into the kitchen, took a look at the chef's techniques, and copied the recipe - congratulations, you have made the West Lake vinegar fish in reverse.
One cosplay, one enters the body.
Okay, now that we know what reverse engineering is, how do we reverse it?
One of the commonly used methods for reverse engineering is
packet capture
, take a look at the data transferred between the App and the server; the other isdecompile
, restore the compiled program into code that is close to the source code and can be read by humans.In the past, this was the skill of security researchers and cracking teams, and they had to be able to use
Ghidra and IDA
For this kind of professional tool, you also need to be able to read assembly. People like you, who get a headache when seeing assembly, can't even think about it.
But this time, REA packaged these tools into MCP and connected them to AI programming tools such as Codex and Claude Code.
After installing it,
you only need to say to the AI "Use REA to help me see how this app works"
, the AI will dismantle it by itself.
What can we do if we reverse engineer the App?
There are generally two types of things that can be done: one is to move the functions hidden in the manufacturer's App to a convenient place; the other is to bypass the restrictions deliberately set by the manufacturer.
For example, netizen @JiJiJi03 lives in an old community, and his access control intercom has long since broken. He replaced it with a new access control a few years ago and can use a mobile app to open the door. However, every time the delivery boy calls, he has to put down what he is doing and browse the app.
He was wondering if he could put the door in a more convenient place? But this door-opening app was written in Flutter. He spent all his life learning and found that the interface could not be captured with ordinary packet capture tools.
A few days ago, he asked Codex to use REA to analyze the APK installation package of this app to see how the login mechanism is implemented.
Soon, GPT-6.1 disassembled the App and found the files responsible for login, interface and encryption.
Picture source Twitter @JiJiJi03
After figuring out the interface, he integrated the unlocking function into the home screen app he wrote and installed it on his idle Android machine.
Okay, now he can reach out and open the door.
Picture source Twitter @JiJiJi03
The two netizens at the beginning are similar.
A man who was too lazy to find a remote control built his own air conditioner into the menu bar of his Mac;
A team with Codex used REA to reverse engineer the WeChat mini program of the toilet. After understanding the Bluetooth protocol, they made a remote control on the computer in half an hour. With a click, the toilet lid actually opened.
Although I don't quite understand what's so cool about using a computer to control the toilet. . .
As for the netizen who reverse-engineered the printer, he falls into the second category.
As we all know, people in the world have been suffering from HP printers for a long time. It relies on a mechanism called dynamic security to identify and block third-party ink cartridges through firmware updates, forcing everyone to buy original ones.
No wonder that netizen posted a special post to thank REA.
Do you feel like your life has suddenly become better? The equipment we paid for seems to really belong to us. . .
Don't be too excited, this is still an appetizer.
With the popularity of REA, more fresh and unpopular gameplay will surely be discovered in the future.Why do you say that?
Last night, I also tried REA at home. I want to move the Mijia rice cooker, dishwasher, Xiaoai speaker, Roborock sweeper, and the water and electricity bills from Greentown Life to the menu bar of Mac, otherwise it would be really annoying to have one app for each family.
It took about an hour, and Claude Code was halfway through building the app (Claude forcibly interrupted and warned him because it involved safety).
But I looked at the operation records and found that REA didn't do much this time.
Big brands like Mijia and Stone have been reverse engineered little by little by community experts since 2017. Ready-made open source projects can be used, and REA only helps inspect the products.But you find that the key point is not:
It is precisely because there are so many people using Mijia and Shitou that it is worthy for masters to continue to reverse the trend.
But what about access control for a community and a small program for toilets? Who will help you reverse engineering?
This is what REA has changed:
Even the most unpopular products can be taken apart, and everyone has the opportunity to use reverse engineering to solve their own problems.
I have a friend named Ai Luo, who works as a teacher in the information department of a middle school. The school relies on a digital broadcasting system for ringing the bell and playing the listening test sounds every day. For any grade exam, he had to manually adjust dozens of bells in that area to avoid the bells disturbing the candidates, and then change them back the next day.
This sounds troublesome, right?
But there is no way. The human system has stopped updating a long time ago. It is even more impossible to ask the manufacturer for secondary development documents. Replacing it will cost hundreds of thousands.
After REA exploded, Ai Luo also used it
AI
Reverse the WebSocket interface of this system and rewrite a control panel.
Now, as long as he enters the exam date, region and subject, all the ringtones in the corresponding area that affect the exam will be automatically muted.
Technology has equalized power, brothers.
According to this trend, old equipment, old software, and old games that manufacturers have long stopped supporting or even disappeared from the manufacturer will have the opportunity to be reborn.
For example, some netizens bought a Mac Calendar App many years ago, but the author stopped updating it long ago, and problems began to occur on the new version of macOS. A few days ago, he used REA to take it apart and spent two and a half hours to recreate a version with almost completely restored functions.
Picture source Twitter @李布凯 is studying
Writing this, everything seems wonderful, right?
It can be reversed, is there really only beauty?
After talking to Ai Luo, we all felt that there was more of a crisis here. In his words:
We are in a period of time
AI
The era of martial arts.
The appearance of martial arts is that the people of the world are happy to grudge each other, but the essence is that they use force to break the law.
When
AI
Help us blur the boundaries of technical barriers, then the next step of blurring must be the moral bottom line.
The reason why everyone enjoys what you wrote earlier is because we are challenging business giants. "Damn, the equipment I bought doesn't entirely belong to me. I don't have this authority, and I can't touch it."
In reverse, it helped us complete the story of single-handedly challenging the giants.
But do giants have to be villains?
Just like in "I'm Not the God of Medicine", pharmaceutical companies want to recoup their costs and patients want to survive, and no one is right. The same is true in the software world: manufacturers want to make money, and users want to get back what they paid for.
Both sides are right, and the contradiction cannot be reconciled. However, it has not completely erupted for so many years. There must be a gray area in the middle to relieve pressure.
In the God of Medicine, this area is the drug dealer; in the software world, it is the reverse.
For so many years, this gray area has always been around us, but the threshold used to be very high, and only a few masters could get in. Ordinary people could only pick up some ready-made tools they left behind.
What REA does is to spread this gray area directly under the feet of every ordinary person.
The gray area is gray because one step to the left is heaven and one step to the right is hell.
The drug dealer who does good deeds is Cheng Yong; the drug dealer who does evil is Zhang Changlin who sells fake medicines.
The same goes for the reverse: using it to open doors, turn on the air conditioner, and silence the ringtone in the exam room is called digital equality; but taking a step to the right is a copyright disaster.
When many people start to take that step to the right, the first ones to be trampled are not the giants, but the small teams.
If you reverse engineer a large company's product, it can only be used as a toy at best. You can't use reverse results to make profits, otherwise you'll get a lawyer's letter.
But it is not uncommon for the products of small teams to be copied and reverse engineered.
Many softwares that Shichao has recommended to everyone will have reprinted versions popping up within a few days. For example, NoFeed, within two days of its release, a lot of them popped up on other platforms.
It only takes a few hours for others to make a product that everyone has worked hard on for months. Game developer Freya Holmér just posted a prototype video in March this year. Within a few days, several imitations using AI appeared in the App Store, beating her ahead of her.
In the past, others could only copy it based on the appearance. How to implement it still needs to be figured out.
Now that you are interested in other people's apps, use REA to dig into the binary level, reverse engineer how it is implemented, and then make your own app or simply crack it.
Many of this kind of copycat laws are still unclear legally. But before there were laws, killing was not considered a crime, but that didn't mean it was right to kill.
The arrival of REA is equivalent to giving an AK47 to every kindergarten child. Each child has extremely strong attack power and 0 defense power.
When we put a moral choice that is almost bound to slip in front of most people, do we really have the courage to test human nature? Is everyone going left or right?
So what happens next? I dare not say.
The bad reviewers can only guess that big companies will build walls first: you hold the gun, I hold up the shield. By moving all the core logic to the server, reverse engineering can only see the returned results, but not how the intermediate calculations are done.
Independent teams really don’t know what to do. This is the best of times and the worst of times.
But Aiello feels that it is a tragedy of the times that AI and AI have gone to the stage of endless attack and defense. Those computing power could have been used for more meaningful things.
He believes that the plot will be similar to that of the Medicine God:
When landslides occur on a large scale, the government will definitely intervene and the law will be forced to speed up the update.
Actually, those of us born in the 80s and 90s have also experienced these things once.
Everyone still remembers the crazy era of online piracy, when books, songs, games, and almost everything could be downloaded for free. Later, copyrights were tightened, and in July 2015, various music platforms removed more than 2.2 million unauthorized songs as required; later, everyone began to add membership to music apps and buy genuine copies in e-book malls.
Of course, it is unrealistic to rely on the law to solve all moral problems. As long as the law can hold the bottom line, the world can still move forward with patchwork.
It’s just that until the patchwork is complete, we’ll keep stepping into this gray area in the heat of REA. Some people decide to go to the left, while others choose to go to the right; some make technology more egalitarian, while others trample on originality. The world is getting better and darker at the same time.
But the human progress bar has reached this point. This is the inevitable development of AI, the only way of the times, and a story that each of us will experience.
At this time, like everyone else, I could only shout excitedly and uneasily:
Welcome to the era of great reverse.
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