Kaiju @kaijucode

@0xKorens if your tests already separate both readings, Fable usually has little to add. that's why it's last in the chain. you call it when Opus leaves two readings that both pass, since that's exactly where a test suite has a blind spot

THIS IS THE REVERSE ENGINEERING SETUP EVERY CLAUDE USER SHOULD STEAL most people decompiling with Claude never check the output against the binary. The setup: Sonnet 5.5 builds the map, Opus 5.5 explains the hard parts, and Fable 5.1 only attacks a theory that already passed its tests. Every claim needs an address, an xref or a test log, so guesses stay out of the spec. You practice on a binary where the answer is already known: cc -O2 -o samples/record samples/record.c the split: → Sonnet 5.5 ($2/$10) maps imports, strings and xrefs into function_map.md → Opus 5.5 ($4/$20) writes spec.md with 2 competing readings → Fable 5.1 ($10/$50) finds the 3 ways that spec breaks → the original binary decides who's right Fable only gets called when: → both of Opus's readings pass the tests → the logic spans a long chain of functions → you're about to build on top of it 100K input + 10K output costs about $0.30 on Sonnet, $0.60 on Opus and $1.50 on Fable. Running Fable on string dumps is how the budget disappears. the full tree CLAUDE.md sets the evidence contract (OBSERVED / INFERRED / UNKNOWN) Sonnet 5.5 maps the binary Opus 5.5 writes the spec and the minimum tests the tests run against the original binary Fable 5.1 reviews only after they pass Sonnet 5.5 turns the proven spec into code paste the tree and this prompt into Claude Code ↓ "Build a reverse engineering workflow from this tree: Write CLAUDE.md. Every claim uses CLAIM | EVIDENCE | CONFIDENCE | HOW TO VERIFY and gets an OBSERVED, INFERRED or UNKNOWN tag. On Sonnet 5.5, inventory [BINARY] into notes/function_map.md with ADDRESS | NAME | PROPOSED_ROLE | EVIDENCE | CONFIDENCE. Rename nothing. On Opus 5.5, reconstruct [FUNCTION] into notes/spec.md with two alternative readings and the tests that separate them. Run the tests against the original binary and log every result in evidence/. Call Fable 5.1 only if both readings survive. Show me the function map first and wait for my go." save it before your next decompile.

Kaiju @kaijucode

3 days ago

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@lostinazeroy thanks

@insomnia_vip AI trading keeps getting better

@Principia_X

before writing any code for a new idea i do this now: make a stripe payment link (takes about 4 minutes), put it on a one-page site with 3 lines describing the product, post it in 2 communities. if nobody clicks buy in 7 days, the idea goes in the trash. ai made building fast, but it can’t tell you if anyone wants the thing.

@Atlas_fomo thank you!

F*ck YES... I made a prompt that stops Claude from making things up while it reverse-engineers a binary the shift: Sonnet 5.5 maps the binary for cents → Opus 5.5 rebuilds the hard logic → Fable 5.1 only reviews what already passed tests here’s 3 step guide: step 1 → drop the CLAUDE.md from the image into your project root (every claim now needs an address or a test behind it) step 2 → run Sonnet 5.5 and ask for a function map: ADDRESS | NAME | ROLE | EVIDENCE | CONFIDENCE step 3 → switch to Opus 5.5 with that map and say something like: “Reconstruct the behavior of [FUNCTION]. Write a spec plus two alternative interpretations and the minimum tests that tell them apart” the result: you pay ~$0.30 per pass instead of $1.50 on Fable, and you catch the “this loop is CRC32” mistake before it lands in your code Paste it now. Then read article below to master Claude reverse engineering:

Kaiju @kaijucode

3 days ago

x.com/i/article/2111…

3 10 65 57K 123

@EugBass 😉

@EagleVisions I suspect the match will be interesting

@macintosh_busy insane

@leshuuuk hmm, interesting strategy

@slash1sol crazy idea

@scrblanc seems interesting

@skunzu interesting

It is becoming f*cking dangerous: you can now reverse-engineer old games and binaries with Claude. Sonnet 5.5 maps the code, Opus 5.5 rebuilds the logic, and Fable 5.1 hunts for what Opus got wrong 1. Compile a tiny C lab so you already know the right answer 2. Drop the evidence contract into CLAUDE.md 3. Open the binary in Ghidra and save the decompiled functions to evidence/ 4. Run Sonnet 5.5: a function map with addresses and confidence for every row 5. Hand the map to Opus 5.5: a plain-English spec plus two competing readings 6. Test every claim: the loop Claude calls “CRC32” turns out to be FNV-1a 7. Call Fable 5.1 only when Opus stalls: it finds the 3 weakest points in the spec A pass costs $0.30 on Sonnet and $1.50 on Fable, and every claim is tagged OBSERVED, INFERRED or UNKNOWN with an address or a test behind it Turn Claude into a reverse engineer that proves what it says before you build on it Grab all 3 prompts in the article below

Kaiju @kaijucode

3 days ago

x.com/i/article/2111…

3 10 65 57K 123

@fivelossSH thanks

THIS IS AN ABSOLUTE GOLDMINE FOR REVERSE ENGINEERING the Claude reversing setup almost nobody is running yet. The idea: Sonnet 5.5 maps the binary, Opus 5.5 rebuilds the hard logic, and Fable 5.1 only steps in to stress-test a theory that already passed its tests. No guess gets into the spec, because every claim needs an address, an xref or a test log behind it first. You start with a tiny lab binary where the answer is already known: cc -O2 -o samples/record samples/record.c here’s who does what: → Sonnet 5.5 ($2/$10) writes function_map.md with address, role, evidence and confidence → Opus 5.5 ($4/$20) turns the tricky functions into spec.md with 2 competing readings → Fable 5.1 ($10/$50) looks for the 3 ways that spec could be wrong → the tests check everything against the original binary Fable only gets called in three cases: → Opus left two readings open → a long chain of functions that depend on each other → a high-stakes review before you build on top of it 100K input + 10K output costs about $0.30 on Sonnet, $0.60 on Opus and $1.50 on Fable. Most people spend their Fable budget on listing strings. The rule that matters most: reference behavior comes from the original binary, so the model never grades its own code. the full tree CLAUDE.md holds the evidence contract (OBSERVED / INFERRED / UNKNOWN) Sonnet 5.5 builds the function map Opus 5.5 writes the spec, 2 alternatives and the minimum tests the tests run against the original binary Fable 5.1 reviews only once Opus’s theory is tested Sonnet 5.5 turns the proven spec into code paste the tree and this prompt into Claude Code ↓ “Set up a reverse engineering workflow based on this tree: Create CLAUDE.md. Every claim follows CLAIM | EVIDENCE | CONFIDENCE | HOW TO VERIFY and is tagged OBSERVED, INFERRED or UNKNOWN. On Sonnet 5.5, inventory [BINARY] and write notes/function_map.md with ADDRESS | NAME | PROPOSED_ROLE | EVIDENCE | CONFIDENCE. Keep every original name. On Opus 5.5, reconstruct [FUNCTION] into notes/spec.md with two alternative interpretations and the minimum tests that separate them. Run the tests against the original binary and save every result in evidence/. Only if both readings survive, hand the spec to Fable 5.1 and ask for the 3 highest-impact ways it could be wrong. Show me the function map first. Nothing gets reconstructed until I say go.” save it, you’ll need it later.

Kaiju @kaijucode

3 days ago

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3 10 65 57K 123

@0xwhippa thank you!

@tonyprediction thanks

@nolantoken This is the trendiest format