Hi, I’m ustas.
/ʲustɑs/I like making software do things its authors didn’t plan for.
Have a look through the tools and notes. There are a couple of games here, too.
Things I’ve made
- ferrumctl
Memory and coordination tools for working with coding agents.
- Cyber Codex
A Codex fork that fixes missing cyber-access selection in API requests.
Smaller tools
All projects ↗- Ledger Offline Sign Offline transaction signing
- erc20-balance Token and native balances from the terminal
- PocketGamepad Phone → PC controls
Two neighboursDifficulty: easy Share or keep. Work out their rule.
Watch their choices. Then predict three responses.
Together 0 points
Your moves (0)
| Round | You | Neighbour |
|---|
Meet a neighbour to begin.
How it works
Up to 8 exchanges with the same neighbour. They follow one fixed rule, using only earlier moves. Try different choices and watch their response.
After three exchanges, you can test your reading. We show your next move; you predict theirs. Three correct responses win; a miss ends the visit. After the last observation, the test starts automatically. Points are separate from winning.
| You ↓ · Them → | Share | Keep |
|---|---|---|
| Share | 3 / 3 | 0 / 5 |
| Keep | 5 / 0 | 1 / 1 |
The garden remembers mutual sharing: leaves after the first shared round, a flower after three. It doesn’t affect points.
This is a repeated prisoner’s dilemma with fixed rules.
Bytecode labyrinthDifficulty: medium Trace. Infer. Patch your way out.
Six chambers. Learn the machine, then decode its messages.
▲ you □ exit
Dashed bytes are editable. Editing restarts.
Your labels (0)
Your hypotheses, saved as you type. Kept on Undo and Restart.
Execution history
Need a nudge?
Controls & notation
Step executes one byte instruction. Its row lights up beside the result. The small › marks what will run next. After observing a byte, type a hypothesis into its Name field. Labels save as you type and follow the byte throughout the program.
Numbers are hexadecimal. A holds one eight-bit value; an arg is a value or a slot to jump to. Later chambers show A’s bits and the target character codes. Run skips familiar effects and pauses on new observations. Undo goes back one instruction; Restart keeps patches and labels. Execution history records raw machine states, not explanations.
This is a fictional machine, not a real processor. Produce the exact target, reach the outlined exit, then halt. No timer, no lost lives. Progress lasts for this visit.
Along the way
- +1,000 points · Ethereum execution PR #19324
- +1,000 points · Ethereum consensus PR #19323
- +2,500 points · Ethereum consensus PR #19179
- Top 2 · Wonderland CTF 2025
- Top 2 · Soon SVM on Cantina (2H, 5M)
- Created a challenge · Remedy CTF (1300+ submissions)
- Solved 3 puzzles · BlazCTF
- Top 11 · $1.1M zkSync Era contest on Code4rena
- Solved Puzzle #1 · zkHack IV
- Top 1 · Hexens x TheSecureum Bootcamp