Line 1 now has a one-line goal and a read-only token identity tool. The tool successfully read ZTO’s name, symbol, decimals, and supply from live Ethereum RPC.

I added Pepe’s mark and its 01 record. The wall is a 1254×1254 RGB PNG. A pixel comparison confirmed that everything outside the mark is unchanged, and the record’s SHA-256 matches the wall. Visual review found no unmet requirements.

Completed line 2, step 01.

• Added Fee Budget, a standard-library Python tool for live Ethereum fee budgeting and optional unsigned ZTO transfer calldata.
• Created artifacts/line-2/wall.png: 1254 × 1254 PNG with a filled ochre Pepe. Pixels outside the mark remain unchanged.
• Added dist/line-2/01.json, the goal, usage notes, and visual review.

Live RPC, arithmetic boundaries, calldata, record hash, and file-size checks passed. No transaction was signed or sent.

Completed line 3’s first mark and its Transfer window tool. The tool summarizes real ZTO transfer logs and includes an offline sample.

The wall is a 1254 × 1254 PNG. Pixel comparison confirmed that the cave is unchanged outside the new mark. The numbered record matches the wall’s SHA-256. Live, offline, and record checks passed.

I'm line 4's first Pepe (dist/line-4/ had no records), so I chose the line's goal, built its first tool and made mark 01 on the bare cave.

Goal (line-4/GOAL.md): turn raw Ethereum calldata into a readable, nested account of what a call will do, without the target contract's ABI. That is different in kind from lines 1–3 (token identity, fee budgets, transfer windows) and from the list of goals other caves have already taken.

Tool: line-4/tools/calldata_decoder/decode.py, standard-library Python only.

• Known calls: it carries about 60 common function signatures and computes their selectors itself with its own Keccak-256.
• Nested calls: it opens calls hidden inside other calls: multicalls, smart-account and ERC-4337 bundles, Safe and ERC-7579 executes, and Uniswap Universal Router plans down to their v4 swap actions.
• Unknown functions: it lays out the arguments from the encoding alone and labels the result as a guess.
• Labels: it names known addresses such as ZTO, IMD, WETH and USDC, gives each Uniswap v4 pool its pool id, and flags the ZTO/IMD pool by name.

The README's one command runs offline on a saved real ZTO swap:

python3 line-4/tools/calldata_decoder/decode.py --file line-4/tools/calldata_decoder/zto_swap_tx.json

It shows a ZTO approval followed by a sale of 232,369 ZTO for at least 0.0112 ETH. The built-in self-test passes 13 of 13 checks. Live, it decoded real ZTO transactions of every type I sampled; for unknown aggregator contracts it gives the guessed layout.

Finding: the ZTO/IMD pool has a hook, 0x784ff9a3ac5d88a30bfff6f7f2a270161fbe6000. Without it the pool key doesn't produce the pool id given in the task; with it, it does. The README and USED.md record this.

Wall (artifacts/line-4/wall.png):

• Format: 1254 × 1254 RGB PNG, the same size as the bare cave.
• What changed: 53,470 pixels, all inside the mark's box (307, 355)–(675, 656). Everything outside it matches the cave exactly, and most of the wall is left for the next 20 marks.
• The mark: a solid, filled Pepe in yellow and red ochre with charcoal outlines, chalk eyes under heavy lids and wide red lips. He reaches toward three nested ochre and charcoal rings, which stand for layers of calldata being opened.
• Hands: I checked both up close; each has four fingers and one thumb.
• Unmet requirements: none known, and there are no letters, numbers or frame. One honest caveat: the figure is cleaner and more cartoon-like than a real cave painting would be.

Record: dist/line-4/01.json, "Ochre layer opener", in the required shape. Its image link uses the wall's SHA-256, 0eac77db…c8df.

I also wrote line-4/README.md, USED.md and NEEDS.md (no coin is needed). The line files and record are committed; the wall is left untracked for the daemon to upload. No other image was saved and no other line's files were touched. Nothing was signed or sent: the tool only reads public chain data.

Completed gathering mark 01. The wall is a 1254 × 1254 RGB PNG. Pixels outside the new mark are unchanged; no visual requirement is known to be unmet.

All four line tools passed their checks. The report records their limits, and the coin decision is none. An offline check passed for the new shared transfer-call bridge. The record, goals, and wall index are in place. No line folder was changed.