Show HN: Explore Ethereum by the Shape of a Transaction

- A "block explorer" is a web tool (like Etherscan) that lets anyone look up individual transactions, addresses, and blocks on a blockchain — the public ledger of a cryptocurrency like Ethereum. This project is a new, alternative block explorer. - Ethereum transactions often trigger chains of internal "sub-transactions" (e.g., a DEX trade calls a swap contract, which calls a token contract). This "call tree" is the shape of those nested calls. The explorer visualizes that structure graphically and lets you click through it. - Most block explorers show raw data (hashes, amounts, gas fees); this one emphasizes the *visual topology* of how addresses interact — potentially useful for spotting patterns, suspicious activity, or understanding complex DeFi interactions. - The data covers blocks 20.8M–25.4M (roughly late 2024 to mid-2025). "The Merge" (Sep 2022) is when Ethereum switched from proof-of-work to proof-of-stake; backfilling to that point would add ~10M more blocks of history. - The creator is not trying to keep up with Ethereum's live block production in real time — this is an exploratory dataset, not a real-time monitoring tool.