Mini ETH Node

A full Ethereum client has many moving pieces: primitive types, RLP, hashing, signatures, state roots, block validation, transaction execution, receipts, networking, peer management, and chain-head updates. Reading production clients is valuable, but the size of those systems makes it difficult to isolate the core execution-node flow. Mini ETH Node narrows the scope to signed value-transfer blocks so the essential mechanics are visible end to end.

The node accepts signed value-transfer blocks over an async TCP protocol. It validates parent/head relationships, recovers transaction senders, executes transactions against in-memory state, computes receipts and gas accounting, commits blocks, updates the shared chain head, and exposes account-state and chain-head queries. A deterministic test client reconstructs genesis keys, queries node state before building each block, signs transactions, sends blocks one at a time, and resumes from the node's current head across runs.

Workspace boundaries: core/types: Ethereum-style addresses, hashes, headers, blocks, accounts, transactions, genesis config, and chain head. core/rlp-codec: RLP encoding/decoding, Keccak/RLP header hashing, ECDSA signing and sender recovery, Merkle Patricia Trie state-root calculation. core/execution: Provider traits, in-memory provider, executor, validator, value-transfer pipeline, receipts, gas accounting, nonce and balance checks, journal rollback. core/networking: TCP protocol, framed codec, connection tasks, peer manager, handshake, ping/pong, block forwarding, account-state query, and chain-head query. processor: Pending queue, out-of-order buffering, parent/head validation, execution, block commitment, stale-block rejection, and metrics. node: Runtime wiring for listener, networking manager, processor adapter, shared chain head, tracing, graceful shutdown, and deterministic test client.

Separating protocol routing from authoritative state makes the system much easier to reason about: networking never imports processor types, and the processor remains the source of truth for account state and chain-head updates. The block builder is deliberately state-light; it signs blocks from snapshots returned by the node instead of predicting execution locally. That constraint keeps test behavior deterministic while matching the way real clients should treat canonical state.