Data flow

Status: current for the v1 core and validator runtime. Canonical validation, execution, bounded mempool admission, signed finality, gossip and durable local head tracking are connected through the running daemon.

Transaction path

canonical bytes
  -> shape/size/type decode
  -> chain and expiry checks
  -> exact account nonce
  -> resource caps and worst-case balance bound
  -> signature verification
  -> staged execution
  -> actual base-fee burn and full tip distribution
  -> receipt and state commit

The order is consensus-visible. Pre-validation failures change nothing. Execution success, REVERT and trap are included outcomes: all consume the nonce, actual resource fee and full tip. REVERT/trap restore staged writes, events and value transfer before charging.

Transfer and PoTB-native bodies execute directly. Deploy validates and stores an immutable ALVM container. Calls enter the requested function with calldata and a transaction-backed host interface. Nested calls are synchronous; a child REVERT returns status/data after restoring its subcall root, while a trap aborts the transaction. The active-address stack rejects reentrancy.

Block path

canonical block
  -> header, parent and base-price transition checks
  -> transaction-root verification
  -> transactions applied in committed order
  -> block resource-limit check
  -> state, receipt and usage commitment checks
  -> atomic state commit

Any mismatch restores the entry snapshot. Genesis supplies chain ID, initial root, limits, resource targets and prices, VM cost schedule, storage collateral rate and PoTB parameters. A cross-toolchain fixture executes the same block and publishes one canonical digest in CI.

State path

The top depth-256 sparse Merkle tree maps tagged address hashes to account leaves. Each contract owns a second depth-256 tree for tagged storage keys. Staged updates replace only the working root; commit publishes it and rollback discards reachability of newly written content-addressed nodes. Storage growth locks contract balance at the genesis rate and deletion refunds it.

PoTB-native transactions write their complete canonical body below the reserved system account. Bytecode cannot address this namespace.

Node ingress path

canonical transaction bytes
  -> canonical decode and signature verification
  -> chain, next-height price and expiry policy
  -> contiguous per-sender nonce and cumulative balance reservation
  -> owned bounded mempool storage

canonical block bytes
  -> decode into caller-sized scratch storage
  -> atomic core block execution
  -> local head publication
  -> stale/expired mempool pruning and byte-buffer compaction

local proposal
  -> FIFO selection bounded by declared transaction resources
  -> parent, height, base-price and transaction-root derivation
  -> isolated validation/execution pass
  -> state, receipt and resource commitment derivation
  -> canonical encoding and immediate checkpoint restore
  -> sync signing decision, sign and gossip proposal
  -> PREVOTE/PRECOMMIT quorum
  -> repeat execution only after finality

durable block commit
  -> append and sync finality certificate
  -> sync content-addressed node/value logs
  -> append checksummed canonical block record
  -> sync chain log and publish durable head

On restart, the node verifies the genesis-bound manifest, rebuilds hash/height indexes, removes a torn final record and opens state at the last complete block root. A validator also restores the signing journal and refuses a conflicting proposal or vote for a previously signed height/round/phase. Mempool policy is deliberately local and does not affect block validity. There is no replacement policy yet: duplicate hashes and conflicting sender/nonce pairs are rejected. Receipt/event memory remains valid until the next block attempt resets the node's execution arena.

Deferred paths

Peer discovery, transport encryption, rate-limiting policy and fee-based mempool ordering remain node/network work. The P2P transport now carries handshakes, gossip and finalized range sync (see src/net). Committee-authorised proposals, voting and finality are implemented in src/consensus/finality.c and connected by the daemon. The PoTB arithmetic and native schemas exist, but correlation-group discovery, trusted ASN observations and the epoch producer pipeline remain research work rather than invented core logic.