Skip to main content

​
Introduction

This page lists the canonical fields of a user-submitted transaction and their semantics, aligning with the Cowboy whitepaper and CIPs.
Cowboy implements dual metering (Cycles and Cells) with independent EIP‑1559‑style fee markets; users set per‑meter limits and max fee/tip parameters.

​
Canonical Fields

  • nonce (u64)
    • Monotonically increasing per-sender counter. Prevents replay and enforces ordering. The state transition function validates signature, nonce, and balance before execution (whitepaper).
  • to (address, 20 bytes)
    • Target account. If the target is an EOA, the transaction performs a native transfer; if the target is an actor, the transaction invokes the actor’s handler.
  • value (u128, CBY)
    • Amount of native asset to transfer to to. For actor calls that do not transfer funds, this is 0.
  • payload (bytes)
    • Call data delivered to the target actor’s handler. The byte length is metered as Cells before VM execution begins (CIP‑3: intrinsic calldata metering).
  • cycles_limit (u64)
    • Upper bound on computational work allowed for this transaction. The VM halts with “Out of Cycles” if exceeded. Standardized and enforced to mitigate DoS (CIP‑3).
  • cells_limit (u64)
    • Upper bound on bytes that may be consumed by data events (payload, return data, storage I/O, /tmp I/O). Standardized and enforced to mitigate DoS (CIP‑3).
  • max_fee_per_cycle (u128)
    • Maximum price the sender is willing to pay per Cycle. Together with basefee_cycle determines the effective payment (CIP‑3).
  • max_fee_per_cell (u128)
    • Maximum price the sender is willing to pay per Cell. Together with basefee_cell determines the effective payment (CIP‑3).
  • tip_per_cycle (u128)
    • Optional tip to block producers, per Cycle. The effective tip paid is min(tip_per_cycle, max_fee_per_cycle − basefee_cycle) (CIP‑3).
  • tip_per_cell (u128)
    • Optional tip to block producers, per Cell. The effective tip paid is min(tip_per_cell, max_fee_per_cell − basefee_cell) (CIP‑3).
  • signature (secp256k1)
    • Signature over the transaction’s signing payload. The sender address is recovered from the signature (whitepaper: EOAs controlled by secp256k1 keys).

​
Validation and Execution (Informative)

  • Validation: The protocol validates signature, nonce, and balance. Transactions that fail validation are rejected (whitepaper).
  • Dispatch: The transaction is dispatched to to (EOA transfer or actor handler invocation) and enforced under all resource limits (whitepaper).
  • Metering and fees (CIP‑3):
    • Cycles: Computation is metered at Python bytecode/host-call granularity.
    • Cells: Bytes are charged at I/O boundaries (intrinsic calldata, storage I/O, /tmp I/O, return data).
    • Basefee is independently adjusted for Cycles and Cells (dual EIP‑1559). The basefee portion of fees is burned; tips are paid to the producer.

​
Notes

  • Idempotency is achieved through nonce semantics and single inclusion in canonical block order; see Idempotency.
  • Reentrancy is prevented by the actor model’s single-threaded, sequential mailbox processing and deterministic async scheduling; see Reentrancy.

​
Further Reading