In this track: Execution traces and low-level calls
advanced · 4 MIN READ
Precompiles in the EVM
Special addresses can expose protocol-defined computation.
LET’S PICTURE IT
A service counter can be built into the building rather than installed as an ordinary shop.
SEE IT FOR YOURSELF
A valid counter call, step by stepStep 1 / 4
This example begins with count zero and a request to call increment(). No real contract is deployed.
This example begins with count zero and a request to call increment(). No real contract is deployed.Execution follows the code’s input and permission rules. A website button is not the access-control mechanism.The function reads zero, calculates zero plus one, and writes one to persistent storage.The accepted state contains count one. Later reads can inspect it. Events are emitted only if the code implements them.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
Recognize native execution support
Precompiles implement specified operations through client logic at designated addresses. Their behavior is not necessarily represented by ordinary deployed contract runtime code.
Use exact input formats
Each precompile defines its own byte input and output rules. A generic Solidity function ABI is not automatically the correct input encoding.
Check the chain and fork
Available precompiles, addresses and gas schedules depend on the network rules. A result assumed from another chain or older fork may not apply.
Handle failures and validation
A precompile is not a blanket guarantee that arbitrary cryptographic input is valid. Follow its documented success behavior and validate the result expected by the calling protocol.
Follow the execution
Special address → client-defined operation
Exact input bytes → specified computation
Output interpretation requires the precompile’s own format.
A local conceptual trace with explicit assumptions; this is not a trace of a live transaction.
QUICK CHECK · NO PRESSURE
Must a precompile have ordinary deployed runtime bytecode?
Client rules can implement its operation directly.