FOLLOW THE MECHANISM
- 1Call
A transaction selects a function and arguments.
- 2Check
The program evaluates permissions and conditions.
- 3Execute
State and asset balances change together under the rules.
- 4Outcome
Success or reversion is recorded; resource charges may remain.
A conceptual sequence. Real implementations can add steps, intermediaries, and conditions.
A program with a persistent address
On Ethereum, a deployed contract has code and storage associated with an address. Transactions and calls invoke its functions. The program evaluates the inputs and current state, then changes state or reverts according to its rules. A contract does not normally wake itself up at a wall-clock deadline: someone must trigger an eligible transaction, possibly through an external automation service. Execution consumes resources even when the intended action fails.
Assets move under explicit permissions
A contract can hold native assets, track token balances or receive permission to spend tokens held elsewhere. These arrangements create different exposures. Depositing collateral transfers control under a protocol’s rules; granting an allowance authorizes specified future spending; merely reading a contract changes nothing. A useful explanation identifies the asset location, authorized caller and conditions for release rather than treating every wallet interaction as equivalent.
Composition connects both benefits and failures
One contract can call another, allowing a swap, collateral deposit and borrowing operation to occur in a coordinated transaction. The transaction may revert if a required step fails. This atomicity does not eliminate dependencies: unexpected token behavior, a manipulated oracle or a faulty external contract can affect the whole application. Public source code and audits can help review, but neither is a mathematical guarantee that every permitted behavior is safe.
Upgrades change the control question
Some contracts are intentionally fixed; others use proxy arrangements or administrative permissions to change behavior. Emergency powers may pause activity or adjust parameters. These capabilities can support maintenance while creating concentrated authority and compromise risk. “Code is law” leaves out who can change the effective code, who supplies external facts and how users exit. Read the running implementation and permission structure rather than relying only on the front-end description.
MAKE IT CONCRETE
Automation without a calendar alarm
Imagine a contract permits a payout after a specified time. Passing that time makes a payout transaction eligible; it does not necessarily cause the contract to submit a transaction itself. A user or automated keeper must call the function and pay or arrange the execution cost. The time condition and the triggering service are separate dependencies.
FAILURE PATHS & COMMON MISREADINGS
Where the model can break
- An audit is evidence of review, not a guarantee against loss.
- An upgrade administrator may have more authority than ordinary users expect.
KEEP EXPLORING