Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

• Auto
• Light
• Dark

Algorand Specifications

An Evaluation Context ECEC is a core runtime structure used during AVM program execution. It maintains all the state and metadata required to evaluate a program within a transaction (group) scope.

Below is a simplified interface example for the Evaluation Context, inspired by the go-algorand reference implementation.

These ECEC methods expose context information that remains fixed throughout the execution of a specific transaction within the group:

• RunMode() -> {SmartSignature, Application}
  Returns whether the context is for a stateless LogicSig or a stateful Application.

• GroupIndex() -> int
  Returns the index of the current transaction within its group.

• PastScratch(past_group_index int) -> map[int, StackValue]
  Retrieves the final scratch space of a previous transaction in the same group, by index.

• GetProgram() -> []byte
  Returns the bytecode of the currently executing program ECPECP.

Additional program-related accessors:

• getCreatorAddress() -> []byte — Gets the Creator address of the Application.

• AppID() -> uint64 — Returns the ID of the current Application.

• ProgramVersion() -> uint64 — AVM version for the executing program.

• GetOpSpec() -> OpSpec — Returns the Opcode Specification for the current opcode.

• begin(program []byte) -> bool — Verifies whether the given program version is supported and executable in the current context.

These ECEC reflect the evolving state of execution, may change as the transaction executes.

• PC() -> int
  Returns the current program counter of the executed application ECpcECpc.

The opcode budget limits the AVM program execution.

• Cost() -> int
  Returns the total opcode execution cost so far.

• remainingBudget() -> int
  Returns the remaining opcode budget available for execution.

• InnerTxnPending() -> []Transaction
  Returns inner transactions that are queued but not yet submitted.

• addInnerTxn()
  Adds an inner transaction to the group. Validates constraints such as group size, fees, and sender address. Used by the itxn_begin and itxn_next opcodes.

• step()
  The core transition function that advances execution one opcode at a time. See the dedicated non-normative section for further details.

These functions expose the current Ledger context to the AVM:

• getRound() -> uint64
  Returns the current round from the Ledger.

• getLatestTimestamp() -> uint64
  Returns the latest timestamp of the most recently committed block.

• accountRetrieval(), assetRetrieval(), boxRetrieval(), applicationRetrieval()
  Provide runtime access to prefetched Ledger data (e.g., foreign accounts, apps, boxes, and assets) as declared in the transaction’s foreign arrays.