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Documentation Index

Fetch the complete documentation index at: https://mintlify.com/ton-blockchain/acton/llms.txt

Use this file to discover all available pages before exploring further.

Every Tolk contract has access to a set of built-in standard library modules that are bundled with the Tolk compiler itself. These modules are distinct from the Acton standard library: the Acton stdlib provides host-side helpers for testing and scripting, while the Tolk stdlib provides the foundational language primitives that execute directly inside the TVM — cell manipulation, dictionary operations, string utilities, gas management, and low-level TVM access. The Tolk stdlib is located in the Acton binary under crates/tolk-compiler/assets/tolk-stdlib/ and is automatically available without any configuration. Most modules are implicitly imported; a few specialised ones (tvm-dicts, strings, gas-payments, etc.) must be explicitly imported with import "@stdlib/<name>".
The Tolk stdlib is on-chain code — it compiles to TVM instructions. Every function you call from it consumes gas. The Acton stdlib (@acton/) is host-side and does not run inside TVM.

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Modules

common

Primitive types, cell/slice/builder operations, map and array methods, contract storage, message creation, address utilities, and send-mode constants. This module is auto-imported into every Tolk file.

tvm-dicts

Low-level TVM dictionary operations for signed-integer, unsigned-integer, and slice-key dictionaries — get, set, delete, iteration, and more.

strings

Runtime string utilities — length calculation, content hashing, equality comparison, integer-to-string conversion, and the StringBuilder type.

gas-payments

Gas and fee utilities — acceptExternalMessage, setGasLimit, gas fee calculation, storage fee calculation, and forward fee calculation.

exotic-cells

Helpers for working with Merkle-proof and Merkle-update cells, and other exotic cell types.

lisp-lists

Methods for the lisp_list<T> type — prepend, get head, and traverse linked-list structures longer than 255 elements.

reflection

Compile-time reflection utilities — reflect.sourceLocationAsString() and related helpers used internally by expect and Assert for automatic location tracking.

tvm-lowlevel

Raw TVM instruction wrappers for advanced use cases that are not covered by the high-level stdlib surface.

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Distinction from Acton Stdlib

Tolk stdlib (@stdlib/)Acton stdlib (@acton/)
Where it runsInside TVM on-chainActon host process
Available incontracts/, wrapperstests/, scripts/
Consumes gasYesNo
PurposeLanguage primitives, TVM operationsTesting, emulation, deployment
Auto-importedcommon moduleNever

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Example: Using Tolk Stdlib in a Contract

// `common` is auto-imported — no explicit import needed
import "@stdlib/strings"
import "@stdlib/gas-payments"

fun onInternalMessage(in: InMessage) {
    var storage = MyStorage.fromCell(contract.getData());

    // map operations from common
    storage.balances.set(in.senderAddress, ton("1.0"));

    // string formatting from @stdlib/strings
    val label = int.toDecimalString(storage.count);

    // gas operations from @stdlib/gas-payments
    val fee = calculateGasFee(BASECHAIN, getGasConsumedAtTheMoment());

    contract.setData(storage.toCell());
}

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