@aptos-labs/script-composer-pack
Build batched Aptos Move script payloads using the dynamic transaction composer — with the WASM pre-bundled and base64-inlined, so no network fetch or manual asset loading is required at runtime.
What this package does
This package bundles the @aptos-labs/aptos-dynamic-transaction-composer WebAssembly module
directly into JavaScript, eliminating the need for runtime WASM file loading or manual
initialization. Call initSync() once, then use TransactionComposer to compose and serialize
batched Move function calls into a script payload.
This is a low-level, zero-dependency binding. For a higher-level SDK with transaction
building, signing, and submission, see
@aptos-labs/script-composer-sdk.
Compatibility
| Peer dependency | Supported range |
|---|---|
@aptos-labs/ts-sdk | ^3.0.0 || ^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 |
@aptos-labs/aptos-dynamic-transaction-composer | ^0.1.8 |
Node.js 18+ required.
Install
# pnpm
pnpm add @aptos-labs/script-composer-pack \
@aptos-labs/aptos-dynamic-transaction-composer \
@aptos-labs/ts-sdk
# npm
npm install @aptos-labs/script-composer-pack \
@aptos-labs/aptos-dynamic-transaction-composer \
@aptos-labs/ts-sdk
# yarn
yarn add @aptos-labs/script-composer-pack \
@aptos-labs/aptos-dynamic-transaction-composer \
@aptos-labs/ts-sdk
Both peer dependencies must be installed by the consumer.
Usage
import {
initSync,
wasmModule,
TransactionComposer,
CallArgument,
} from "@aptos-labs/script-composer-pack";
import { Aptos, AptosConfig, Network } from "@aptos-labs/ts-sdk";
import { BCS } from "@aptos-labs/ts-sdk";
// Initialize the bundled WASM once at startup — no network fetch needed.
initSync({ module: wasmModule });
// Build a batched script that calls two Move functions in sequence.
const composer = TransactionComposer.single_signer();
// First call: withdraw coins from the signer's account.
const amountBcs = BCS.bcsSerializeUint64(100_000_000n);
const [withdrawnCoin] = composer.add_batched_call(
"0x1::coin",
"withdraw",
["0x1::aptos_coin::AptosCoin"],
[CallArgument.newSigner(0), CallArgument.newBytes(amountBcs)],
);
// Second call: deposit the returned value from the first call.
const recipientBcs = /* BCS-encoded AccountAddress */ new Uint8Array(32);
composer.add_batched_call(
"0x1::coin",
"deposit",
["0x1::aptos_coin::AptosCoin"],
[CallArgument.newBytes(recipientBcs), withdrawnCoin],
);
// Serialize into a Move script payload (Uint8Array).
const scriptPayload = composer.generate_batched_calls(/* with_metadata */ true);
// Hand scriptPayload to @aptos-labs/ts-sdk to build and submit a script transaction.
To decompile a serialized script back into its function calls (useful for display or auditing):
import { generate_batched_call_payload_wasm } from "@aptos-labs/script-composer-pack";
const calls = generate_batched_call_payload_wasm(scriptPayload); // MoveFunctionCall[]
API
| Export | Description |
|---|---|
initSync({ module }) | Initialize the bundled WASM module synchronously. Call once before any other API. |
wasmModule | Pre-compiled WebAssembly.Module — pass directly to initSync. |
TransactionComposer | Core builder. Use single_signer() or multi_signer(n) to construct, then chain add_batched_call(...) calls, and finally generate_batched_calls(withMetadata) to serialize. |
CallArgument | Represents a call argument: newSigner(idx) for a signer, newBytes(bytes) for a BCS-encoded value, or the return value of a previous add_batched_call. |
MoveFunctionCall | Represents a single Move function call inside a deserialized script. |
PreviousResult | Internal: a return value from a prior add_batched_call that can be forwarded as an argument. |
generate_batched_call_payload_wasm(script) | Decompiles a serialized Uint8Array script into MoveFunctionCall[]. |
Development
pnpm install
pnpm build # outputs CJS + ESM bundles to dist/
# Preview a version bump without writing
pnpm run version:bump -- patch --dry-run
# Apply a version bump
pnpm run version:bump -- patch # or minor / major / 1.2.3
Release
Releases are automated via GitHub Actions. After merging a version-bump PR:
git tag v<version> # e.g. git tag v0.2.5
git push origin v<version>
The release workflow verifies the tag matches
package.json, checks the version hasn't been published yet, builds, publishes to npm via
OIDC Trusted Publishing, and creates a GitHub Release.
Prerequisite: an npm Trusted Publisher must be configured on npmjs.com for this repository before pushing the first tag.
License
Apache-2.0 © Aptos Labs