stacks-encoding-native-js

stacks-encoding-native-js is a Node.js native addon library written in Rust, which provides functions for decoding binary/wire formats used in the Stacks blockchain. Features include Clarity values, transactions, post-conditions, Stacks and Bitcoin addresses, and more.

Various ASM/SIMD optimizations are used in areas which are prone to causing CPU bottlenecks when used in hot paths, e.g. decoding raw Clarity values on the fly.

This project was bootstrapped by create-neon.

Runtime Support

Node.js v16+

Platform Support

Linux (glibc) x86_64
Linux (glibc) aarch64
Linux (musl) x86_64
Linux (musl) aarch64
MacOS x86_64
MacOS aarch64 (Apple Silicon M1)
Windows x86_64

Installation and Usage

npm install stacks-encoding-native-js

Decoding serialized Clarity values

Example Clarity value:

Expand

(tuple 
  (active true) 
  (address 'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW) 
  (alias "Alice") 
  (balance u2000) 
  (ping (ok 250)) 
  (public_key (some 0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58)) 
  (tags (list u"contributor" u"og \u{e2ad90}" u"clarity"))
)

Decode serialized Clarity value to repr string

import * as assert from 'node:assert';
import { decodeClarityValueToRepr } from 'stacks-encoding-native-js';

// Serialized hex string of the example Clarity value (0x-prefix optional, Buffer / Uint8Array also accepted)
const hex = '0x0c00000007066163746976650307616464726573730516142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b05616c6961730d00000005416c6963650762616c616e636501000000000000000000000000000007d00470696e670700000000000000000000000000000000fa0a7075626c69635f6b65790a020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e5804746167730b000000030e0000000b636f6e7472696275746f720e000000066f6720e2ad900e00000007636c6172697479';

const reprStr = decodeClarityValueToRepr(hex);

assert.strictEqual(
  reprStr, 
  `(tuple (active true) (address 'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW) (alias "Alice") (balance u2000) (ping (ok 250)) (public_key (some 0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58)) (tags (list u"contributor" u"og \\u{e2ad90}" u"clarity")))`
);

Decode serialized Clarity value to object

import * as assert from 'node:assert';
import { decodeClarityValue } from 'stacks-encoding-native-js';

// Serialized hex string of the example Clarity value (0x-prefix optional, Buffer / Uint8Array also accepted)
const hex = '0x0c00000007066163746976650307616464726573730516142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b05616c6961730d00000005416c6963650762616c616e636501000000000000000000000000000007d00470696e670700000000000000000000000000000000fa0a7075626c69635f6b65790a020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e5804746167730b000000030e0000000b636f6e7472696275746f720e000000066f6720e2ad900e00000007636c6172697479';

// Decode into JSON object
const decoded = decodeClarityValue(hex);

Decoded Clarity value output result:

Expand

// Result object
assert.deepStrictEqual(decoded, {
  repr: `(tuple (active true) (address 'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW) (alias "Alice") (balance u2000) (ping (ok 250)) (public_key (some 0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58)) (tags (list u"contributor" u"og \\u{e2ad90}" u"clarity")))`,
  hex: '0x0c00000007066163746976650307616464726573730516142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b05616c6961730d00000005416c6963650762616c616e636501000000000000000000000000000007d00470696e670700000000000000000000000000000000fa0a7075626c69635f6b65790a020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e5804746167730b000000030e0000000b636f6e7472696275746f720e000000066f6720e2ad900e00000007636c6172697479',
  type_id: 12,
  data: {
    active: { repr: 'true', hex: '0x03', type_id: 3, value: true },
    address: {
      repr: "'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW",
      hex: '0x0516142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b',
      type_id: 5,
      address_version: 22,
      address_hash_bytes: '0x142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b',
      address: 'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW'
    },
    alias: {
      repr: '"Alice"',
      hex: '0x0d00000005416c696365',
      type_id: 13,
      data: 'Alice'
    },
    balance: {
      repr: 'u2000',
      hex: '0x01000000000000000000000000000007d0',
      type_id: 1,
      value: '2000'
    },
    ping: {
      repr: '(ok 250)',
      hex: '0x0700000000000000000000000000000000fa',
      type_id: 7,
      value: {
        repr: '250',
        hex: '0x00000000000000000000000000000000fa',
        type_id: 0,
        value: '250'
      }
    },
    public_key: {
      repr: '(some 0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58)',
      hex: '0x0a020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58',
      type_id: 10,
      value: {
        repr: '0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58',
        hex: '0x020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58',
        type_id: 2,
        buffer: '0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58'
      }
    },
    tags: {
      repr: '(list u"contributor" u"og \\u{e2ad90}" u"clarity")',
      hex: '0x0b000000030e0000000b636f6e7472696275746f720e000000066f6720e2ad900e00000007636c6172697479',
      type_id: 11,
      list: [
        {
          repr: 'u"contributor"',
          hex: '0x0e0000000b636f6e7472696275746f72',
          type_id: 14,
          data: 'contributor'
        },
        {
          repr: 'u"og \\u{e2ad90}"',
          hex: '0x0e000000066f6720e2ad90',
          type_id: 14,
          data: 'og ⭐'
        },
        {
          repr: 'u"clarity"',
          hex: '0x0e00000007636c6172697479',
          type_id: 14,
          data: 'clarity'
        }
      ]
    }
  }
});

Decode serialized Clarity value to typed object

import * as assert from 'node:assert';
import { 
  decodeClarityValue,
  ClarityTypeID,
  ClarityValueTuple,
  ClarityValuePrincipalStandard,
  ClarityValueStringAscii,
  ClarityValueInt,
  ClarityValueBoolTrue,
  ClarityValueResponseOk,
  ClarityValueBuffer,
  ClarityValueList,
  ClarityValueStringUtf8,
  ClarityValueOptionalSome,
  ClarityValueUInt,
} from 'stacks-encoding-native-js';

// Serialized hex string of the example Clarity value (0x-prefix optional, Buffer / Uint8Array also accepted)
const hex = '0x0c00000007066163746976650307616464726573730516142a7f9b4d4c7d2fdbe69c0b6733a484f37bbc3b05616c6961730d00000005416c6963650762616c616e636501000000000000000000000000000007d00470696e670700000000000000000000000000000000fa0a7075626c69635f6b65790a020000002102d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e5804746167730b000000030e0000000b636f6e7472696275746f720e000000066f6720e2ad900e00000007636c6172697479';

// Provide a typed view of the decoded value
const decoded = decodeClarityValue<ClarityValueTuple<{
  active: ClarityValueBoolTrue;
  address: ClarityValuePrincipalStandard;
  alias: ClarityValueStringAscii;
  balance: ClarityValueUInt;
  ping: ClarityValueResponseOk<ClarityValueInt>;
  public_key: ClarityValueOptionalSome<ClarityValueBuffer>;
  tags: ClarityValueList<ClarityValueStringUtf8>;
}>>(hex);

assert.deepStrictEqual(decoded.data.tags.list.map(v => v.data), ['contributor', 'og ⭐', 'clarity']);

The annotated types are not automatically checked at runtime, so type checks are needed for error handling:

Expand

assert.strictEqual(decoded.type_id, ClarityTypeID.Tuple);
assert.strictEqual(decoded.data.active.type_id, ClarityTypeID.BoolTrue);
assert.strictEqual(decoded.data.address.type_id, ClarityTypeID.PrincipalStandard);
assert.strictEqual(decoded.data.alias.type_id, ClarityTypeID.StringAscii);
assert.strictEqual(decoded.data.balance.type_id, ClarityTypeID.UInt);
assert.strictEqual(decoded.data.ping.type_id, ClarityTypeID.ResponseOk);
assert.strictEqual(decoded.data.ping.value.type_id, ClarityTypeID.Int);
assert.strictEqual(decoded.data.public_key.type_id, ClarityTypeID.OptionalSome);
assert.strictEqual(decoded.data.public_key.value.type_id, ClarityTypeID.Buffer);
assert.strictEqual(decoded.data.tags.type_id, ClarityTypeID.List);
assert.strictEqual(decoded.data.tags.list[0].type_id, ClarityTypeID.StringUtf8);

// Now we can safely access typed properties
assert.strictEqual(decoded.data.active.value, true);
assert.strictEqual(decoded.data.address.address, 'SPA2MZWV9N67TBYVWTE0PSSKMJ2F6YXW7CBE6YPW');
assert.strictEqual(decoded.data.alias.data, 'Alice');
assert.strictEqual(decoded.data.balance.value, '2000');
assert.strictEqual(decoded.data.ping.value.value, '250');
assert.strictEqual(decoded.data.public_key.value.buffer, '0x02d4dada83bff981f0cb7ebafcfc6fc7cb5e078b9ee2302a93aae19fb90f872e58');
assert.deepStrictEqual(decoded.data.tags.list.map(v => v.data), ['contributor', 'og ⭐', 'clarity']);

Decoding principals

Principal from serialized Clarity value

import * as assert from 'node:assert';
import { decodeClarityValueToPrincipal } from 'stacks-encoding-native-js';

// Serialized hex string of an example Clarity value (0x-prefix optional, Buffer / Uint8Array also accepted)
const standardPrincipal = decodeClarityValueToPrincipal('0x0516a13dce8114be0f707f94470a2e5e86eb402f2923');
assert.strictEqual(principal, 'SP2GKVKM12JZ0YW3ZJH3GMBJYGVNM0BS94ERA45AM');

const contractPrincipal = decodeClarityValueToPrincipal('0x0616a6a7a70f41adbe8eae708ed7ec2cbf41a272182014626974636f696e2d6d6f6e6b6579732d6c616273');
assert.strictEqual(contractPrincipal, 'SP2KAF9RF86PVX3NEE27DFV1CQX0T4WGR41X3S45C.bitcoin-monkeys-labs');

Stacks address from parts

import * as assert from 'node:assert';
import { stacksAddressFromParts } from 'stacks-encoding-native-js';

const stacksAddressData = {
  version: 26,
  // Serialized hex string (0x-prefix optional, Buffer / Uint8Array also accepted)
  hash160: '0xcd1f5bc9aa49e7417cee3e5dba1a92567da41af6'
};

const stacksAddress = stacksAddressFromParts(stacksAddressData.version, stacksAddressData.hash160);
assert.strictEqual(stacksAddress, 'ST36HYPY9N94YEGBWXRZ5VEGTJ9B7V90TYTM9HGTJ');

Stacks address to parts

import * as assert from 'node:assert';
import { decodeStacksAddress } from 'stacks-encoding-native-js';

const [version, hash160] = decodeStacksAddress('ST36HYPY9N94YEGBWXRZ5VEGTJ9B7V90TYTM9HGTJ');
assert.strictEqual(version, 26);
assert.strictEqual(hash160, '0xcd1f5bc9aa49e7417cee3e5dba1a92567da41af6');

Decoding transactions

import * as assert from 'node:assert';
import { 
  decodeTransaction,
  AnchorModeID,
  TransactionVersion,
  TxPayloadTypeID,
  TxSpendingConditionSingleSigHashMode,
  TxPublicKeyEncoding,
  ClarityTypeID,
  PostConditionModeID,
  PostConditionAuthFlag,
  PostConditionAssetInfoID,
  PostConditionNonfungibleConditionCodeID,
  PostConditionNonFungibleConditionName
} from 'stacks-encoding-native-js';

// Serialized hex string (0x-prefix optional, Buffer / Uint8Array also accepted)
const rawTx = '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';

const decoded = decodeTransaction(rawTx);

Decoded transaction output result:

Expand

assert.deepStrictEqual(decoded, {
  tx_id: "0x49bcdba540d5c486f6f7a71de639a128a65f0378d7571e20c75a61661dd5b469",
  chain_id: 1,
  version: TransactionVersion.Mainnet,
  anchor_mode: AnchorModeID.Any,
  auth: {
    type_id: PostConditionAuthFlag.Standard,
    origin_condition: {
      hash_mode: TxSpendingConditionSingleSigHashMode.P2PKH,
      key_encoding: TxPublicKeyEncoding.Compressed,
      nonce: "325",
      signature: "0x008b510c9e20dc22040953d9d7eabf2038008fa4d89a5a6cb78bb9d513e75cd0df3924af9ce3b5f185705bc2f6ba3071710ec6a8803ed6da4addc40a05a01ee0f5",
      signer: {
        address: "SP24ZBZ8ZE6F48JE9G3F3HRTG9FK7E2H6K2QZ3Q1K",
        address_hash_bytes: "0x89f5fd1f719e4449c980de38e3504be6770a2698",
        address_version: 22
      },
      tx_fee: "500"
    }
  },
  payload: {
    type_id: TxPayloadTypeID.ContractCall,
    address: "SPNWZ5V2TPWGQGVDR6T7B6RQ4XMGZ4PXTEE0VQ0S",
    address_hash_bytes: "0x2bcf9762d5b90bc36dc1b4759b1727690f92ddd3",
    address_version: 22,
    contract_name: "marketplace-v4",
    function_name: "list-asset",
    function_args: [
      {
        type_id: ClarityTypeID.PrincipalContract,
        hex: "0x0616a6a7a70f41adbe8eae708ed7ec2cbf41a272182014626974636f696e2d6d6f6e6b6579732d6c616273",
        repr: "'SP2KAF9RF86PVX3NEE27DFV1CQX0T4WGR41X3S45C.bitcoin-monkeys-labs"
      },
      {
        type_id: ClarityTypeID.UInt,
        hex: "0x01000000000000000000000000000008ba",
        repr: "u2234"
      },
      {
        type_id: ClarityTypeID.UInt,
        hex: "0x010000000000000000000000000c845880",
        repr: "u210000000"
      },
      {
        type_id: ClarityTypeID.UInt,
        hex: "0x01000000000000000000000000000000c8",
        repr: "u200"
      }
    ],
    function_args_buffer: "0x000000040616a6a7a70f41adbe8eae708ed7ec2cbf41a272182014626974636f696e2d6d6f6e6b6579732d6c61627301000000000000000000000000000008ba010000000000000000000000000c84588001000000000000000000000000000000c8"
  },
  post_condition_mode: PostConditionModeID.Deny,
  post_conditions: [
    {
      condition_code: PostConditionNonfungibleConditionCodeID.Sent,
      condition_name: PostConditionNonFungibleConditionName.Sent,
      asset: {
        asset_name: "bitcoin-monkeys-labs",
        contract_address: "SP2KAF9RF86PVX3NEE27DFV1CQX0T4WGR41X3S45C",
        contract_name: "bitcoin-monkeys-labs"
      },
      asset_info_id: PostConditionAssetInfoID.NonfungibleAsset,
      asset_value: {
        hex: "0x01000000000000000000000000000008ba",
        repr: "u2234",
        type_id: ClarityTypeID.UInt
      },
      principal: {
        address: "SP24ZBZ8ZE6F48JE9G3F3HRTG9FK7E2H6K2QZ3Q1K",
        address_hash_bytes: "0x89f5fd1f719e4449c980de38e3504be6770a2698",
        address_version: 22,
        type_id: ClarityTypeID.Buffer
      }
    }
  ],
  post_conditions_buffer: "0x020000000102021689f5fd1f719e4449c980de38e3504be6770a269816a6a7a70f41adbe8eae708ed7ec2cbf41a272182014626974636f696e2d6d6f6e6b6579732d6c61627314626974636f696e2d6d6f6e6b6579732d6c61627301000000000000000000000000000008ba10"
});

Project Layout

The directory structure of this project is:

/
├── Cargo.toml    # The Cargo manifest file
├── package.json  # The npm manifest file
├── native/       # The Node addon modules built by this project, these are dynamically-linked shared objects
├── src/**/*.rs   # Directory containing the Rust source code for the project
|── index.ts      # Typescript definitions for the js interface exposed by the Node addon
|── loader.js     # Script to determine which addon file to load based on the executing target platform
|── loader.d.ts   # Type defintions for the functions exported by the Node addon
|── builder.js    # Script to build the native Node addon for the executing host platform
├── tests/*.ts    # Js/ts unit tests, primarily testing the Neon (rust<->nodejs) interop layer
└── perf-tests/   # Scripts to run performance benchmarks used by commands in package.json

The Rust source code inside the src/**/deserialize.rs files are responsible for deserializing the Stacks blockchain wire/binary formats defined in SIP-005.

NPM Library Bundling

The Node addon modules for all supported platforms are compiled by CI and bundled inside the npm package. The native binary files are small enough that the bundled npm package is an acceptable ~20 MB in size.

hirosystems/stacks-encoding-native-js

stacks-encoding-native-js

Runtime Support

Platform Support

Installation and Usage

Decoding serialized Clarity values

Decode serialized Clarity value to repr string

Decode serialized Clarity value to object

Decode serialized Clarity value to typed object

Decoding principals

Principal from serialized Clarity value

Stacks address from parts

Stacks address to parts

Decoding transactions

Project Layout

NPM Library Bundling