feat(sdk-coin-kas): add Kaspa (KAS) unique chain SDK integration by manojkumar138 · Pull Request #8421 · BitGo/BitGoJS

manojkumar138 · 2026-04-07T12:27:08Z

No description provided.

sachushaji · 2026-04-08T03:46:16Z

Copilot

Pull request overview

Adds first-party Kaspa (KAS) support across BitGoJS by introducing a new @bitgo/sdk-coin-kas package and wiring it into statics, BitGo coin registration, account-lib builders, and build/deploy plumbing.

Changes:

Added Kaspa statics (coin + networks) and registered kas / tkas in the global coin/token lists.
Introduced @bitgo/sdk-coin-kas with keypair, address utilities, transaction model, and builder (+ unit tests).
Integrated the new coin into BitGo/account-lib exports & registration, Docker build/link flow, and CODEOWNERS; renamed the existing ERC20 “kas” token to ekas to avoid symbol collision.

Reviewed changes

Copilot reviewed 41 out of 41 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
tsconfig.packages.json	Adds `sdk-coin-kas` TS project reference.
modules/statics/test/unit/fixtures/expectedColdFeatures.ts	Adds `kas` / `tkas` to expected cold features fixture.
modules/statics/src/networks.ts	Defines Kaspa network types and registers main/test networks.
modules/statics/src/kas.ts	Adds Kaspa statics coin factory/class.
modules/statics/src/index.ts	Exports `KASCoin` from statics.
modules/statics/src/coins/erc20Coins.ts	Renames ERC20 “kas” token to `ekas`.
modules/statics/src/base.ts	Adds `CoinFamily.KAS` and `BaseUnit.KAS`.
modules/statics/src/allCoinsAndTokens.ts	Registers `kas` and `tkas` in the global coin list.
modules/sdk-core/src/bitgo/environments.ts	Adds `kasNodeUrl` environment config and default URLs.
modules/sdk-coin-kas/tsconfig.json	New TS config for `@bitgo/sdk-coin-kas`.
modules/sdk-coin-kas/test/unit/utils.test.ts	Unit tests for Kaspa address/key utilities.
modules/sdk-coin-kas/test/unit/transactionFlow.test.ts	E2E flow test for build/sign/serialize/deserialize.
modules/sdk-coin-kas/test/unit/transactionBuilder.test.ts	Unit tests for transaction builder behavior.
modules/sdk-coin-kas/test/unit/transaction.test.ts	Unit tests for tx serialization, txid, sighash, explain.
modules/sdk-coin-kas/test/unit/keyPair.test.ts	Unit tests for keypair generation/validation/address derivation.
modules/sdk-coin-kas/test/unit/coin.test.ts	Unit tests for coin class surface behavior.
modules/sdk-coin-kas/test/fixtures/kas.fixtures.ts	Test vectors/fixtures for Kaspa tests.
modules/sdk-coin-kas/src/tkas.ts	Adds testnet coin class.
modules/sdk-coin-kas/src/register.ts	Adds SDK registration helper for `kas` / `tkas`.
modules/sdk-coin-kas/src/lib/utils.ts	Implements address encoding/decoding + serialization utils.
modules/sdk-coin-kas/src/lib/transactionBuilderFactory.ts	Adds builder factory for transfers/from-raw.
modules/sdk-coin-kas/src/lib/transactionBuilder.ts	Implements Kaspa UTXO transaction builder + signing.
modules/sdk-coin-kas/src/lib/transaction.ts	Implements tx model, serialization, txid, sighash.
modules/sdk-coin-kas/src/lib/keyPair.ts	Implements secp256k1 keypair and address derivation.
modules/sdk-coin-kas/src/lib/index.ts	Re-exports coin library primitives.
modules/sdk-coin-kas/src/lib/iface.ts	Adds Kaspa type definitions for tx/build/sign flows.
modules/sdk-coin-kas/src/lib/constants.ts	Adds Kaspa constants (HRPs, opcodes, fees, URLs, tags).
modules/sdk-coin-kas/src/kas.ts	Implements mainnet coin class (sign/explain/verify/etc).
modules/sdk-coin-kas/src/index.ts	Package entrypoint exports.
modules/sdk-coin-kas/package.json	New package manifest and dependencies.
modules/sdk-coin-kas/.mocharc.yml	Mocha config for running TS tests.
modules/sdk-coin-kas/.eslintignore	ESLint ignore list for the new module.
modules/bitgo/tsconfig.json	Adds `sdk-coin-kas` TS project reference.
modules/bitgo/src/v2/coins/index.ts	Exports Kaspa coin classes from BitGo v2 coins index.
modules/bitgo/src/v2/coinFactory.ts	Registers `kas` / `tkas` constructors in coin factory.
modules/bitgo/package.json	Adds `@bitgo/sdk-coin-kas` dependency.
modules/account-lib/tsconfig.json	Adds `sdk-coin-kas` TS project reference.
modules/account-lib/src/index.ts	Exposes Kaspa builders and adds to builder map.
modules/account-lib/package.json	Adds `@bitgo/sdk-coin-kas` dependency.
Dockerfile	Adds build/link steps for `sdk-coin-kas` in image.
CODEOWNERS	Adds code ownership for `modules/sdk-coin-kas/`.

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Copilot · 2026-04-09T07:25:41Z

modules/sdk-coin-kas/src/lib/utils.ts

+  const maxv = (1 << toBits) - 1;
+  for (const value of data) {
+    acc = (acc << fromBits) | value;
+    bits += fromBits;
+    while (bits >= toBits) {
+      bits -= toBits;
+      result.push((acc >> bits) & maxv);
+    }
+  }
+  if (pad && bits > 0) {
+    result.push((acc << (toBits - bits)) & maxv);
+  }


kaspaConvertBits uses bitwise shifts (<<, >>, |, &) on a JS number, which truncates to 32-bit signed integers. Since Kaspa address payloads are 32 bytes, the accumulator will overflow/wrap during encoding/decoding, producing non-standard addresses/checksums. Rework kaspaConvertBits to avoid 32-bit bitwise ops (e.g., use BigInt or arithmetic + masking like the standard convertbits implementation) and validate leftover bits when pad is false.

Suggested change

const maxv = (1 << toBits) - 1;

for (const value of data) {

acc = (acc << fromBits) | value;

bits += fromBits;

while (bits >= toBits) {

bits -= toBits;

result.push((acc >> bits) & maxv);

}

}

if (pad && bits > 0) {

result.push((acc << (toBits - bits)) & maxv);

}

const fromBase = 2 ** fromBits;

const toBase = 2 ** toBits;

const maxv = toBase - 1;

for (const value of data) {

if (!Number.isInteger(value) || value < 0 || value >= fromBase) {

throw new Error('Invalid value for kaspaConvertBits');

}

acc = acc * fromBase + value;

bits += fromBits;

while (bits >= toBits) {

bits -= toBits;

const divisor = 2 ** bits;

result.push(Math.floor(acc / divisor) % toBase);

acc = acc % divisor;

}

}

if (pad) {

if (bits > 0) {

result.push((acc * (2 ** (toBits - bits))) % toBase);

}

} else if (bits >= fromBits || acc * (2 ** (toBits - bits)) > maxv) {

throw new Error('Invalid incomplete group in kaspaConvertBits');

}

Copilot · 2026-04-09T07:25:41Z

modules/sdk-coin-kas/src/lib/utils.ts

+ * Kaspa (KAS) Utility Functions
+ *
+ * Address validation, encoding, script generation, and other utilities.
+ * Kaspa uses bech32m-encoded addresses with x-only secp256k1 public keys.


File header says Kaspa uses “bech32m-encoded addresses”, but this implementation is cashaddr-style with a hrp: separator (and later comments also say “not standard bech32/bech32m”). Please update the top-level documentation to match the actual encoding to avoid misleading integrators.

Suggested change

* Kaspa uses bech32m-encoded addresses with x-only secp256k1 public keys.

* Kaspa uses cashaddr-style addresses with an HRP and ':' separator, and

* x-only secp256k1 public keys.

Copilot · 2026-04-09T07:25:41Z

modules/sdk-coin-kas/src/lib/transactionBuilder.ts

+/**
+ * Extract x-only public key from address (for script building).
+ * Kaspa P2PK address payload IS the x-only public key.
+ */
+function addressToXOnlyPubKey(address: string): Buffer {
+  const { payload } = kaspaDecodeAddress(address);
+  return payload;
+}
+
+/**
+ * Build a P2PK script public key from an address.
+ */
+function addressToScriptPublicKey(address: string): KaspaScriptPublicKey {
+  const xOnlyPubKey = addressToXOnlyPubKey(address);
+  return buildScriptPublicKey(xOnlyPubKey);
+}


addressToScriptPublicKey always builds a P2PK locking script from the decoded payload, but isValidAddress allows both pubkey (0x00) and scripthash (0x08) address versions. For a scripthash address this would generate an invalid script and could burn funds. Either restrict builder outputs to pubkey addresses or branch on the decoded version and build the correct script for each address type.

Copilot · 2026-04-09T07:25:42Z

modules/sdk-coin-kas/src/lib/transactionBuilder.ts

+      const sig = secp256k1.sign(sighash, privKeyBytes, { lowS: false });
+      const sigBytes = Buffer.from(sig.toCompactRawBytes());


The code comments/state indicate Schnorr signatures, but the implementation uses secp256k1.sign(...) which is ECDSA in @noble/curves. Kaspa requires Schnorr signatures; use secp256k1.schnorr.sign(...) (or the correct Kaspa signing primitive) and ensure the produced signature format matches Kaspa’s script expectations.

Suggested change

const sig = secp256k1.sign(sighash, privKeyBytes, { lowS: false });

const sigBytes = Buffer.from(sig.toCompactRawBytes());

const sigBytes = Buffer.from(secp256k1.schnorr.sign(sighash, privKeyBytes));

Copilot · 2026-04-09T07:25:42Z

modules/sdk-coin-kas/src/kas.ts

+  async signTransaction(params: SignTransactionOptions): Promise<SignedTransaction> {
+    const kasParams = params as KaspaSignTransactionOptions;
+    const txHex = kasParams.txPrebuild?.txHex ?? kasParams.txPrebuild?.halfSigned?.txHex;
+    if (!txHex) {
+      throw new SigningError('Missing txHex in transaction prebuild');
+    }
+    if (!kasParams.prv) {
+      throw new SigningError('Missing private key');
+    }
+
+    const txBuilder = this.getBuilder().from(txHex);
+    txBuilder.sign({ key: kasParams.prv });
+    const tx = await txBuilder.build();
+
+    const signed = tx.toBroadcastFormat();
+    // Return halfSigned if only one signature (multisig), fully signed if complete
+    return tx.signature.length >= 2 ? { txHex: signed } : { halfSigned: { txHex: signed } };


signTransaction reconstructs the builder from txHex and immediately signs, but signing requires per-input UTXO data (utxoEntries) and that data is not serialized into txHex (and Transaction.deserialize doesn’t populate it). As written, txBuilder.sign() will throw for typical prebuilds. Update the prebuild/params to carry the input UTXOs (similar to other UTXO coins’ txPrebuild.txInfo.unspents) and inject them into the builder/transaction before computing sighashes.

Copilot · 2026-04-09T07:25:42Z

modules/sdk-coin-kas/package.json

+  "scripts": {
+    "build": "yarn tsc --build --incremental --verbose .",
+    "fmt": "prettier --write .",
+    "check-fmt": "prettier --check '**/*.{ts,js,json}'",
+    "clean": "rm -r ./dist",
+    "lint": "eslint --quiet .",
+    "prepare": "npm run build",
+    "test": "npm run coverage",
+    "coverage": "nyc -- npm run unit-test",
+    "unit-test": "mocha"
+  },


@bitgo/sdk-coin-kas’s tests rely on mocha+tsx (.mocharc.yml requires tsx) and other modules typically declare @bitgo/sdk-api / @bitgo/sdk-test (and sometimes tsx) in devDependencies. This package currently has an empty devDependencies, which can break standalone installs/tests/publishing. Align package.json devDependencies with the repo’s other sdk-coin-* packages.

Copilot · 2026-04-09T07:25:42Z

modules/sdk-coin-kas/test/unit/keyPair.test.ts

+  describe('getAddress', () => {
+    it('should derive a valid mainnet address', () => {
+      const kp = new KeyPair({ prv: validPrivateKey });
+      const address = kp.getAddress('mainnet');
+      address.should.startWith('kaspa:');
+      isValidAddress(address).should.be.true();
+    });
+
+    it('should derive a valid testnet address', () => {
+      const kp = new KeyPair({ prv: validPrivateKey });
+      const address = kp.getAddress('testnet');
+      address.should.startWith('kaspatest:');
+      isValidAddress(address).should.be.true();
+    });


Current KeyPair/address tests only assert prefix + isValidAddress(), which can pass even if the implementation is self-consistent but not spec-compliant. Add an assertion against known-good vectors (e.g., TEST_ACCOUNT.publicKey → TEST_ACCOUNT.mainnetAddress) to catch encoding/signing regressions.

Copilot · 2026-04-09T07:25:43Z

modules/statics/src/networks.ts

+/**
+ * Kaspa network interface.
+ * Kaspa is a UTXO-based BlockDAG using GHOSTDAG/Proof-of-Work with bech32m addresses.
+ */
+export interface KaspaNetwork extends BaseNetwork {
+  /** bech32m Human-Readable Part ('kaspa' for mainnet, 'kaspatest' for testnet) */
+  readonly hrp: string;
+}


Kaspa network docs here say “bech32m addresses”, but the SDK implementation uses cashaddr-style hrp: addresses. Please make the statics network documentation consistent with the actual address format used elsewhere in the PR.

mohd-kashif · 2026-04-09T07:52:44Z

modules/bitgo/src/v2/coins/index.ts

@@ -113,6 +114,7 @@ export { Etc, Tetc };
 export { EvmCoin, EthLikeErc20Token, EthLikeErc721Token };
 export { Flr, Tflr, FlrToken };
 export { Flrp };
+export { Kas, TKas };


TKas should be Tkas
this the naming convention followed for other coins

mohd-kashif · 2026-04-09T07:53:10Z

modules/bitgo/src/v2/coinFactory.ts

  Flr,
  Flrp,
+  Kas,
+  TKas,


mohd-kashif · 2026-04-09T07:54:05Z

modules/sdk-coin-kas/src/lib/constants.ts

+// RPC URLs (wRPC WebSocket)
+export const MAINNET_NODE_URL = 'wss://mainnet.kaspa.green';
+export const TESTNET_NODE_URL = 'wss://testnet-10.kaspa.green';
+
+// Explorer URLs
+export const MAINNET_EXPLORER_URL = 'https://explorer.kaspa.org/txs/';
+export const TESTNET_EXPLORER_URL = 'https://explorer-tn10.kaspa.org/txs/';


check if they can be picked from configs/statics

mohd-kashif · 2026-04-09T07:55:59Z

modules/sdk-coin-kas/src/lib/transaction.ts

+/** BLAKE2B output size (32 bytes) */
+const HASH_SIZE = 32;


this was in constant.ts, use from there

mohd-kashif · 2026-04-09T08:02:46Z

modules/sdk-coin-kas/src/tkas.ts

+import { BaseCoin as StaticsBaseCoin } from '@bitgo/statics';
+import { Kas } from './kas';
+
+export class TKas extends Kas {


mohd-kashif · 2026-04-09T08:08:35Z

modules/statics/src/coins/erc20Coins.ts

-    'kas',
-    'Kaspa',


this is a existing token, why changing this?

nvrakesh06 · 2026-04-09T08:15:59Z

modules/bitgo/src/v2/coins/index.ts

 import { EvmCoin, EthLikeErc20Token, EthLikeErc721Token } from '@bitgo/sdk-coin-evm';
 import { Flr, Tflr, FlrToken } from '@bitgo/sdk-coin-flr';
 import { Flrp } from '@bitgo/sdk-coin-flrp';
+import { Kas, TKas } from '@bitgo/sdk-coin-kas';


same for this as well. It needs to be Tkas

nvrakesh06 · 2026-04-09T08:16:25Z

modules/bitgo/src/v2/coinFactory.ts

  coinFactory.register('tfiatusd', TfiatUsd.createInstance);
  coinFactory.register('tflr', Tflr.createInstance);
  coinFactory.register('tflrp', Flrp.createInstance);
+  coinFactory.register('tkas', TKas.createInstance);


https://github.com/BitGo/BitGoJS/pull/8421/changes#r3056290720

nvrakesh06 · 2026-04-09T08:16:33Z

modules/bitgo/src/v2/coinFactory.ts

    case 'tflrp':
      return Flrp.createInstance;
+    case 'tkas':
+      return TKas.createInstance;


https://github.com/BitGo/BitGoJS/pull/8421/changes#r3056290720

nvrakesh06 · 2026-04-09T08:29:58Z

modules/sdk-coin-kas/src/kas.ts

+  async signMessage(key: BaseKeyPair, message: string | Buffer): Promise<Buffer> {
+    throw new MethodNotImplementedError();
+  }
+
+  /** @inheritdoc */
+  auditDecryptedKey(params: AuditDecryptedKeyParams): void {
+    throw new MethodNotImplementedError();
+  }


Let's not throw an error for non implemented methods rather just return it.
It is avoid any issues with TAT that we faced in the past.

nvrakesh06 · 2026-04-09T08:30:32Z

modules/sdk-coin-kas/src/kas.ts

+    try {
+      new KeyPair({ pub });
+      return true;
+    } catch {
+      return false;
+    }


move to utils

nvrakesh06 · 2026-04-09T08:30:43Z

modules/sdk-coin-kas/src/kas.ts

+    try {
+      new KeyPair({ prv });
+      return true;
+    } catch {
+      return false;
+    }


https://github.com/BitGo/BitGoJS/pull/8421/changes#r3056486237

…HO-388] Implements a full BitGoJS SDK module for Kaspa (KAS), a UTXO-based BlockDAG chain using Schnorr signatures over secp256k1 and BLAKE2B sighash with the "TransactionSigningHash" domain tag. Changes: - modules/sdk-coin-kas/: new SDK module with KeyPair, Transaction, TransactionBuilder, TransactionBuilderFactory, Kas/TKas coin classes, constants, interfaces, and utilities - Kaspa cashaddr encoding (`:` separator, custom polymod checksum) - statics: KasCoin class, CoinFamily.KAS, BaseUnit.KAS, KaspaMainnet/ KaspaTestnet networks, kas/tkas coin entries with UUIDs - sdk-core/environments.ts: kasNodeUrl field - bitgo/coinFactory.ts + coins/index.ts: kas/tkas registered - account-lib: kas/tkas added to coinBuilderMap - tsconfig references updated (account-lib, bitgo, tsconfig.packages.json) - CODEOWNERS, Dockerfile updated Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

manojkumar138 requested review from a team as code owners April 7, 2026 12:27

manojkumar138 requested review from Marzooqa and mrdanish26 April 7, 2026 12:27

mohd-kashif marked this pull request as draft April 8, 2026 05:20

manojkumar138 force-pushed the feat/kaspa-sdk branch 2 times, most recently from 00809c6 to 4e4bc10 Compare April 8, 2026 07:32

mohd-kashif force-pushed the feat/kaspa-sdk branch from 4e4bc10 to 5e47526 Compare April 8, 2026 17:06

mohd-kashif marked this pull request as ready for review April 9, 2026 07:17

mohd-kashif requested a review from Copilot April 9, 2026 07:17

Copilot started reviewing on behalf of mohd-kashif April 9, 2026 07:18 View session

Copilot AI reviewed Apr 9, 2026

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mohd-kashif requested changes Apr 9, 2026

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nvrakesh06 reviewed Apr 9, 2026

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manojkumar138 force-pushed the feat/kaspa-sdk branch 4 times, most recently from f1da067 to f9e9eb2 Compare April 10, 2026 09:37

manojkumar138 force-pushed the feat/kaspa-sdk branch from f9e9eb2 to 6dca045 Compare April 10, 2026 10:41

-  const maxv = (1 << toBits) - 1;
-  for (const value of data) {
-    acc = (acc << fromBits) | value;
-    bits += fromBits;
-    while (bits >= toBits) {
-      bits -= toBits;
-      result.push((acc >> bits) & maxv);
-    }
-  }
-  if (pad && bits > 0) {
-    result.push((acc << (toBits - bits)) & maxv);
-  }
+  const fromBase = 2 ** fromBits;
+  const toBase = 2 ** toBits;
+  const maxv = toBase - 1;
+  for (const value of data) {
+    if (!Number.isInteger(value) || value < 0 || value >= fromBase) {
+      throw new Error('Invalid value for kaspaConvertBits');
+    }
+    acc = acc * fromBase + value;
+    bits += fromBits;
+    while (bits >= toBits) {
+      bits -= toBits;
+      const divisor = 2 ** bits;
+      result.push(Math.floor(acc / divisor) % toBase);
+      acc = acc % divisor;
+    }
+  }
+  if (pad) {
+    if (bits > 0) {
+      result.push((acc * (2 ** (toBits - bits))) % toBase);
+    }
+  } else if (bits >= fromBits || acc * (2 ** (toBits - bits)) > maxv) {
+    throw new Error('Invalid incomplete group in kaspaConvertBits');
+  }

	* Kaspa uses bech32m-encoded addresses with x-only secp256k1 public keys.
	* Kaspa uses cashaddr-style addresses with an HRP and ':' separator, and
	* x-only secp256k1 public keys.

		const sig = secp256k1.sign(sighash, privKeyBytes, { lowS: false });
		const sigBytes = Buffer.from(sig.toCompactRawBytes());

	const sig = secp256k1.sign(sighash, privKeyBytes, { lowS: false });
	const sigBytes = Buffer.from(sig.toCompactRawBytes());
	const sigBytes = Buffer.from(secp256k1.schnorr.sign(sighash, privKeyBytes));

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manojkumar138 commented Apr 7, 2026

Uh oh!

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