@avalabs/crypto-wasm

WebAssembly build of @avalabs/crypto-core. Ships:

• dist/index.{js,cjs,d.ts,d.cts} — thin TypeScript wrapper exposing the pubkey-only public surface documented under API below.
• dist/crypto.js — Emscripten loader with the WASM binary base64- inlined inside it (single artifact, MV3 extension-safe). When built with CRYPTO_WASM_SINGLE_FILE=OFF, also emits dist/crypto.wasm next to it for web-app builds that prefer streaming compile + a smaller bundle.

Most callers should depend on @avalabs/crypto-sdk instead — it routes to this package on web / extension / Node (via the browser / import exports conditions) and to @avalabs/crypto-nitro on React Native. The direct exports on this package carry @deprecated JSDoc hints to nudge consumers toward the unified entry point.

Build prerequisites

The build needs Emscripten (emcc, emcmake, emmake) on $PATH. libsecp256k1 is vendored on demand into packages-internal/crypto-core/deps/secp256k1 by scripts/build-wasm.sh — no separate setup step needed for a clean checkout.

# One-time emsdk setup (if not already installed)
~/emsdk/emsdk install latest
~/emsdk/emsdk activate latest
source ~/emsdk/emsdk_env.sh

Build

pnpm --filter @avalabs/crypto-wasm run build

Runs the TypeScript wrapper build (tsdown) and the WASM build (scripts/build-wasm.sh). The WASM build:

1. Sources ~/emsdk/emsdk_env.sh if EMSDK isn't already exported.
2. Vendors libsecp256k1 into packages-internal/crypto-core/deps/secp256k1 if missing.
3. emcmake cmake against CMakeLists.txt, which transitively includes packages-internal/crypto-core/CMakeLists.txt.
4. emmake make -j compiles the artifacts.
5. Copies them into dist/ (and into src/ so tsdown can resolve import createCryptoModule from './crypto.js' at TypeScript-bundle time).

Override the artifact mode with:

CRYPTO_WASM_SINGLE_FILE=OFF pnpm --filter @avalabs/crypto-wasm run build:wasm

API

ℹ️ Most consumers should import these from @avalabs/crypto-sdk — same signatures, but the SDK picks the right backend (nitro on React Native, this package elsewhere) at bundle time. The direct exports below carry @deprecated JSDoc tags.

import {
  init,
  deriveAddressesFromXpubs,
  deriveAddressesForEvm,
  deriveAddressesForSvm,
  deriveAddressesForBtc,
  deriveAddressesForAvalanche,
  MAX_BATCH_SIZE,
  type DerivedSecp256k1Addresses,
  type DerivedAvalancheAddresses,
} from '@avalabs/crypto-wasm';

// 1. Load the WASM module. Required once before any derive*() call.
//    Idempotent — repeated invocations re-use the cached promise.
await init();

// 2. Xpub-driven batch derivation (Ledger / watch-only flow).
//    `avalancheXpubs[i]` and `accountIndices[i]` pair up.
const rows: DerivedSecp256k1Addresses[] = await deriveAddressesFromXpubs(
  'xpub...',                  // EVM xpub at m/44'/60'/0'
  ['xpub...', 'xpub...'],     // Avalanche xpubs (one per account)
  false,                      // isTestnet
  [0, 1],                     // account indices
);
// rows[i] === { accountIndex, evm, btc, avm, pvm, coreEth }

// 3. Per-chain encoders for batches of already-derived pubkeys.
//    Each accepts Uint8Array | ArrayBuffer per element; the wrapper
//    takes a tight copy at the boundary, so slices of a larger buffer
//    work correctly.
const evmAddrs = await deriveAddressesForEvm(compressedSecp256k1PubKeys33);
const btcAddrs = await deriveAddressesForBtc(compressedSecp256k1PubKeys33, false);
const svmAddrs = await deriveAddressesForSvm(ed25519PubKeys32);
const avaxBundles: DerivedAvalancheAddresses[] =
  await deriveAddressesForAvalanche(
    compressedAvaxPubKeys33,   // drives X- / P-
    compressedEvmPubKeys33,    // drives C-
    false,                     // isTestnet
  );
// avaxBundles[i] === { x, p, coreEth }

// Hard upper bound on items per batch (currently 1024). Re-exported so
// callers can chunk deterministically instead of catching `RangeError`.
console.log(MAX_BATCH_SIZE);

What's not in the surface here

signSchnorr, verifySchnorr, sign, verify, getPublicKey*, getExtendedPublicKey, and pointAddScalar currently exist only in @avalabs/crypto-nitro. Adding them here is a follow-up — track via the crypto-wasm milestone.