@anywalletkit/runtime-hermes

@anywalletkit/runtime-hermes

One call, at the app entry, after react-native-get-random-values, buffer and a TextEncoder polyfill are in place:

Install

npm install @anywalletkit/runtime-hermes buffer fastestsmallesttextencoderdecoder react-native-url-polyfill
# or: pnpm add @anywalletkit/runtime-hermes buffer fastestsmallesttextencoderdecoder react-native-url-polyfill  ·  yarn add @anywalletkit/runtime-hermes buffer fastestsmallesttextencoderdecoder react-native-url-polyfill

On npm: @anywalletkit/runtime-hermes, published from the release workflow with provenance. React Native / Hermes only; import it first in your entry file.

import 'react-native-get-random-values'
import { Buffer } from 'buffer'
global.Buffer ??= Buffer
import 'fastestsmallesttextencoderdecoder/EncoderDecoderTogether.min.js'
import 'react-native-url-polyfill/auto'
import { installHermesRuntime } from '@anywalletkit/runtime-hermes'
installHermesRuntime()

What it installs, each only when missing:

	why
Buffer.prototype.subarray keeps the Buffer prototype	Hermes has no Symbol.species; @ton/core, bitcoinjs-lib and other Node-style libraries call .copy() / .readUInt32BE() on sliced Buffers
AbortSignal.timeout / AbortSignal.any	missing on Hermes; their absence silently broke every cross-chain swap execution once
crypto.subtle.digest (SHA-256/384/512 via noble)	the Solana ed25519 polyfill creates subtle without digest
structuredClone	missing on older Hermes

It throws when the things only the app can provide are absent: crypto.getRandomValues, TextEncoder/TextDecoder, and a full WHATWG URL (React Native’s built-in one has no working searchParams; providers parse endpoints and query strings with it). SDK packages never import this package themselves.

Metro: react-native-fast-pbkdf2

@anywalletkit/wallet-ton pulls in @ton/crypto-primitives, whose React Native build requires the native react-native-fast-pbkdf2 module (TON 24-word mnemonics) and expo-crypto. Install expo-crypto, and point Metro at the pure-JS drop-in this package ships instead of the native module:

metro.config.js

const { getDefaultConfig } = require('expo/metro-config')
const config = getDefaultConfig(__dirname)
const resolveRequest = config.resolver.resolveRequest
config.resolver.resolveRequest = (context, moduleName, platform) =>
  moduleName === 'react-native-fast-pbkdf2'
    ? { type: 'sourceFile', filePath: require.resolve('@anywalletkit/runtime-hermes/fast-pbkdf2') }
    : (resolveRequest ?? context.resolveRequest)(context, moduleName, platform)
module.exports = config

Same call shape as the native module (base64 in, base64 out), PBKDF2 from @noble/hashes.

Interfaces

• HermesRuntimeReport

Functions

• installAbortSignalAny
• installAbortSignalTimeout
• installBufferSubarrayFix
• installHermesRuntime
• installSecureContext
• installStructuredClone
• installSubtleDigest
• probeUrl