walletOS Sandbox is Now Available

walletOS Sandbox is Now Available

Making blockchains usable is our mission at Pine Street Labs.

Each new blockchain introduces unique transaction lifecycles, encoding schemes, consensus engines, architectures, and more. Technical variance across the ecosystem has made it difficult and expensive for wallet developers to build and maintain necessary tooling to interact with the growing multichain world.

We spent most of 2022 creating and developing walletOS, an API for using blockchains. walletOS provides developers with a single interface to generate addresses, build transactions, fetch data, and broadcast transactions across 18 blockchains and counting.

Today, we are excited to announce that walletOS Sandbox, a testnet environment to use the API, is now available for free.  

Read the docs and get started today:


  • walletOS Sandbox is now publicly available for free
  • Support 18+ blockchains into your wallet with a single API
  • Be in complete control of the UX for your product
  • Easily embed staking and smart contracts with simple endpoints

Integrate many blockchains with one API

Supporting a new blockchain previously required building in-house wallet libraries with custom integrations and bespoke logic. Between the research, personnel, development, and ongoing maintenance required to build wallet libraries, this could take months of engineering time.

walletOS eliminates this work and replaces it with a simple, one time integration of a single component. What does this mean for wallet developers? It means that you can now integrate 18+ blockchains into your product with a few lines of code and get to market faster.

An example request to transfer NEAR using walletOS

What Do I Get with walletOS?

  • 18+ blockchains out of the box: Generate single signature and multisig addresses, build transactions, fetch data, and broadcast transactions.
  • Automatic Transaction Input Collection: walletOS automatically and dynamically fetches relevant auxiliary data (e.g. nonce, coin selection, gas fees, etc) for the transaction you want to send, regardless of the network. Developers only need to provide business logic to walletOS and we take care of the rest.
  • Fetch Relevant Data: Access account balances, track transaction confirmations, get notified about deposits, and obtain chain state through API calls.
  • Built in Security: walletOS automatically validates addresses and decodes transactions to ensure your operations are valid and you know exactly what is going to happen before you broadcast.
  • Intuitive Endpoints: walletOS eliminates the need to understand a glossary worth of crypto specific jargon with intuitive endpoints that describe your desired action.

Staking and Smart Contracts

walletOS provides you with the ability to integrate staking and smart contract interaction into your product.

Staking and Delegating

There are many infrastructure providers today who run nodes, but there can be friction for wallet developers when it comes to communicating to the blockchain that a given token is being staked/delegated with a particular validator.

walletOS automatically generates these transactions for developers with our create_validator, delegate, and undelegate endpoints. create_validator makes it easy to register a new validator on a Proof of Stake blockchain while delegate and undelegate facilitate delegations on certain PoS networks.

An example request to delegate on the Avalanche P Chain using walletOS

walletOS supports staking for Etheruem, Solana, Avalanche, Cosmos, NEAR, Osmosis, Axelar, and more.

Smart Contracts

Access token standards and DeFi using walletOS. Developers can integrate ERC20 token and SPL token support out of the box by using the API.  

Our swap endpoint is currently in beta and will be available to users in the coming weeks. Once it’s made available, users will be able to swap ERC20 tokens using Uniswap on Ethereum, Polygon, Arbitrum, Optimism, and Avalanche’s C-Chain (once Uniswap has deployed).

An example request to swap ERC20 tokens on Ethereum using walletOS

Customize Your walletOS Instance

walletOS is designed for developers building wallet products. We know first hand that wallets come in many different variations, from the way that transactions are signed to the UI. With this in mind, we built walletOS to be as flexible as possible.

When using walletOS, developers can customize:

  • DeploymentwalletOS can run on premises or access via the cloud
  • UX and Front End walletOS is middleware, it is infrastructure as an API. Users stay in complete control of UI and UX.
  • NodeswalletOS provides interfaces to popular RPC nodes. You can elect to use walletOS with your own node infrastructure, otherwise, users can rely on our node infrastructure for easy broadcasting.

Get Started

Visit our website to learn more. Access our documentation and sign up for the Sandbox to get your API key and get started.

If you want to learn more about walletOS and use it in production, book a demo today and we will get in touch shortly. You can book a demo here.

We can’t wait to see what you build!