# EVM Playground

## About

Humanode network is an EVM-compatible chain. You are able to use Humanode network as usual EVM-based chain in the way of holding and transferring tokens, creating and calling smart contracts, using Ethereum RPC API, using external EVM tools like Metamask to hold funds, Remix IDE and Truffle software to develop your smart contracts. The main difference is that you can't run a validator node and participate in consensus logic in terms of EVM terminology. 

Check the Ethereum compatibility doc for details.

{% content-ref url="/pages/bv9XoT02S3V4xpAgE5g1" %}
[EVM Compatibility](/docs/evm/evm-compatibility.md)
{% endcontent-ref %}

## HMND/eHMND swap

The EVM playground currently provides just a single tool: HMND/eHMND currency swap.

This is a UI for the [HMND/eHMND swap](/docs/evm/hmnd-ehmnd-swap.md) functionality we have on our chain. It allows you to send your HMND to an EVM account as eHMND, or send eHMND from an EVM account to a native account.

The conversion cost is close to the usual transfer, and the cost only consists of the transaction fee - there is no charge for the conversion itself.

The UI is pretty intuitive; you need a native wallet (i.e. [Polkadot.js extension](/docs/tools-and-services/polkadotjs-extension.md)) to send the HMND from the native account, and an EVM wallet (i.e. MetaMask, or others) to send the eHMND from the EVM account.

## EVM accounts mapping

{% hint style="warning" %}
As of Testnet 5 this account mappings mechanism is obsolete.
{% endhint %}

Humanode Network allows two account kinds:

* Substrate Accounts and
* Ethereum Accounts.

By default, substrate account doesn't match any ethereum account that can be represented as the same account (substrate and ethereum accounts systems use different cryptographic algorithms). 

But you can create a permanent two-way binding between an ethereum account and a native substrate account with `claim_account` extrinsic.

To simplify manual process of creating and submitting `claim_account` extrinsic, Humanode provides EVM Accounts mapping tool that connects to your Polkados.js and Metamask extensions where you can chose the accounts itself that will be mapped, creates and signs `claim_account` extrinsic and submits it to the network. 

{% content-ref url="/pages/cSXr15XlOQO5wr97rA0g" %}
[Chains](/docs/chains.md)
{% endcontent-ref %}


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