Frontier is the EVM backbone of Polkadot.

Frontier provides a compatibility layer of EVM, so that you can run any Ethereum dapps on Polkadot, unmodified. Using Frontier, you get access to all the Ethereum RPC APIs you are already familiar with, and therefore you can continue to develop your dapps in your favourite Ethereum developer tools. As a bonus, you can even run many Ethereum L2s inside Frontier! For those looking to become acquainted with Frontier, consult the documentation provided here. Additionally, a template node is available to facilitate a more comprehensive technical exploration.

Frontier is also a migration framework. Besides the common strategy of direct state export/import and transaction-level replays, Frontier's Pre-Log Wrapper Block feature provides a possible method for a zero-downtime live migration.

All changes (except new releases) are handled through pull requests.

Frontier follows Semantic Versioning. An unreleased crate in the repository will have the -dev suffix in the end, and we do rolling releases.

When you make a pull request against this repository, please also update the affected crates' versions, using the following rules. Note that the rules should be applied recursively -- if a change modifies any upper crate's dependency (even just the Cargo.toml file), then the upper crate will also need to apply those rules.

Additionally, if your change is notable, then you should also modify the corresponding CHANGELOG.md file, in the "Unreleased" section.

If the affected crate already has -dev suffix:

• If your change is a patch, then you do not have to update any versions.
• If your change introduces a new feature, please check if the local version already had its minor version bumped, if not, bump it.
• If your change modifies the current interface, please check if the local version already had its major version bumped, if not, bump it.

If the affected crate does not yet have -dev suffix:

• If your change is a patch, then bump the patch version, and add -dev suffix.
• If your change introduces a new feature, then bump the minor version, and add -dev suffix.
• If your change modifies the current interface, then bump the major version, and add -dev suffix.

If your pull request introduces a new crate, please set its version to 1.0.0-dev.