Vincent Geddes
22d5b80d44
Bridging fees are calculated using a static ETH/DOT exchange rate that can deviate significantly from the real-world exchange rate. We therefore need to add a safety margin to the fee so that users almost aways cover the cost of relaying. # FAQ > Why introduce a `multiplier` parameter instead of configuring an exchange rate which already has a safety factor applied? When converting from ETH to DOT, we need to _divide_ the multiplier by the exchange rate, and to convert from DOT to ETH we need to _multiply_ the multiplier by the exchange rate. > Other input parameters to the fee calculation can also deviate from real-world values. These include substrate weights, gas prices, and so on. Why does the multiplier introduced here not adjust those? A single scalar multiplier won't be able to accommodate the different volatilities efficiently. For example, gas prices are much more volatile than exchange rates, and substrate weights hardly ever change. So the pricing config relating to weights and gas prices should already have some appropriate safety margin pre-applied. # Detailed Changes: * Added `multiplier` field to `PricingParameters` * Outbound-queue fee is multiplied by `multiplier` * This `multiplier` is synced to the Ethereum side * Improved Runtime API for calculating outbound-queue fees. This API makes it much easier to for configure parts of the system in preparation for launch. * Improve and clarify code documentation Upstreamed from https://github.com/Snowfork/polkadot-sdk/pull/127 --------- Co-authored-by: Clara van Staden <claravanstaden64@gmail.com> Co-authored-by: Adrian Catangiu <adrian@parity.io>
Snowbridge ·
Snowbridge is a trustless bridge between Polkadot and Ethereum. For documentation, visit https://docs.snowbridge.network.
Components
The Snowbridge project lives in two repositories:
- Snowfork/Polkadot-sdk: The Snowbridge parachain and pallets live in a fork of the Polkadot SDK. Changes are eventually contributed back to paritytech/Polkadot-sdk
- Snowfork/snowbridge: The rest of the Snowbridge components, like contracts, off-chain relayer, end-to-end tests and test-net setup code.
Parachain
Polkadot parachain and our pallets. See README.md.
Contracts
Ethereum contracts and unit tests. See Snowfork/snowbridge/contracts/README.md
Relayer
Off-chain relayer services for relaying messages between Polkadot and Ethereum. See Snowfork/snowbridge/relayer/README.md
Local Testnet
Scripts to provision a local testnet, running the above services to bridge between local deployments of Polkadot and Ethereum. See Snowfork/snowbridge/web/packages/test/README.md.
Smoke Tests
Integration tests for our local testnet. See Snowfork/snowbridge/smoketest/README.md.
Development
We use the Nix package manager to provide a reproducible and maintainable developer environment.
After installing nix Nix, enable flakes:
mkdir -p ~/.config/nix
echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf
Then activate a developer shell in the root of our repo, where
flake.nix is located:
nix develop
Also make sure to run this initialization script once:
scripts/init.sh
Support for code editors
To ensure your code editor (such as VS Code) can execute tools in the nix shell, startup your editor within the interactive shell.
Example for VS Code:
nix develop
code .
Custom shells
The developer shell is bash by default. To preserve your existing shell:
nix develop --command $SHELL
Automatic developer shells
To automatically enter the developer shell whenever you open the project, install
direnv and use the template .envrc:
cp .envrc.example .envrc
direnv allow
Upgrading the Rust toolchain
Sometimes we would like to upgrade rust toolchain. First update rust-toolchain.toml as required and then
update flake.lock running
nix flake lock --update-input rust-overlay
Troubleshooting
Check the contents of all .envrc files.
Remove untracked files:
git clean -idx
Ensure that the current Rust toolchain is the one selected in scripts/init.sh.
Ensure submodules are up-to-date:
git submodule update
Check untracked files & directories:
git clean -ndx | awk '{print $3}'
After removing node_modules directories (eg. with git clean above), clear the pnpm cache:
pnpm store prune
Check Nix config in ~/.config/nix/nix.conf.
Run a pure developer shell (note that this removes access to your local tools):
nix develop -i --pure-eval
Security
The security policy and procedures can be found in SECURITY.md.