Chaindata

A community controlled repository of relay and parachain information in the Polkadot ecosystem.

The goals of this repo are:

1. Provide a community-managed index of Polkadot parachains and their connection information (rpcs, chainspecs)
2. Provide a source of chain and token assets across the ecosystem
3. Enable developers to retrieve this information via an API suitable to their project (json/rest, npm soon™)
4. Move towards a decentralised model

Usage

The files in this repo, data/chaindata.json, data/testnets-chaindata.json and data/evm-networks.json are used to configure a GitHub workflow which scrapes information from each chain and publishes it as a collection of JSON files in the pub directory of this repo.

The published files can be downloaded at these URLs:

• https://raw.githubusercontent.com/TalismanSociety/chaindata/main/pub/v4/chaindata.json
• https://raw.githubusercontent.com/TalismanSociety/chaindata/main/pub/v4/chaindata.min.json

They are used by Talisman products via the @talismn/chaindata-provider library, which provides a ChaindataProvider that automatically synchronizes with these files to expose chains and tokens, alongside with typings and utilities.

For an example of a more advanced use-case, you can check out the source code for Talisman Wallet.
The wallet uses our ChaindataProvider for features like account balance subscriptions and sending funds.

Chaindata pub versions

When breaking changes are made to the format of the built chaindata files, we increment the pub directory version.

Old directories are generally not kept up-to-date, but they are also not deleted.

The effect of this is that newer @talismn/balances releases will target the newer pub version, while older releases will continue to operate with the most up-to-date chaindata before the breaking change occurred.

A brief rundown of the changes introduced by each pub version:

• dist -> pub/v1
  The miniMetadatas for the substrate-native balance module now include types for Balances::Holds and Balances::Locks.
  Without upgrading @talismn/balances, these new types cause PortableRegistry to throw on construction of a new Metadata(miniMetadata).

• pub/v1 -> pub/v2
  All miniMetadatas have been upgraded from metadata format v14 to v15.
  Without upgrading @talismn/balances, the new format causes the library to throw.

• pub/v2 -> pub/v3
  Changed how some token ids are generated.

• pub/v4 -> pub/v4
  Refactored network and token objects. YAML input files.

Contributing

To make a contribution, please fork this repo and make your changes in your fork, then open a PR to merge your changes back into this repo.

To add chain or token logos:

Substrate chain logos

1. Identify the chain id from networks-polkadot.yaml
2. Add your logo (in svg format) to assets/chains/${id}.svg

EVM chain logos

1. Identify the chain id from https://chainlist.org
   Use the base-10 id (e.g. 1, or 137), not the base-16 id (e.g. 0x1, or 0x89)
2. Add your logo (in svg format) to assets/chains/${id}.svg

Token logos

1. Add your logo (in svg format) to assets/tokens/${symbol}.svg
2. In networks-polkadot.yaml find the logo entry and set the logo property with the relative path of the token.

To build the pub directory locally:

1. Install pnpm via corepack by running corepack enable on the command line
2. Clone the repo with
   git clone git@github.com:TalismanSociety/chaindata.git
3. Install the dependencies with
   pnpm install
4. Copy .env.sample to .env and fill in the variables
5. Run the build with
   pnpm build

File structure

Only YAML files may be edited manually, JSON files are generated automatically as part of the CI.

The table below describes the purpose of each editable file.

File name	Purpose
data/networks-polkadot.yaml	A list of all parachains and relay chains in the Polkadot ecosystem
data/networks-ethereum.json	List of Ethereum networks that are marked isDefault: true in Talisman
`data/ethereum-known-networks-overrides.yaml	Overrides to ethereum-lists, matched by id
data/coingecko-overrides.yaml	Overrides logos of some coingecko tokens

Dev Resources

Sections needing improvement

There are a few sections in this repo which could do with a tidy up.
Here is a list of some of them, feel free to add more!

• The code for merging known-evm-networks.json with data/networks-ethereum.json is complex, stateful, full of side-effects and therefore difficult to re-use between the build stage and the fetch-external stage.
  It is currently co-located inside of scripts/build/steps/addEvmNetworks.ts.
  We should decide on a simpler mechanism for merging these two files, and extract the implementation of that into a util file.
  An example of where this currently fails is in scripts/fetch-external/steps/fetchErc20TokenSymbols.ts.
  In here we append the two files like so const allNetworks = knownEvmNetworks.concat(evmNetworks), which results in duplicate networks in the allNetworks list.
  This makes it difficult to e.g. extract a coingeckoId for a given erc20 contract address on a given network, since the code using allNetworks needs to account for duplicate networks with potentially conflicting information.

• Currently all of the EVM tokens are hydrated from known-tokens, while all substrate tokens are hydrated from tokens.json.
  This is counter-intuitive, and so it leads to questions like "Why can I only see substrate tokens on chaindata? Are the EVM tokens missing / broken?"
  We should either consolidate the two lists of tokens in one place, or change the naming used to clarify that not all tokens can be found in one place.

Query the top 100 (by TVL) Uniswap V2 pool addresses

curl 'https://interface.gateway.uniswap.org/v1/graphql' \
-X 'POST' \
-H 'Content-Type: application/json' \
-H 'Origin: https://app.uniswap.org' \
--data-binary '{"operationName":"TopV2Pairs","variables":{"first":100,"chain":"ETHEREUM"},"query":"query TopV2Pairs($chain: Chain!, $first: Int!, $cursor: Float, $tokenAddress: String) {\n  topV2Pairs(\n    first: $first\n    chain: $chain\n    tokenFilter: $tokenAddress\n    tvlCursor: $cursor\n  ) {\n    protocolVersion\n    address\n  }\n}"}'

Possible values for chain when this was written:

ARBITRUM, AVALANCHE, ETHEREUM, ETHEREUM_GOERLI, ETHEREUM_SEPOLIA, OPTIMISM, POLYGON, CELO, BNB, BASE, BLAST