Chaindata

A community controlled index of networks, tokens and assets for the Polkadot, Ethereum and Solana ecosystems.

The goals of this repo are:

1. Provide a community-managed index of networks and their connection information (RPCs, genesis hashes, metadata)
2. Provide a source of network and token logos across the ecosystem
3. Publish this information as JSON files that any project can consume

Usage

The published files are consolidated JSON documents containing every network, token and Substrate miniMetadata:

• https://raw.githubusercontent.com/TalismanSociety/chaindata/main/pub/<version>/chaindata.json
• https://raw.githubusercontent.com/TalismanSociety/chaindata/main/pub/<version>/chaindata.min.json

<version> is the current pub version, v13 at the time of writing. It changes whenever the format of the published files breaks, see Chaindata pub versions below for the version list and how to find the latest one.

Their shape is { networks: Network[], tokens: Token[], miniMetadatas: MiniMetadata[] }. Types and Zod schemas for each object are exported by the @talismn/chaindata-provider package.

Talisman products consume these files through @talismn/chaindata-provider, which exposes a ChaindataProvider that keeps itself in sync with the published files. For a real-world example, see the Talisman Wallet source code, where the provider powers balance subscriptions and sending funds.

Logos are also served straight from this repo, e.g. https://raw.githubusercontent.com/TalismanSociety/chaindata/main/assets/tokens/dot.svg

Chaindata pub versions

Each pub/vN directory corresponds to a breaking change in the format of the published files. The version number is not stored in this repo: the build reads MINIMETADATA_VERSION from @talismn/chaindata-provider, so bumping that dependency is what moves the output to a new folder. The latest version is the highest pub/vN folder in this repo, or the MINIMETADATA_VERSION constant of the @talismn/chaindata-provider release you depend on.

Old directories are no longer rebuilt, but they are also never deleted. Wallet releases pinned to an older @talismn/chaindata-provider keep working with the last data built for their version.

Version	Since	Notes
v1-v3	2024-25	Legacy layout: one JSON file per chain/token/miniMetadata plus an index.txt
v4	2025-07	Single chaindata.json, refactored network and token objects, YAML input files
v5	2025-08	Solana networks and SPL tokens
v6-v9	2025-26	Incremental breaking changes to network, token and miniMetadata shapes
v10	2026-05
v11	2026-06
v12	2026-06
v13	2026-08	Current at the time of writing

How it works

Only the YAML files in data/ are edited by hand. Everything else is produced by three GitHub workflows that commit their output back to main:

Workflow	Trigger	Command	Output
Chaindata Validate	every push and PR	pnpm validate	Fails the PR if YAML formatting or schema validation fails
Chaindata Fetch External	every 6 hours, on main	pnpm fetch-external	data/cache, data/generated, mirrored logos in assets/
Chaindata Build	every push to main	pnpm build	pub/vN/chaindata.json and chaindata.min.json
Chaindata Fetch TAO Hotkey Logos	every 6 hours, on main	pnpm fetch-tao-hotkey-logos	assets/bittensor/hotkeys/

Fetch external

Pulls everything that needs network access or third-party data and caches it in the repo so that the build itself stays deterministic:

• Known EVM networks from chainlist, merged with data/networks-ethereum.yaml overrides
• RPC health checks for Polkadot and Ethereum networks (data/generated/rpc-health-*.json)
• Polkadot network specs (genesis hash, ss58 prefix, token decimals) and metadata extracts
• Solana network specs
• Token lists for each platform, resolved from on-chain data and the token configs in the YAML files
• Novasama metadata portal URLs, Vana VRC20 tokens, foreign assets fixes
• Coingecko token names and logos (assets/tokens/coingecko/), known EVM network logos (assets/chains/known/), Bittensor subnet logos (assets/tokens/dtao/)

Run a subset of steps with pnpm fetch-external --steps=checkPolkadotRpcs,fetchDotTokens (matching is case-insensitive and partial).

Build

Assembles the published files from the YAML configs and the cached external data, without hitting any RPC:

1. Networks for each platform
2. Tokens for each platform
3. Substrate miniMetadatas
4. Theme colors extracted from logos
5. Consolidated chaindata.json and chaindata.min.json, validated against the @talismn/chaindata-provider schemas

File structure

Path	Purpose
data/networks-polkadot.yaml	Relay chains, parachains and other Substrate networks, with their tokens
data/networks-ethereum.yaml	EVM networks, matched by id with chainlist; every field overrides the chainlist value
data/networks-solana.yaml	Solana networks and SPL tokens
data/coingecko-overrides.yaml	Overrides logos of some coingecko tokens
data/cache/	Generated by fetch-external, consumed by the build. Do not edit
data/generated/	Generated by fetch-external, kept for reference (rpc health, known EVM networks). Do not edit
schemas/	JSON schemas for the YAML files, generated from the Zod schemas in scripts/shared/schemas on pnpm install
assets/chains/	Network logos, named after the network id
assets/chains/known/	EVM network logos mirrored from chainlist. Do not edit
assets/tokens/	Token logos
assets/tokens/coingecko/	Token logos mirrored from coingecko. Do not edit
assets/tokens/dtao/	Bittensor subnet logos mirrored from chain. Do not edit
assets/bittensor/hotkeys/	Bittensor validator logos mirrored from chain. Do not edit
assets/promo/	Banner and card images used by Talisman products
pub/	Published output, one folder per format version
scripts/	Build, fetch-external and maintenance scripts
.papi/	polkadot-api descriptors used by the scripts

Contributing

Fork this repo, make your changes in your fork, then open a PR. Only edit the YAML files and the non-generated assets/ folders: JSON files and mirrored logos are regenerated by the CI and any manual change will be overwritten.

Add or update a Substrate network

Add an entry to data/networks-polkadot.yaml. Only id and rpcs are required, everything else (genesis hash, ss58 prefix, decimals, symbol) is fetched from the chain.

- id: my-network
  name: My Network
  isDefault: true
  nativeCurrency:
    coingeckoId: my-token
    logo: ./assets/tokens/my-token.svg
  logo: ./assets/chains/my-network.svg
  blockExplorerUrls:
    - https://my-network.subscan.io/
  rpcs:
    - wss://rpc.my-network.io

isDefault controls whether the network is enabled by default in Talisman Wallet.

Add or update an EVM network

Networks listed on chainlist are imported automatically. Add an entry to data/networks-ethereum.yaml only to enable a network by default, or to override chainlist data (name, RPCs, logo, explorer, fee type). Use the base-10 chain id (e.g. 1, or 137), not the base-16 id (e.g. 0x1, or 0x89).

Add or update a Solana network

Add an entry to data/networks-solana.yaml. Only id and rpcs are required, see the existing entries for the other fields.

Add tokens

Tokens are declared under the tokens key of their network, grouped by balance module:

Platform	Modules
Polkadot	substrate-native, substrate-assets, substrate-foreignassets, substrate-tokens, substrate-psp22, substrate-hydration, substrate-dtao
Ethereum	evm-erc20, evm-uniswapv2
Solana	sol-spl

Symbol, decimals and name are fetched from chain where possible, so most entries only need the on-chain identifier (asset id, contract address, mint address) and optionally a coingeckoId and a logo. Check existing entries in the YAML file for the fields expected by each module, or the JSON schemas in schemas/.

Add logos

• Network logos go in assets/chains/${id}.svg, where id is the network id from the YAML file (base-10 chain id for EVM networks)
• Token logos go in assets/tokens/${symbol}.svg, then set the logo property of the token entry to the relative path, e.g. ./assets/tokens/dot.svg
• Bittensor subnet logos are mirrored from the logo_url published on chain in each subnet identity (SubnetInfoRuntimeApi.get_all_dynamic_info) and take precedence over coingecko logos. To override one, set the logo property of the subnet entry in data/networks-polkadot.yaml
• Bittensor validator logos are mirrored from the image of each coldkey identity (SubtensorModule.IdentitiesV2). assets/bittensor/hotkeys/logos.json maps each delegate hotkey to its file

SVG is preferred, PNG and WebP are accepted.

Running locally

1. Enable pnpm via corepack with corepack enable
2. Clone the repo: git clone git@github.com:TalismanSociety/chaindata.git
3. Install the dependencies: pnpm install (this also generates the JSON schemas)
4. Copy .env.sample to .env and fill in the variables
5. Validate your changes: pnpm validate
6. Build the published files: pnpm build

The build embeds the current git branch name in logo URLs, so do not commit a pub/ folder built from a feature branch. The CI rebuilds pub/ after your PR is merged.

pnpm build:dev skips validation, and pnpm fetch-external refreshes the cached external data.