Chains API

Retrieve a list of supported chains and their associated metadata.

The Blocknative Chains API provides metadata on supported chains, including their chain ID, label, architecture, and available features. This allows developers to dynamically identify which networks are integrated with Blocknative services.

Authentication

A valid Blocknative API key is OPTIONAL in the Authorization Header of every request. Request an API key here.

A free API key is recommended for more generous rate limits and future features.

API Endpoint

GET https://api.blocknative.com/chains

Returns a list of supported chains along with their chain ID, label, architecture (e.g., evm), and available features (e.g., blockprices). This allows users to identify networks where Blocknative provides gas price estimation and related services. The list and available fields are subject to change as new chains or parameters are added or updated.

Rate Limits

Each endpoint is limited to provide updated results once per second for paid tier API keys, or every 5 seconds for free tier API keys. Polling faster than these rates may deliver stale data.

Example Request

curl -H 'Authorization: optional-apikey-here'
     'https://api.blocknative.com/chains'

Headers

Name	Type	Description
Authorization	String	OPTIONAL if used, must contain a valid apikey

Response Codes

Code	Description
200	Success
401	API key invalid or not provided
429	Rate limit exceeded. Refer to headers for retry

Example Response

[
  {
    "arch": "evm",
    "chainId": 1,
    "label": "Ethereum",
    "features": ["blockprices", "recentblocks", "distribution"],
    "icon": "https://bnc-assets.com/evm/1/assets/icon.svg",
    "system": "ethereum",
    "network": "mainnet"
  },
  {
    "arch": "evm",
    "chainId": 137,
    "label": "Polygon",
    "features": ["blockprices"],
    "icon": "https://bnc-assets.com/evm/137/assets/icon.svg",
    "system": "ethereum",
    "network": "mainnet"
  },
  {
    "arch": "evm",
    "chainId": 8453,
    "label": "Base",
    "features": ["blockprices"],
    "icon": "https://bnc-assets.com/evm/8453/assets/icon.svg",
    "system": "ethereum",
    "network": "mainnet"
  }
]

Response Fields

Field	Type	Description
arch	String	The blockchain architecture (e.g., "evm").
chainId	Integer	The unique identifier for the blockchain (e.g., 1 for Ethereum).
label	String	The human-readable name of the blockchain (e.g., "Polygon zkEVM").
features	Array[String]	List of features supported by Blocknative on this chain (e.g., ["blockprices"]).
icon	String	URL to the blockchain's icon.
system	String	The human-readable name of the ecosystem, (e.g. "ethereum" or "bitcoin")
network	String	Internal name of the blockchain (e.g. "mainnet" or "sepolia"). See chain table.

Notes

• The list of supported blockchains and available features may change as new networks are integrated.

• This endpoint does not include gas price data—use the /blockprices endpoint for real-time gas estimations.