Supported Chains

Overview

Returns information about supported EVM blockchain networks. This endpoint provides the canonical list of chain identifiers and names that can be used across other EVM endpoints in the Cambrian API.

Business Value

• Network Discovery: Easily identify which EVM networks are available for data queries
• Integration Planning: Plan multi-chain applications by understanding supported networks
• Chain Validation: Verify chain compatibility before making network-specific API calls
• Development Support: Simplify blockchain application development with network enumeration
• Network Monitoring: Track the expansion of supported blockchain networks over time

Endpoint Details

URL:

https://api.cambrian.org/evm/chains

Method: GET
Authentication: Required via X-API-Key header

Query Parameters

Response Field Descriptions

Examples

1. List Supported EVM Chains

Retrieve the full list of EVM chains currently supported by the API.

curl -X GET "https://api.cambrian.org/evm/chains" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json"

Response:

[
  {
    "columns": [
      {
        "name": "id",
        "type": "UInt32"
      },
      {
        "name": "name",
        "type": "String"
      }
    ],
    "data": [
      [
        1,
        "ethereum"
      ],
      [
        8453,
        "base"
      ]
    ],
    "rows": 2
  }
]

Note: result collections are limited to 10 items.

The response returns 2 supported chains: Ethereum (chain ID 1) and Base (chain ID 8453).

x402 Payment Option

This endpoint supports pay-per-use access via the x402 payment protocol (v2): pay $0.05 USDC per request using blockchain micropayments. No API key required.

Quick Start (TypeScript)

npm install @x402/fetch @x402/evm viem

import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const signer = privateKeyToAccount(process.env.EVM_PRIVATE_KEY as `0x${string}`);
const client = new x402Client();
client.register("eip155:*", new ExactEvmScheme(signer));

const fetchWithPayment = wrapFetchWithPayment(fetch, client);
const response = await fetchWithPayment(
  "https://x402.cambrian.org/evm/chains"
);
const data = await response.json();

Quick Start (Python)

pip install "x402[httpx]"

import asyncio, os
from eth_account import Account
from x402 import x402Client
from x402.http.clients import x402HttpxClient
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

async def main():
    client = x402Client()
    account = Account.from_key(os.getenv("EVM_PRIVATE_KEY"))
    register_exact_evm_client(client, EthAccountSigner(account))

    async with x402HttpxClient(client) as http:
        response = await http.get("https://x402.cambrian.org/evm/chains")
        print(response.json())

asyncio.run(main())

Payment Flow

1. Send a normal request to the endpoint (no API key needed)
2. Server returns 402 Payment Required with payment details
3. The x402 SDK automatically signs a payment authorization with your wallet
4. The SDK resubmits the request with the signed payment
5. Server verifies payment and returns the API response

The x402 SDK handles steps 2 through 5 automatically.

Network: Base (chain ID 8453) | Currency: USDC | Price: $0.05 per request