Chains API

Access supported blockchain networks and contract information.

List Chains

GET /api/chains

Returns all supported blockchain networks. The catalog is public, so this endpoint answers with or without a credential. To confirm an API key is valid, call GET /api/keys instead. See Checking a key works.

Query Parameters

Response

Returns a bare JSON array of chain objects. The response is not wrapped in a data envelope.

[
  {
    "id": "chain_1",
    "chainId": 1,
    "name": "Ethereum Mainnet",
    "symbol": "ETH",
    "chainType": "evm",
    "explorerUrl": "https://etherscan.io",
    "explorerAddressPath": "/address/",
    "explorerApiUrl": "https://api.etherscan.io",
    "explorerApiType": "etherscan",
    "isTestnet": false,
    "isEnabled": true,
    "usePrivateMempoolRpc": false
  },
  {
    "id": "chain_2",
    "chainId": 11155111,
    "name": "Sepolia",
    "symbol": "ETH",
    "chainType": "evm",
    "explorerUrl": "https://sepolia.etherscan.io",
    "explorerAddressPath": "/address/",
    "explorerApiUrl": "https://api-sepolia.etherscan.io",
    "explorerApiType": "etherscan",
    "isTestnet": true,
    "isEnabled": true,
    "usePrivateMempoolRpc": false
  }
]

Response Fields

RPC endpoint URLs (defaultPrimaryRpc, defaultFallbackRpc) are not returned by this endpoint. They may embed provider API keys and are read server-side only; client code should use the user-configurable RPC preferences API instead.

Private Mempool Capability

usePrivateMempoolRpc describes a chain capability, not the route used by a specific transaction. A true value makes the chain’s (Flashbots) variant available on supported workflow write actions. Selecting that variant stores usePrivateMempool: true in the action configuration. Programmatic workflow definitions can set the same field directly.

Private routing is strict by default: when the private RPC is available, its public fallback is removed. Set strict: false only when falling back to the public mempool is acceptable. If a stored action requests private routing after the chain capability is removed, execution proceeds through the public RPC and logs a warning.

Private-mempool writes are not gas sponsored because Turnkey sponsorship uses its own broadcast path. The direct-execution API and MCP execute tools do not currently expose the workflow action’s usePrivateMempool or strict fields.

Neither this chain capability nor a saved workflow setting confirms that a specific transaction used a private route. Current execution outputs do not include a public/private route field, so describe the route as requested unless you have separate relay evidence.

Chain Types

Chain Identifiers

KeeperHub action and execute endpoints accept either of two equivalent fields for selecting the target chain:

• chainId (canonical): the numeric chain ID. Send a number or a stringified number. Examples: 1, 8453, 11155111.
• network (deprecated alias): same field, retained for backward compatibility. In addition to numeric chain IDs, it resolves the common chain names below.

Prefer chainId in new clients. Both fields produce identical behavior; passing both is treated as chainId winning.

Accepted Chain Names

These string aliases are normalized to the numeric chain ID before routing. Names are case-insensitive.

Numeric chain IDs (as number or string) are accepted on every chain, including any chain present in GET /api/chains that does not appear in the alias table above.

Fetch Contract ABI

GET /api/chains/{chainId}/abi?address={contractAddress}

Fetches the ABI for a verified contract from the block explorer. The {chainId} path parameter is the numeric chain ID (e.g., 1, 8453, 11155111), not a chain name and not the internal id field from GET /api/chains.

Query Parameters

Response

{
  "success": true,
  "abi": [
    {
      "type": "function",
      "name": "balanceOf",
      "inputs": [{"name": "account", "type": "address"}],
      "outputs": [{"name": "", "type": "uint256"}]
    }
  ],
  "explorerUrl": "https://etherscan.io"
}