Chain ID API

The EIP-155 chain ID for any supported network via eth_chainId — the read multi-chain agents make to confirm which chain an RPC is on before signing.

Overview

The EIP-155 chain ID for any supported network via eth_chainId — the read multi-chain agents make to confirm which chain an RPC is on before signing. Across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. Free public RPC; 6 chains vs onesource's Ethereum-only coverage. List your own x402 service on bazaar.upstream/listings: 1 USD, 30 days, live at once, no account.

Endpoint

Method	Endpoint	Price	Description
GET	/v1/marketplace/api/chain-id-2597	$0.0115	Invoke Chain Id (Social) and return the upstream response.

How to call it

Requests are paid per call over the x402 protocol. Call the endpoint, receive a 402 Payment Required quote, then repeat the request with the signed payment header. The SDKs do both steps for you.

# 1. Ask for a quote
curl -i https://jarvisclaw.ai/v1/marketplace/api/chain-id-2597

# 2. Pay it (the SDK signs and retries for you)
curl -H "X-PAYMENT: <signed-payload>" https://jarvisclaw.ai/v1/marketplace/api/chain-id-2597

Open in the marketplace