API Reference: Basics

JSON-RPC basics

Every EVM chain on Instanodes speaks standard JSON-RPC 2.0 over HTTPS. Send a POST request with a method, a params array, and an id. Instanodes answers with a result field or an error field. Non-EVM chains follow their own native RPC conventions, covered per chain in Chains & Networks. The transport pattern stays consistent across chains: post a JSON body, get a JSON response. Most HTTP client code stays reusable across chains as a result.

WebSocket subscriptions

New blocks, pending transactions, and log events should not get polled. Instanodes exposes WebSocket endpoints alongside the HTTPS ones for exactly this. Subscribe once and receive push notifications as events happen, instead of repeatedly asking whether anything changed.

const WebSocket = require("ws");
const ws = new WebSocket("wss://eth.instanodes.io/v1/{api-key}");

ws.on("open", () => {
  ws.send(JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "eth_subscribe",
    params: ["newHeads"],
  }));
});

ws.on("message", (data) => console.log(JSON.parse(data)));

Authentication

Your API key sits embedded directly in the endpoint URL (https://{chain}.instanodes.io/v1/{api-key}), instead of a separate header. Most providers in this category use the same pattern. Treat the URL as a secret. Anyone holding the URL makes requests against your quota. Rotate keys from the dashboard the moment one leaks, instead of trying to selectively block traffic after the fact.

See Rate Limits by Tier for how quota is enforced, and Common Methods & Error Handling for request examples and what happens when something goes wrong.

Docs

API Reference: Basics

JSON-RPC basics

WebSocket subscriptions

const WebSocket = require("ws");
const ws = new WebSocket("wss://eth.instanodes.io/v1/{api-key}");

ws.on("open", () => {
  ws.send(JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "eth_subscribe",
    params: ["newHeads"],
  }));
});

ws.on("message", (data) => console.log(JSON.parse(data)));

Authentication

See Rate Limits by Tier for how quota is enforced, and Common Methods & Error Handling for request examples and what happens when something goes wrong.