> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uniblock.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Optimism (ETH) Overview

Optimism (ETH) RPC

Use Uniblock's JSON-RPC endpoint to access Optimism (ETH) with low-latency routing and a single API surface across providers.

## What is Optimism?

Optimism is an EVM-compatible mainnet. Its ticker symbol is `ETH`.

## What is the Optimism (ETH) JSON-RPC API?

The JSON-RPC API is the standard interface for reading chain state, sending transactions, and interacting with smart contracts where supported.

## Making API requests

Send a POST request to `https://api.uniblock.dev/uni/v1/json-rpc?chainId=10`. Include the JSON-RPC method and params in the request body.

## Supported networks

| Network          | Symbol | Type    | Chain ID   |
| ---------------- | ------ | ------- | ---------- |
| Optimism         | `ETH`  | Mainnet | `10`       |
| Optimism Sepolia | `ETH`  | Testnet | `11155420` |

## API reference

Browse the available method groups for this chain:

* [Debug](/reference/jsonrpc-docs/10/debug/debug-account-range)
* [Erigon](/reference/jsonrpc-docs/10/erigon/erigon-block-number)
* [EVM](/reference/jsonrpc-docs/10/evm/eth-accounts)
* [Otterscan](/reference/jsonrpc-docs/10/otterscan/ots-get-api-level)
* [Trace](/reference/jsonrpc-docs/10/trace/trace-block)