Networks, Public RPC Endpoints, & APIs
Developer Tip
We recommend using Alchemy (opens new window) for its scalablity, reliability, and data accuracy.
Note
Some API calls, such as the those in the personal namespace (opens new window) make no sense in a shared environment. Such RPCs are either totally unsupported, or will return nonsensical values.
# Optimism (mainnet)
| Parameter | Value |
|---|---|
| Network Name | Optimism |
| Description | Mainnet |
| Chain ID | 10 |
| Explorer | https://optimistic.etherscan.io (opens new window) |
| HTTP Endpoint1 | We recommend Alchemy (opens new window). Optimism also provides this endpoint: https://mainnet.optimism.io. But it is not for production systems and is rate limited. |
| WebSocket Endpoint2 | wss://ws-mainnet.optimism.io |
| L1 Contract Addresses | link (opens new window) |
| L2 Contract Addresses | link (opens new window) |
| chainid.link | https://chainid.link/?network=optimism (opens new window) |
(1) Some API calls, such as those in the personal namespace (opens new window) make no sense in a shared environment. Such RPCs are either not supported, or will return nonsensical values.
(2) The WebSocket endpoint is only supported for the two operations that cannot be provided on an HTTP endpoint: eth_subscribe and eth_unsubscribe.
If you need a general purpose WebSocket endpoint, get one from a service provider._
# API Options:
Get free access to Optimism through Alchemy (opens new window)
For small scale tests, you can use our public API:
- HTTP endpoint: https://mainnet.optimism.io (opens new window) (note, this is for testing. For production, use Alchemy)
- WebSocket endpoint (limited usage, see footnote below the table): wss://ws-mainnet.optimism.io
You can run a large application for free using Alchemy (opens new window). We’ve done extensive diligence and Alchemy is our recommendation due to reliability, scalability, and data correctness. They're the default API provider and developer platform for top projects like OpenSea and Facebook.
# Optimism Goerli
Purpose
This is our new test network.
| Parameter | Value |
|---|---|
| Network Name | Optimism Goerli |
| Description | Testnet (public) |
| Chain ID | 420 |
| Explorer | https://goerli-optimism.etherscan.io/ (opens new window) |
| HTTP Endpoint | https://goerli.optimism.io |
| WebSocket Endpoint | wss://ws-goerli.optimism.io |
| L1 Contract Addresses | link (opens new window) |
| L2 Contract Addresses | link (opens new window) |
| chainid.link | https://chainid.link/?network=optimism-goerli (opens new window) |
# API Options
Get free access to Optimism through Alchemy (opens new window)
For small scale tests, you can use our public API:
- HTTP endpoint: https://goerli.optimism.io (opens new window) (note, this is for testing. For production, use Alchemy)
- WebSocket endpoint (limited usage, see footnote below the table): wss://ws-goerli.optimism.io
You can run a large application for free using Alchemy (opens new window). We’ve done extensive diligence and Alchemy is our recommendation due to reliability, scalability, and data correctness. They're the default API provider and developer platform for top projects like OpenSea and Facebook.
# Test ETH
The Optimism Faucet (opens new window) now provides Optimism Goerli ETH. Alternatively, if you already have Goerli ETH, you can bridge it (opens new window).
# Optimism Kovan (old testnet)
Deprecation notice
We are transitioning our test network to Goerli. Optimism Kovan end of life is October 5th, 2022. Be sure to migrate from Kovan to Goerli (opens new window) well before then.
| Parameter | Value |
|---|---|
| Network Name | Optimism Kovan |
| Description | Testnet (public) |
| Chain ID | 69 |
| Explorer | https://kovan-optimistic.etherscan.io (opens new window) |
| HTTP Endpoint | https://kovan.optimism.io If you are going to be sending a lot of requests, please set up a free account with Alchemy |
| WebSocket Endpoint1 | wss://ws-kovan.optimism.io If you are going to be sending a lot of requests, please set up a free account with Alchemy |
| L1 Contract Addresses | link (opens new window) |
| L2 Contract Addresses | link (opens new window) |
| chainid.link | https://chainid.link/?network=optimism-kovan (opens new window) |
(1) The WebSocket endpoint is only supported for the two operations that cannot be provided on an HTTP endpoint: eth_subscribe and eth_unsubscribe.
If you need a general purpose WebSocket endpoint, get one from a service provider.