When building applications for use with your OP Stack, you can continue to use [the Optimism JavaScript SDK](https://sdk.optimism.io/).
The main difference is you need to provide some contract addresses to the `CrossDomainMessenger` because they aren't preconfigured.
## Natively supported chains
## Contract addresses
[The OP Stack Client SDK](https://sdk.optimism.io/) natively supports multiple OP Chains: OP, Base, etc.
To see whether a specific OP Chain is supported directly, [see the documentation](https://sdk.optimism.io/enums/l2chainid).
### L1 contract addresses
## Not natively supported chains
The contract addresses are in `.../optimism/packages/contracts-bedrock/deployments/getting-started`, which you created when you deployed the L1 contracts.
If you are using a chain that is *not* natively supported, for example an OP Stack chain [you just created](./getting-started.md), you can continue to use [the OP Stack Client SDK](https://sdk.optimism.io/).
You just need to provide some contract addresses to the `CrossDomainMessenger` because they aren't preconfigured.
### Getting contract addresses
#### L1 contract addresses
If you followed the directions in [Getting Started](./getting-started.md), the contract addresses are in `.../optimism/packages/contracts-bedrock/deployments/getting-started`, which you created when you deployed the L1 contracts.
| Contract name when creating `CrossDomainMessenger` | File with address |
| - | - |
...
...
@@ -22,9 +29,9 @@ The contract addresses are in `.../optimism/packages/contracts-bedrock/deploymen
| `L2OutputOracle` | `L2OutputOracleProxy.json`
### Unneeded contract addresses
#### Unneeded contract addresses
Some contracts are required by the SDK, but not actually used.
Some contracts are required by the SDK as a sanity check, but are not actually used.
For these contracts you can just specify the zero address:
-`StateCommitmentChain`
...
...
@@ -33,7 +40,7 @@ For these contracts you can just specify the zero address:
In JavaScript you can create the zero address using the expression `"0x".padEnd(42, "0")`.
## The CrossChainMessenger object
### The CrossChainMessenger object
These directions assume you are inside the [Hardhat console](https://hardhat.org/hardhat-runner/docs/guides/hardhat-console).
They further assume that your project already includes the Optimism SDK [`@eth-optimism/sdk`](https://www.npmjs.com/package/@eth-optimism/sdk).
...
...
@@ -113,7 +120,7 @@ They further assume that your project already includes the Optimism SDK [`@eth-o
})
```
## Verify SDK functionality
### Verify SDK functionality
To verify the SDK's functionality, transfer some ETH from L1 to L2.