🔎 OP Scan

OP Scan is a transaction explorer tailored specifically for the OP Stack (opens in a new tab) and the Superchain vision (opens in a new tab). It's focused on being lightweight so that anyone can run it locally next to an OP Stack devnet or any other compatible OP Stack based rollup.

⚙️ Installation

Getting Started Video

Here's a video walkthrough (opens in a new tab) on how to launch the explorer locally configured for OP Sepolia testnet.

Required Dependencies

The app requires the following dependencies:

Node.js >= 20
pnpm >= 9

Explorer Configuration

Clone this repository:

git clone https://github.com/walnuthq/op-scan.git

Install the dependencies:

pnpm install

Copy .env.local.example into .env.local at the root of your repository and populate it with your own values. In particular, configure both L1 and L2 chains:

NEXT_PUBLIC_L1_CHAIN_ID="11155111"
NEXT_PUBLIC_L1_NAME="Sepolia"
NEXT_PUBLIC_L1_RPC_URL="https://ethereum-sepolia-rpc.publicnode.com"
NEXT_PUBLIC_L2_CHAIN_ID="11155420"
NEXT_PUBLIC_L2_NAME="OP Sepolia"
NEXT_PUBLIC_L2_RPC_URL="https://optimism-sepolia-rpc.publicnode.com"

You can get free node rpcs url by signing up to services such as Alchemy (opens in a new tab), Infura (opens in a new tab) or QuickNode (opens in a new tab).

For devnet usage, specify the L1 contract addresses:

NEXT_PUBLIC_OPTIMISM_PORTAL_ADDRESS="..."
NEXT_PUBLIC_L1_CROSS_DOMAIN_MESSENGER_ADDRESS="..."

You will find theses addresses in your rollup deployment artifacts in contracts-bedrock/deployments/your-deployment/L1Contract.json. Note that you always need to provide the proxy address, not the underlying contract.

If you don't want to run the explorer with your local chain setup, you will find all the necessary environment variables in .env.local.example to configure the explorer with OP Sepolia or OP Mainnet.

If you want to be able to use the Write Contract feature on verified contracts, you will also need to provide a Reown (opens in a new tab) project ID.

NEXT_PUBLIC_REOWN_PROJECT_ID="REOWN_PROJECT_ID"

Indexer Configuration

To run the indexer, first set up your DATABASE_URL in .env.local (we use SQLite by default, but you can switch to PostgreSQL by changing the Prisma provider in prisma/schema.prisma) and configure websocket connections to your L1/L2 chains:

DATABASE_URL="file:dev.db"
L1_RPC_WS="wss://ethereum-sepolia-rpc.publicnode.com"
L2_RPC_WS="wss://optimism-sepolia-rpc.publicnode.com"

Then you can sync your local database with the Prisma schema:

pnpm prisma:db:push

Now you will be able to start indexing the blockchain by running the op-indexer command:

pnpm op-indexer

You should start seeing blocks getting indexed in your terminal, and you can explore the state of your local database using Prisma studio:

pnpm prisma:studio

If you need to change the Prisma schema at some point, make sure to regenerate the Prisma client and push to your local database:

pnpm prisma:generate
pnpm prisma:db:push

Indexing a blockchain puts a heavy load on the RPC endpoint, as you need to perform many JSON-RPC requests to fully index a block (along with transactions and logs). When indexing non-local chains you will probably encounter 429 errors related to rate-limiting, you may provide up to 5 fallback RPC URLs in case this happens:

NEXT_PUBLIC_L1_FALLBACK1_RPC_URL="https://rpc.ankr.com/eth_sepolia"
NEXT_PUBLIC_L2_FALLBACK1_RPC_URL="https://rpc.ankr.com/optimism_sepolia"
NEXT_PUBLIC_L1_FALLBACK2_RPC_URL="https://endpoints.omniatech.io/v1/eth/sepolia/public"
NEXT_PUBLIC_L2_FALLBACK2_RPC_URL="https://endpoints.omniatech.io/v1/op/sepolia/public"
NEXT_PUBLIC_L1_FALLBACK3_RPC_URL="https://sepolia.drpc.org"
NEXT_PUBLIC_L2_FALLBACK3_RPC_URL="https://optimism-sepolia.drpc.org"
NEXT_PUBLIC_L1_FALLBACK4_RPC_URL="https://eth-sepolia.g.alchemy.com/v2/FALLBACK4_API_KEY"
NEXT_PUBLIC_L2_FALLBACK4_RPC_URL="https://opt-sepolia.g.alchemy.com/v2/FALLBACK4_API_KEY"
NEXT_PUBLIC_L1_FALLBACK5_RPC_URL="https://sepolia.infura.io/v3/FALLBACK5_API_KEY"
NEXT_PUBLIC_L2_FALLBACK5_RPC_URL="https://optimism-sepolia.infura.io/v3/FALLBACK5_API_KEY"

You can pass several parameters to the indexer to control the indexing range and execution:

• --l2-from-block (short -f, defaults to latest block) start indexing from this L2 block.
• --l2-index-block (short -b) index this particular L2 block number.
• --l1-from-block (defaults to latest block) start indexing from this L1 block.
• --l1-index-block index this particular L1 block number.
• --index-delay (short -d, defaults to 1000) delay in ms between indexing 2 blocks to avoid overloading the RPC.

Example of running the indexer:

pnpm op-indexer -f 123416717 --l1-index-block 20426733 --l1-index-block 20426726 -d 500

Running the Explorer

When you're done configuring your environment variables, you can build the app:

pnpm build

Make sure the indexer is running, then launch the explorer to see it live at http://localhost:3000

pnpm start

Alternatively, you can launch the explorer in dev mode if you want to customize it:

pnpm dev