address PR review comments for self-anchoring docs

- Add anchor contract section with pre-deployed addresses (Ethereum, Gnosis)
- Add deployment instructions linking to ceramic-anchor-service repo
- Replace --ethereum-rpc-urls with --evm-rpc-url (used for both submit and verify)
- Add --additional-chain-rpc-urls for validating anchors from other chains
- Update all examples to use simplified configuration

Author: Mohsin Zaidi

docs/protocol/ceramic-one/anchoring/evm-configuration.mdx

@@ -7,43 +7,94 @@ description: Configure self-anchoring for any EVM-compatible blockchain
 
 This guide covers the configuration options for running self-anchoring on EVM-compatible blockchains.
 
-## Required Options
+## Anchor Contract
 
-Self-anchoring requires both anchor verification RPC endpoints and transaction submission configuration:
+Self-anchoring requires an anchor contract deployed on your chosen EVM blockchain.
 
-### Anchor Proof Verification
+### Pre-deployed Contracts
 
-| Option | Environment Variable | Description |
-|--------|---------------------|-------------|
-| `--ethereum-rpc-urls` | `CERAMIC_ONE_ETHEREUM_RPC_URLS` | Comma-separated list of RPC URLs for verifying anchor proofs |
+The anchor contract is already deployed on the following networks:
+
+| Network | Chain ID | Contract Address |
+|---------|----------|------------------|
+| Ethereum Mainnet | 1 | `0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC` |
+| Gnosis Chain | 100 | `0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC` |
+
+You can use these addresses directly with `--evm-contract-address` without deploying your own contract.
+
+### Deploying to Other Networks
+
+To deploy the anchor contract on a different EVM chain:
+
+The contract source code is available at:
+[ceramicnetwork/ceramic-anchor-service/contracts](https://github.com/ceramicnetwork/ceramic-anchor-service/tree/develop/contracts)
+
+The contract (`CeramicAnchorServiceV2.sol`) implements [CIP-110](https://github.com/ceramicnetwork/CIPs/blob/main/CIPs/cip-110.md) for indexable anchors.
+
+**Deployment steps:**
+
+1. Clone the repository:
+   ```bash
+   git clone https://github.com/ceramicnetwork/ceramic-anchor-service.git
+   cd ceramic-anchor-service/contracts
+   ```
 
-This is required for validating anchor proofs, including the proofs created by your own self-anchoring. The node uses these endpoints to verify that anchors exist on-chain.
+2. Install dependencies (requires [Foundry](https://book.getfoundry.sh/getting-started/installation)):
+   ```bash
+   make installDeps
+   make build
+   ```
 
-### Transaction Submission
+3. Deploy to your network:
+   ```bash
+   export ETH_WALLET_PK=your-private-key
+   export ETH_RPC_HOST=https://rpc.yournetwork.com
+   export ETH_RPC_PORT=443
+   make create
+   ```
+
+4. Note the deployed contract address from the output for use with `--evm-contract-address`.
+
+## Required Options
 
 All of these options must be provided together to enable self-anchoring:
 
 | Option | Environment Variable | Description |
 |--------|---------------------|-------------|
-| `--evm-rpc-url` | `CERAMIC_ONE_EVM_RPC_URL` | RPC endpoint URL for submitting anchor transactions |
+| `--evm-rpc-url` | `CERAMIC_ONE_EVM_RPC_URL` | RPC endpoint URL for submitting anchor transactions and verifying anchor proofs |
 | `--evm-private-key` | `CERAMIC_ONE_EVM_PRIVATE_KEY` | Private key in hex format (without 0x prefix) |
 | `--evm-chain-id` | `CERAMIC_ONE_EVM_CHAIN_ID` | Network/chain ID (e.g., 1 for Ethereum mainnet) |
-| `--evm-contract-address` | `CERAMIC_ONE_EVM_CONTRACT_ADDRESS` | Deployed anchor contract address |
+| `--evm-contract-address` | `CERAMIC_ONE_EVM_CONTRACT_ADDRESS` | Deployed anchor contract address (see [Deploying the Anchor Contract](#deploying-the-anchor-contract)) |
+
+The `--evm-rpc-url` is used both for submitting anchor transactions and for verifying anchor proofs on that chain.
 
 ## Optional Settings
 
 | Option | Environment Variable | Default | Description |
 |--------|---------------------|---------|-------------|
 | `--evm-confirmations` | `CERAMIC_ONE_EVM_CONFIRMATIONS` | 4 | Number of block confirmations before anchor is final |
 | `--anchor-interval` | `CERAMIC_ONE_ANCHOR_INTERVAL` | 3600 | Anchoring frequency in seconds |
+| `--additional-chain-rpc-urls` | `CERAMIC_ONE_ADDITIONAL_CHAIN_RPC_URLS` | - | Comma-separated list of RPC URLs for validating anchors from other chains |
+
+### Validating Anchors from Other Chains
+
+If your node syncs events from the network that were anchored on different chains (e.g., historical anchors or events from other nodes), you can provide additional RPC endpoints to validate those proofs:
+
+```bash
+ceramic-one daemon \
+  --evm-rpc-url https://rpc.gnosis.io \
+  --additional-chain-rpc-urls https://eth-mainnet.g.alchemy.com/v2/YOUR_KEY,https://polygon-rpc.com \
+  ...
+```
+
+The node uses the first valid RPC for each chain ID.
 
 ## Configuration Methods
 
 ### CLI Flags
 
 ```bash
 ceramic-one daemon \
-  --ethereum-rpc-urls https://rpc.yournetwork.com \
   --evm-rpc-url https://rpc.yournetwork.com \
   --evm-private-key abcd1234... \
   --evm-chain-id 12345 \
@@ -55,7 +106,6 @@ ceramic-one daemon \
 ### Environment Variables
 
 ```bash
-export CERAMIC_ONE_ETHEREUM_RPC_URLS=https://rpc.yournetwork.com
 export CERAMIC_ONE_EVM_RPC_URL=https://rpc.yournetwork.com
 export CERAMIC_ONE_EVM_PRIVATE_KEY=abcd1234...
 export CERAMIC_ONE_EVM_CHAIN_ID=12345
@@ -76,7 +126,6 @@ services:
     image: public.ecr.aws/r5b3e0r5/3box/ceramic-one:latest
     network_mode: "host"
     environment:
-      - CERAMIC_ONE_ETHEREUM_RPC_URLS=https://rpc.yournetwork.com
       - CERAMIC_ONE_EVM_RPC_URL=https://rpc.yournetwork.com
       - CERAMIC_ONE_EVM_PRIVATE_KEY=${EVM_PRIVATE_KEY}
       - CERAMIC_ONE_EVM_CHAIN_ID=12345

docs/protocol/ceramic-one/anchoring/overview.mdx

@@ -28,20 +28,14 @@ When events are anchored:
 Before configuring self-anchoring, ensure you have:
 
 1. **A running Ceramic One node** - See [Installation](../usage/installation)
-2. **Access to EVM RPC endpoints** - For both submitting transactions and verifying anchor proofs
+2. **Access to an EVM RPC endpoint** - For submitting transactions and verifying anchor proofs
 3. **A funded wallet** - The wallet must have sufficient funds for transaction fees on your chosen network
-4. **The anchor contract address** - The deployed Ceramic anchor contract on your target network
+4. **A deployed anchor contract** - See [Deploying the Anchor Contract](./evm-configuration#deploying-the-anchor-contract)
 
 ## Quick Start
 
-Self-anchoring requires two types of RPC configuration:
-
-1. **`--ethereum-rpc-urls`** - For verifying anchor proofs (required)
-2. **`--evm-rpc-url`** - For submitting anchor transactions (required for self-anchoring)
-
 ```bash
 ceramic-one daemon \
-  --ethereum-rpc-urls https://rpc.yournetwork.com \
   --evm-rpc-url https://rpc.yournetwork.com \
   --evm-private-key your-private-key-hex \
   --evm-chain-id 1 \
@@ -52,7 +46,6 @@ ceramic-one daemon \
 Or use environment variables:
 
 ```bash
-export CERAMIC_ONE_ETHEREUM_RPC_URLS=https://rpc.yournetwork.com
 export CERAMIC_ONE_EVM_RPC_URL=https://rpc.yournetwork.com
 export CERAMIC_ONE_EVM_PRIVATE_KEY=your-private-key-hex
 export CERAMIC_ONE_EVM_CHAIN_ID=1
@@ -68,19 +61,19 @@ See [EVM Configuration](./evm-configuration) for detailed setup instructions and
 
 | Option | Environment Variable | Purpose |
 |--------|---------------------|---------|
-| `--ethereum-rpc-urls` | `CERAMIC_ONE_ETHEREUM_RPC_URLS` | Verify anchor proofs from the network |
-| `--evm-rpc-url` | `CERAMIC_ONE_EVM_RPC_URL` | Submit anchor transactions |
+| `--evm-rpc-url` | `CERAMIC_ONE_EVM_RPC_URL` | Submit anchor transactions and verify proofs |
 | `--evm-private-key` | `CERAMIC_ONE_EVM_PRIVATE_KEY` | Sign anchor transactions |
 | `--evm-chain-id` | `CERAMIC_ONE_EVM_CHAIN_ID` | Target blockchain network |
 | `--evm-contract-address` | `CERAMIC_ONE_EVM_CONTRACT_ADDRESS` | Anchor contract address |
+| `--additional-chain-rpc-urls` | `CERAMIC_ONE_ADDITIONAL_CHAIN_RPC_URLS` | Validate anchors from other chains (optional) |
 
 ## How It Works
 
 1. **Event Collection**: Ceramic One collects pending events that need anchoring
 2. **Merkle Tree Construction**: Events are batched and organized into a Merkle tree
 3. **Blockchain Transaction**: The Merkle root is written to the anchor contract on your chosen EVM chain
 4. **Confirmation**: After the configured number of block confirmations, anchors are considered final
-5. **Proof Verification**: The node verifies anchor proofs using `--ethereum-rpc-urls`
+5. **Proof Verification**: The node verifies anchor proofs using the configured RPC endpoints
 6. **Proof Distribution**: Anchor proofs are distributed to relevant streams
 
 ## Next Steps