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

# EVM integration

> Autheo Chain's Ethermint EVM runtime, JSON-RPC endpoints, address formats, ERC-721 license hooks, and Ethereum tool compatibility.

Autheo Chain runs a full Ethermint EVM derived from the Cronos codebase. A single `eth_secp256k1` keypair controls both Cosmos and EVM transactions, and all standard Ethereum development tools work without modification.

## JSON-RPC endpoints

| Port | Protocol  | Default binding |
| ---- | --------- | --------------- |
| 8545 | HTTP      | `127.0.0.1`     |
| 8546 | WebSocket | `127.0.0.1`     |

Available namespaces:

| Namespace  | Exposed publicly      | Notes                     |
| ---------- | --------------------- | ------------------------- |
| `eth`      | Yes                   | Full Ethereum JSON-RPC    |
| `net`      | Yes                   | Network info              |
| `web3`     | Yes                   | Client version            |
| `autheo`   | Public RPC nodes only | Chain-specific extensions |
| `debug`    | No                    | Internal only             |
| `personal` | No                    | Internal only             |

<Warning>
  Never expose the `debug` or `personal` namespaces on public-facing nodes. Use a reverse proxy with TLS on ports 8545 and 8546 for any public RPC endpoint.
</Warning>

## Address interoperability

Each account has three equivalent representations:

| Format                | Example                | Use                          |
| --------------------- | ---------------------- | ---------------------------- |
| Cosmos Bech32         | `autheo1abc...`        | Cosmos transactions, queries |
| Validator Bech32      | `autheovaloper1abc...` | Validator operations         |
| Ethereum hex (EIP-55) | `0xAbCd...`            | EVM transactions, MetaMask   |

```bash theme={null}
autheod keys show <key-name> --keyring-backend file           # Cosmos
autheod keys show <key-name> --bech val --keyring-backend file # Validator
autheod keys show <key-name> --bech eth --keyring-backend file # Ethereum hex
```

## ERC-721 license minting hook

When Ethermint processes an ERC-721 `Transfer` event from a recognized contract, the `x/license` EVM hook fires synchronously:

1. Identifies the contract category (Sovereign, Prime, or Core) from module parameters
2. Maps the EVM recipient address to its Cosmos Bech32 equivalent
3. Creates a `LicenseRecord` with `ISSUED` status
4. Deduplicates using `(originChain, originContract, tokenId)` — returns `ErrLicenseAlreadyMinted` for duplicates

```bash theme={null}
autheod query license params   # View current contract addresses
```

## Ethereum tool compatibility

When connecting tools to a **local node** (e.g., during development), use port `8545` and the chain ID matching your node's network. When connecting to public endpoints, use the values below.

| Tool      | Local node                                            | Mainnet (public)                                        | Testnet (public)                                                |
| --------- | ----------------------------------------------------- | ------------------------------------------------------- | --------------------------------------------------------------- |
| MetaMask  | `http://localhost:8545`, Chain ID: `2127`             | `https://rpc1.autheo.com`, Chain ID: `2127`             | `https://testnet-rpc1.autheo.com`, Chain ID: `785`              |
| ethers.js | `new ethers.JsonRpcProvider("http://localhost:8545")` | `new ethers.JsonRpcProvider("https://rpc1.autheo.com")` | `new ethers.JsonRpcProvider("https://testnet-rpc1.autheo.com")` |
| Hardhat   | `chainId: 2127`                                       | `chainId: 2127`                                         | `chainId: 785`                                                  |
| Foundry   | `--rpc-url http://localhost:8545`                     | `--rpc-url https://rpc1.autheo.com`                     | `--rpc-url https://testnet-rpc1.autheo.com`                     |

## Deploying contracts

<Tabs>
  <Tab title="ethers.js">
    ```javascript theme={null}
    const provider = new ethers.JsonRpcProvider("http://localhost:8545");
    const wallet = new ethers.Wallet(privateKey, provider);
    const factory = new ethers.ContractFactory(abi, bytecode, wallet);
    const contract = await factory.deploy();
    ```
  </Tab>

  <Tab title="Hardhat">
    ```javascript theme={null}
    // hardhat.config.js
    networks: {
      autheoMainnet: {
        url: "https://rpc1.autheo.com",
        chainId: 2127,
        accounts: [privateKey]
      },
      autheoTestnet: {
        url: "https://testnet-rpc1.autheo.com",
        chainId: 785,
        accounts: [privateKey]
      }
    }
    ```
  </Tab>

  <Tab title="Foundry">
    ```bash theme={null}
    forge create --rpc-url http://localhost:8545 \
      --private-key <private-key> \
      src/MyContract.sol:MyContract
    ```
  </Tab>
</Tabs>