# Chain ID and Address Format

## Chain ID

Cronos has different Chain IDs to distinguish between the *devnet*, *testnet* and *mainnet*. When running Cronos in your local environment, you will need to decide your own Chain ID.

For example, our testnet Chain ID is `cronostestnet_338-3`.

## Address prefix

[BIP-0173](https://github.com/satoshilabs/slips/blob/master/slip-0173.md) defines a new format for segregated witness output addresses that contains a human-readable part which identifies the coin type. Cronos has different address prefixes for its corresponding network types, these prefixes are:

| Testnet |
| ------- |
| `tcrc`  |

Cronos uses the Bech32 address format wherever users must handle binary data. Bech32 encoding provides robust integrity checks on data and the human readable part (HRP) that provides contextual hints that can assist UI developers with providing informative error messages. Specifically, we have the following HRP prefixes for different address types in the mainnet:

|                    | Address bech32 Prefix |
| ------------------ | --------------------- |
| Account            | `tcrc`                |
| Validator Operator | `tcrcvaloper`         |
| Consensus Nodes    | `tcrcvalcons`         |

We can use the `keys show` command of `cronosd` with the flag `--bech <type> (acc|val|cons)` to obtain the addresses and keys as mentioned above.\
For example:

```bash
$ cronosd keys show mykey --bech acc
- name: mykey
  type: local
  address: tcrc1qsklxwt77qrxur494uvw07zjynu03dq9alwh37
  pubkey: '{"@type":"/ethermint.crypto.v1alpha1.ethsecp256k1.PubKey","key":"A8nbJ3eW9oAb2RNZoS8L71jFMfjk6zVa1UISYgKK9HPm"}'
  mnemonic: ""

$ cronosd keys show test --bech val
- name: mykey
  type: local
  address: tcrcvaloper1qsklxwt77qrxur494uvw07zjynu03dq9rdsrlq
  pubkey: '{"@type":"/ethermint.crypto.v1alpha1.ethsecp256k1.PubKey","key":"A8nbJ3eW9oAb2RNZoS8L71jFMfjk6zVa1UISYgKK9HPm"}'
  mnemonic: ""

$ cronosd keys show test --bech cons
- name: mykey
  type: local
  address: tcrcvalcons1qsklxwt77qrxur494uvw07zjynu03dq9h7rlnp
  pubkey: '{"@type":"/ethermint.crypto.v1alpha1.ethsecp256k1.PubKey","key":"A8nbJ3eW9oAb2RNZoS8L71jFMfjk6zVa1UISYgKK9HPm"}'
  mnemonic: ""
```


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