Chain ID

A chain ID is a unique identifier that represents a blockchain network. We use it to distinguish different blockchain networks from each other and to ensure that transactions and messages are sent to the correct network. Evmos network follows the format of identifier_EIP155-version format.

Official Chain IDs

tip

NOTE: The latest Chain ID (i.e highest Version Number) is the latest version of the software and mainnet. Also note, that the following upgrades technically did not require a Chain ID change:

• evmos_9001-1 -> evmos_9001-2
• evmos_9000-3 -> evmos_9000-4

Mainnet

Name	Chain ID	Identifier	EIP155 Number	Version Number	Active
DEP 2	evmos_9001-2	evmos	9001	2	✅
DEP 1	evmos_9001-1	evmos	9001	1	🚫

Testnet

Name	Chain ID	Identifier	EIP155 Number	Version Number	Active
DEP Public Testnet	evmos_9000-4	evmos	9000	4	✅
DEP Public Testnet	evmos_9000-3	evmos	9000	3	🚫
Olympus Mons Incentivized Testnet	evmos_9000-2	evmos	9000	2	🚫
Arsia Mons Testnet	evmos_9000-1	evmos	9000	1	🚫

tip

You can also lookup the EIP155 Chain ID by referring to chainlist.org.

The Chain Identifier

Every chain must have a unique identifier or chain-id. Tendermint requires each application to define its own chain-id in the genesis.json fields. However, in order to comply with both EIP155 and Cosmos standard for chain upgrades, Evmos-compatible chains must implement a special structure for their chain identifiers.

Structure

The DEP Chain ID contains 3 main components

• Identifier: Unstructured string that defines the name of the application.
• EIP155 Number: Immutable EIP155 CHAIN_ID that defines the replay attack protection number.
• Version Number: Is the version number (always positive) that the chain is currently running. This number MUST be incremented every time the chain is upgraded or forked in order to avoid network or consensus errors.

Format

The format for specifying and DEP compatible chain-id in genesis is the following:

{identifier}_{EIP155}-{version}

The following table provides an example where the second row corresponds to an upgrade from the first one:

ChainID	Identifier	EIP155 Number	Version Number
evmos_9000-1	evmos	9000	1
evmos_9000-2	evmos	9000	2
...	...	...	...
evmos_9000-N	evmos	9000	N