01Cosmos app chain
Launch a Cosmos app chain. MetaMask and Keplr both work on day one.
A Cosmos app chain is a blockchain of your own, built with the Cosmos SDK: your coin pays the fees, your validators make the blocks and your holders vote on changes. Ours runs Cosmos EVM, so Solidity contracts and MetaMask work next to Keplr, and it goes live in about 30 minutes.
Updated . Prices checked .
- From $249 one-time
- Your own validators
- Your keys, not ours
ok genesis written: 1,000,000,000 BLK, 7 percent a year
ok 4 validators signed their genesis stake
ok block 1 committed by 4 of 4
ok Keplr: addresses start blk1
ok MetaMask: EVM JSON-RPC answering
.. IBC channel to Osmosis (bridge add-on)
height 48,213
On this pageWhat you get
02What you get
One chain, two kinds of wallet.
Most Cosmos chains only speak to Cosmos wallets. Cosmos EVM adds the engine that runs Ethereum smart contracts, so the same coin and the same accounts work in both worlds.
IBC needs a relayer, a small program that carries messages between chains. The bridge add-on sets it up and runs it.
Solidity can stake and vote
Cosmos EVM gives contracts fixed addresses that reach the chain's own modules. A contract can delegate stake, claim rewards, vote or send coins over IBC.
| Module | Address |
|---|---|
| Staking | 0x…0800 |
| Rewards | 0x…0801 |
| IBC transfer | 0x…0802 |
| Bank | 0x…0804 |
| Governance | 0x…0805 |
From the Cosmos EVM precompile list, checked October 2026. Fees follow EIP-1559, but the base fee goes to validators and stakers instead of being burned.
03Launch steps
How a Cosmos chain launches, step by step.
The Cosmos docs describe the same path for every new chain. Here is each step, what it takes by hand, and who does it when you launch here.
Step 1
Name the chain
A chain ID like blockcoin-1, a coin unit like ublk and an address prefix like blk. Wallets use all three to tell your chain apart.
Here: three fields in the builder, with checks.
Step 2
Write the genesis file
The genesis file is the chain's first page: total supply, who holds it, yearly inflation and the unstaking period.
Here: you pick the numbers, we write the file. Starting coins can go to your Keplr address.
Step 3
Collect validator signatures
Each first validator signs a genesis transaction (a gentx) that stakes its coins. All of them go into the file before block 1.
Here: done for your 4 or more validators, on servers you log in to.
Step 4
Start the validators together
The validators find each other and start making blocks once more than two thirds of the stake is online.
Here: automatic. The chain is live in about 30 minutes.
Step 5
Connect other chains
IBC is built in, but a relayer has to carry the messages, and someone has to keep it funded and running.
Here: the bridge add-on sets up and hosts it.
Step 6
Get into wallets and apps
Any site can ask Keplr to add your chain. To appear in apps by default, you open a pull request to the Cosmos chain registry.
Yours: the registry listing. Its daily checks drop endpoints that keep failing.
Sources: Cosmos SDK run a node, IBC docs, Keplr suggest chain, Cosmos chain registry, checked October 2026.
04Security
Renting the Hub's validators is over. Bring your own.
Until 2026, a new chain could borrow the Cosmos Hub's validators through Interchain Security. Hub holders voted to end it. Every new Cosmos chain now runs its own validator set.
20 Feb 2026
Removal proposed
A Cosmos forum post said Interchain Security found no product market fit and slowed the Hub down.
10 Mar 2026
New consumer chains blocked
Proposal 1025, the Gaia v27 upgrade, passed.
1 Sep 2026
Interchain Security removed
Proposal 1052, the Gaia v28 upgrade, passed.
What it means for you
Start with 4 validators: the chain keeps going with one offline. Seven survive two. Five and six add cost but no extra safety.
Pick a count
The proof of stake page has a calculator for 4 to 10 validators with the monthly hosting.
Outside validators later
Anyone with your coin can stake and join the set. Rewards and commission are in the Cosmos validator guide.
05Your settings
Six choices, safe defaults.
The builder starts on the values below, marked Recommended. Change any of them before launch. After launch, holders can change most rules by an on-chain vote.
| Setting | Default | What it does |
|---|---|---|
| Chain ID | blockcoin-1 | Your network's name tag. The number goes up after a major upgrade. |
| Coin unit | ublk | The smallest unit. One BLK is a million ublk. |
| Address prefix | blk | Keplr addresses start blk1. MetaMask shows the same account as 0x. |
| Total supply | 1,000,000,000 | Coins created in the genesis file. |
| Yearly inflation | 7 percent | New coins paid to stakers each year. 0 to 20. |
| Unstaking period | 21 days | How long staked coins take to unlock. 1 to 28. |
Changed by vote
Governance is on. Holders and validators vote on proposals, and a passed vote can change parameters or schedule an upgrade without a hard fork fight.
Penalties stay standard
Slashing uses the Cosmos SDK defaults: 5 percent for double signing, 1 percent and a 10 minute jail for long downtime.
06The code underneath
Open source, actively released.
Cosmos SDK
v0.55.0, 28 Jul 2026
Staking, governance, bank. Apache-2.0.
Cosmos EVM
v0.7.3, 3 Sep 2026
Solidity, MetaMask, JSON-RPC. Apache-2.0.
ibc-go
v11.2.0, 15 Jul 2026
Links to other chains over IBC.
Latest releases read from each project's GitHub page in October 2026.
07Price
What a Cosmos app chain costs.
One price for the chain, then hosting per server each month. The builder shows the total before you pay.
Cosmos chain, one-time
$249
The chain build, genesis and launch, on 4 or more validators.
Hosting after launch: $19 per server a month.
Worked example: 4 validators with a block explorer, a web wallet and a faucet
$249 + $149 + $149 + $79 = $626 one-time. Hosting 7 servers x $19 = $133 a month.
What agencies quote
A 2026 agency roundup puts a custom Cosmos SDK chain at $80,000 to $250,000. Managed services such as Zeeve publish no price. Checked October 2026.
Add-ons
Block explorer $149, web wallet $149, faucet $79, swap $599, bridge with IBC relayer $999. Add them now or later.
08Clear lines
Your chain, your vote. We run the servers.
Yours
- The chain, its coin and its rules
- The server logins: we never hold your private keys
- The starting coins and the first stake
- Every governance vote after launch
Not included
- Outside validators or stakers: those are yours to win
- Your chain registry pull request
- Exchange listings or a price for your coin
09Questions
Cosmos app chain: questions
Short answers before you launch.
What is a Cosmos app chain?
A blockchain built with the Cosmos SDK for one project. It has its own coin, its own validators and its own rules, and it can link to other Cosmos chains over IBC. The appchain guide compares it with layer 2 rollups.
How do I create a Cosmos blockchain?
Name it, write a genesis file with the supply and staking rules, have at least four validators sign their stake, then start them together. Here, you set the names and numbers in the builder and the chain is live in about 30 minutes.
Can I still use Interchain Security?
No. Cosmos Hub holders blocked new consumer chains in March 2026 and removed Interchain Security in September 2026. New chains run their own validators.
Does it work with MetaMask?
Yes. Our Cosmos chains run Cosmos EVM, which answers the same JSON-RPC calls as Ethereum. MetaMask, Hardhat and Foundry work, and Keplr works for the same accounts.
How do I connect to Osmosis or the Cosmos Hub?
Over IBC, which is built in. A relayer has to carry the messages; the bridge add-on sets it up and hosts it.
How much does a Cosmos app chain cost?
$249 one-time for the chain on 4 validators, plus $19 per server a month. Add-ons start at $79.
Will my chain show up in Keplr?
Any website can ask Keplr to add it, and the user approves. To be listed by default in Cosmos apps, you add your chain to the Cosmos chain registry with a pull request.
Your coin. Your validators. Your vote.
A Cosmos app chain with MetaMask and Keplr support, from $249 one-time.