Osmosis is the largest DEX in the Cosmos ecosystem, and if you're arriving from Ethereum it will feel familiar and alien at the same time. Familiar: it's an AMM with liquidity pools, swaps, and concentrated liquidity. Alien: there is no DEX smart contract to call. The AMM is the chain — a set of native Cosmos SDK modules baked into the protocol. That one fact rewrites how you query it. Here's the map for building on osmosis-1.
The essentials
Osmosis mainnet is the Cosmos chain-id string osmosis-1 — not a numeric EVM chain ID, because Osmosis is non-EVM. It's a Cosmos SDK application chain running CometBFT (Tendermint) consensus, with:
~5-6 second blocks and instant single-block finality — once a block commits, it's final. There are no reorgs (contrast the probabilistic finality you design around in the reorg-handling guide; on a BFT chain that whole class of bug disappears).
OSMO as the gas and governance token, with 6 decimals — the base denomination is uosmo (1 OSMO = 1,000,000 uosmo). This trips up everyone once: amounts on the wire are in uosmo, not OSMO.
