An AMM you can
read end to end

Constant-product pools: the pool holds a reserve of each asset and prices a swap so their product stays fixed, which is the same shape as the AMMs you already know. What differs is where it runs. Both halves are RIDE contracts on the chain itself, so a swap settles in the same place the balances live.

You do not have to take that on trust, and it is not a claim you should take on trust about any contract. A DecentralChain address carries its chain byte at index 1 of the decoded bytes. Both addresses above decode to 0x3f, which is ?, mainnet. Testnet would be !.

# byte 1 of the base58-decoded address is the chain byte
node -e "const b=require('bs58').decode('3DcZHm89byJjfdkHTJ9m89pyeMk8vChDGtD');console.log(b[1].toString(16))"
# 3f

It is also not published to npm. It resolves inside the monorepo workspace and nowhere else, so an example that installs it will not work outside the repository. The packages page lists the four others in the same position.