ICS20

Overview

The ICS20 precompile exposes standardized IBC fungible token transfer logic to EVM contracts. Initiate cross-chain token transfers, query IBC denominations (denom, denoms, denomHash), and build composable cross-chain payment flows — all from Solidity. Precompile Address: 0x0000000000000000000000000000000000000802

Gas Costs

Method Type	Gas Cost
Transactions	`2000 + (30 x bytes of input)`
Queries	`1000 + (3 x bytes of input)`

Transaction Methods

Method	Signature	Returns
`transfer`	`transfer(string sourcePort,string sourceChannel,string denom,uint256 amount,address sender,string receiver,Height timeoutHeight,uint64 timeoutTimestamp,string memo)`	`(uint64 nextSequence)`

Query Methods

Method	Signature	Returns
`denom`	`denom(string hash)`	`(Denom denom)`
`denomHash`	`denomHash(string trace)`	`(string hash)`
`denoms`	`denoms(PageRequest pageRequest)`	`(Denom[] denoms, PageResponse pageResponse)`

Example

// Pseudocode: import ICS20I and construct Height timeoutHeight per the ABI reference.
ICS20I constant ics20 = ICS20I(0x0000000000000000000000000000000000000802);

// Transfer this contract's tokens to another chain
ics20.transfer(
    "transfer",            // source port
    "channel-0",           // source channel
    "ctm",                 // denomination
    1000000,               // amount
    address(this),         // sender: must be the direct caller
    receiver,               // receiver on destination chain
    timeoutHeight,
    uint64((block.timestamp + 600) * 1e9), // timeout: absolute Unix time in nanoseconds (IBC v1 channel)
    ""                     // memo
);

sender must be the direct caller of the precompile. A contract can send only its own tokens, so it passes address(this); an EOA calls the precompile directly with its own address. Any other address reverts with msg.sender address ... does not match the requester address .... For a channel-N (IBC v1) source channel, timeoutTimestamp is an absolute Unix time in nanoseconds, not seconds. For an IBC v2 client ID, the precompile passes the value through unchanged and IBC v2 reads it in seconds.

Trust Model

ICS20 transfers inherit IBC’s trust-minimized model:

No trusted intermediary required
Safety backed by light-client verification on both chains
Timeouts refund the sender after a relayer submits a timeout proof. Refunds depend on a live relayer and an active counterparty light client; if the client expires or is frozen, the refund waits until the client is recovered (for example through a governance client-recovery proposal)

For exact params, events, and return values, see Precompile ABI Reference.

Learn

Core Concepts

Chain Architecture

Execution and EVM

Interoperability and IBC

Modules & Precompiles

Transaction Lifecycle

Overview

Gas Costs

Transaction Methods

Query Methods

Example

Trust Model

​Overview

​Gas Costs

​Transaction Methods

​Query Methods

​Example

​Trust Model

Overview

Gas Costs

Transaction Methods

Query Methods

Example

Trust Model