> ## Documentation Index
> Fetch the complete documentation index at: https://docs.eco.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Eco for onchain builders

> Integrate cross-chain transfers and destination contract calls into your onchain application.

Use Routes to transfer supported tokens to the chain where your application runs. Add destination calls when fulfillment needs to invoke your contract, such as approving a token and depositing it into a vault.

## Accept a cross-chain contract deposit

Request a custom quote with the calls your destination contract requires. Validate the recipient, token, amount, and encoded calls before funding. The [destination-calls guide](/routes/capabilities/destination-calls) explains the execution context and failure behavior.

The calls execute within the destination fulfillment transaction. Source-chain funding and any later refund are separate transactions, so your application must track the intent lifecycle.

## Choose a deposit-address flow

[Programmable Addresses](/programmable-addresses/overview) provide specific supported deposit routes. Use the Solana flow for Base USDC to a Solana recipient, or the Circle Gateway flow for Gateway deposits. These services are not a general-purpose address that forwards arbitrary assets to any contract.

## Manage application liquidity

Use the [treasury-rebalancing guide](/cookbook/treasury-rebalancing) to plan transfers between your own wallets. Your service chooses thresholds and tracks in-flight transfers before initiating another rebalance.

## Next steps

* [Integrate the Routes API](/get-started/integrate-routes-api) for the transfer workflow.
* [Destination calls](/routes/capabilities/destination-calls) for contract integration.
* [Sauce SDK](/platform/sauce-sdk) for conditional onchain programs.