Swap Tokens & Bridge Assets

What you’ll build:

Get swap quotes from multiple liquidity sources in a single call
Receive ready-to-sign approve and swap transactions - no separate quote/execute steps
Bridge assets across chains (EVM ↔ EVM, EVM ↔ Solana)

Swap 0.05 ETH → DAI on Ethereum

  Quote 1 (Relay):
    Output:           128.45 DAI
    Min after slip:   125.88 DAI
    Net of fees:      $128.10
    ✅ Transaction ready to sign

  Quote 2 (LI.FI):
    Output:           128.12 DAI
    Min after slip:   125.56 DAI
    Net of fees:      $127.78
    ✅ Transaction ready to sign

Time: ~15 minutes

Prerequisites

A Zerion API key (get one here)
A wallet address with tokens to swap

How it works

Unlike most swap APIs that require separate quote and execute endpoints, the Zerion API combines both into a single call:

Call GET /v1/swap/quotes/ with the sender, recipient, input asset, output asset, and amount
Receive multiple quotes - each includes the expected output, fees, and (when executable) ready-to-sign transaction_approve and transaction_swap payloads
Pick a quote and sign the transactions with your wallet

Quotes are returned best-first, sorted by the fiat value of output_amount_after_fees.

Key parameters

Parameter	Description
`from`	Wallet performing the swap. Must match the chain type of `input[chain_id]` (EVM hex or Solana base58). Required.
`to`	Recipient of the output asset. Must match the chain type of `output[chain_id]`. For a same-chain swap to the same wallet, set equal to `from`. Required.
`input[chain_id]`	Source chain (e.g., `ethereum`, `polygon`, `solana`). Required.
`input[fungible_id]`	Input asset’s fungible ID - either a Zerion fungible ID (e.g., `eth`) or the token contract address. Required.
`input[amount]`	Human-readable input amount as a decimal string (e.g., `"0.05"`), not the smallest unit. Required.
`output[chain_id]`	Destination chain. Defaults to `input[chain_id]` (same-chain swap).
`output[fungible_id]`	Output asset’s fungible ID or token contract address. Required.
`slippage_percent`	Maximum acceptable slippage in percent. Auto-chosen when omitted.
`currency`	Currency for fiat values in the response (e.g., `usd`). Defaults to `usd`.

​Prerequisites

​How it works

​Key parameters

Prerequisites

How it works

Key parameters