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Synapse API — Ethereum Token Balances
x402
Synapse API — Ethereum Token Balances is a paid API for AI agents from synapse-api-brown.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).
Retrieves ERC-20 token balances for a given Ethereum wallet address, optionally filtered to specific contract addresses
Price / call$0.01
Success—
StatusUnknown
How this service works
High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.
Output
Returns a list of token balances for the specified Ethereum wallet address, each entry indicating the token contract address and the corresponding balance amount held by the owner. If specific contract addresses are provided, results are filtered to those tokens only.
Example use cases
DeFi portfolio snapshot
“What ERC-20 tokens does the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 currently hold, and what are their balances?”
Verify token receipt on Ethereum
“Can you confirm whether wallet 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B has received any USDT at contract 0xdAC17F958D2ee523a2206206994597C13D831ec7?”
Multi-token balance audit
“Pull the balances for DAI at 0x6B175474E89094C44Da98b954EedeAC495271d0F and WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 for the wallet 0x742d35Cc6634C0532925a3b844Bc454e4438f44e.”
Technical details
Endpoint
POSThttps://synapse-api-brown.vercel.app/api/ethereum/token/balancesWhen to prefer
Choose this endpoint when you need to look up ERC-20 token balances on the Ethereum mainnet for one or more wallet addresses. It is especially useful for DeFi portfolio tracking, verifying token transfers, and auditing holdings across specific contracts. It covers Ethereum specifically, so prefer it over generic multi-chain endpoints when Ethereum is the target network.
Side effects
- Invalid Ethereum address format returns an error
- Non-existent or zero-balance tokens may return empty results
- Rate limiting or payment failure via x402 protocol blocks the request
- Network timeouts if Ethereum RPC is slow
- Contract addresses that are not valid ERC-20 tokens may return errors or empty balances
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| owner | string | |
| contractAddresses | array |
Tags
x402
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