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Synapse API — Token Balances by Owner
x402
Synapse API — Token Balances by Owner 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 2026-09-13).
Returns token balances for a given wallet address across one or more ERC-20 contract addresses on supported blockchain networks
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 the token balances held by the specified owner wallet for each of the provided contract addresses, including amounts per token contract, enabling portfolio visibility and on-chain asset verification.
Example use cases
DeFi portfolio snapshot for a wallet
“Pull the token balances for wallet 0x1234...abcd for USDC (0xA0b8...eB48) and WETH (0xC02a...6Cc2) so I can see what they're holding.”
Verify token holdings before airdrop
“Check whether wallet 0xDEAD...BEEF holds any tokens from contract 0xToken...CA11 — I need to confirm eligibility before we do the airdrop.”
Monitor whale wallet token positions
“What token balances does the wallet 0xWhale...F00D have across these five contract addresses: 0xAAA..., 0xBBB..., 0xCCC..., 0xDDD..., 0xEEE...?”
Technical details
Endpoint
POSThttps://synapse-api-brown.vercel.app/api/adi/token/balancesWhen to prefer
Choose this endpoint when you need fast, pay-per-call token balance lookups for one or more ERC-20 contracts on a specific wallet address without managing your own blockchain node infrastructure. It is well-suited for AI agents needing on-demand DeFi portfolio checks, airdrop eligibility verification, or whale monitoring across multiple tokens in a single call.
Side effects
- Invalid owner address format returns an error or empty result
- Unsupported contract address or network returns zero or null balance
- Rate limiting or payment failure (x402) blocks the call
- Network congestion may delay RPC response
- Contract addresses not on a supported chain return no data
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| owner | string | |
| contractAddresses | array |
Tags
x402
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