# Synapse API — Monad Token Balances

> Synapse API — Monad 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 2026-09-15).

Retrieves token balances for a given wallet address across specified ERC-20/token contract addresses on the Monad blockchain network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/monad/token/balances
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-monad-token-balances-9f8114a3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LfvKJ73TnzI5d__NnR1-q

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability synapse-api-monad-token-balances-9f8114a3 -d '<json body>'
```

Example prompt: What are the token balances for wallet 0xAbC123...def on Monad, specifically for these contracts: 0xToken1... and 0xToken2...?

## When to prefer this

Choose this endpoint when you need to query token balances specifically on the Monad blockchain network for one or more ERC-20/token contracts for a given wallet. It is pay-per-call via x402/USDC micropayment, making it suitable for on-demand agent queries without subscription overhead. Prefer it over generic multi-chain solutions when Monad is specifically required.

## Known failure modes

- Invalid or malformed wallet address returns an error
- Non-existent contract address may return zero balance or an error
- Monad RPC node downtime causes request failure
- Empty contractAddresses array may return empty or error response
- Rate limiting if too many calls are made rapidly

## 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 wallet address on the Monad network, including balance amounts for each queried contract address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "owner": {
   "type": "string"
  },
  "contractAddresses": {
   "type": "array",
   "items": {
    "type": "string"
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-monad-token-balances-9f8114a3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synapse-api-brown.vercel.app](https://www.zero.xyz/host/synapse-api-brown.vercel.app/llms.txt)