# Synapse API — Katana Token Balances

> Synapse API — Katana 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 2026-09-13).

Fetches token balances for a given wallet owner address across specified ERC-20 or native token contract addresses on the Katana network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/katana/token/balances
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-katana-token-balances-3cc8874c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_W3OtyuTbJQWKfWGXDwn3f

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-katana-token-balances-3cc8874c -d '<json body>'
```

Example prompt: Check the token balances for wallet 0xAbC123...def456 on Katana, specifically for these contract addresses: 0xToken1... and 0xToken2....

## When to prefer this

Use this endpoint when you need on-chain token balance data specifically on the Katana network for one or more ERC-20 token contracts for a given wallet address. Prefer this over generic blockchain explorers when you need programmatic, pay-per-call access with no API key setup, or when integrating into an agent that pays via x402 USDC micropayments.

## Known failure modes

- Invalid owner address format returns an error
- Invalid or non-existent contract address returns zero balance or an error
- Empty contractAddresses array may return an empty result set
- Network timeout if the Katana RPC node is slow or unavailable
- Payment failure if x402 USDC payment of $0.01 is not processed correctly

## 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 owner wallet address, one entry per contract address provided, including token amounts and possibly token metadata such as symbol and decimals.

## 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-katana-token-balances-3cc8874c/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)