# Northline ChainKit USDC Balance Lookup

> Northline ChainKit USDC Balance Lookup is a paid API for AI agents from northline-chainkit.northline-c86.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Fetches USDC token balances for a given Ethereum-compatible wallet address across Base and Arc chains.

## Facts

- Endpoint: GET https://northline-chainkit.northline-c86.workers.dev/v1/usdc/balances?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/northline-chainkit-usdc-balance-lookup-ba5efc0c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fsAxDQKeVHeCUENsa5EGT

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 northline-chainkit-usdc-balance-lookup-ba5efc0c
```

Example prompt: What's the USDC balance for wallet 0x4A3B2C1D0E9F8A7B6C5D4E3F2A1B0C9D8E7F6A5B on Base and Arc?

## When to prefer this

Use this endpoint when you need real-time USDC balances for a specific wallet address across both Base and Arc chains in a single call. Prefer this over generic block explorers when you want a pay-per-use, structured JSON response with cross-chain aggregation and no API key setup — especially in agentic workflows using the x402 micropayment protocol.

## Known failure modes

- Invalid or malformed wallet address (not matching ^0x[0-9a-fA-F]{40}$) returns a validation error
- Missing required 'address' query parameter results in a 400-level error
- Payment not fulfilled (x402 payment required) results in a 402 response before data is returned
- Wallet address exists but holds zero USDC — balances may return 0.00 for one or both chains
- Chain-specific RPC outage may cause partial or failed responses for one chain

## How this service works

x402 pay-per-call onchain API (Base + Arc).

## Output

Returns a JSON object containing a list of USDC balances per chain, e.g. [{"usdc":"8.29","chain":"base"},{"usdc":"0.44","chain":"arc"}]. Each entry specifies the USDC amount as a decimal string and the chain name.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "balances": [
   {
    "usdc": "8.29",
    "chain": "base"
   },
   {
    "usdc": "0.44",
    "chain": "arc"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/northline-chainkit-usdc-balance-lookup-ba5efc0c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from northline-chainkit.northline-c86.workers.dev](https://www.zero.xyz/host/northline-chainkit.northline-c86.workers.dev/llms.txt)