# Semilla1 Lab txcheck - Token Balances

> Semilla1 Lab txcheck - Token Balances is a paid API for AI agents from semilla1-txcheck.netlify.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-28).

Returns token balances for a given EVM address on Base, checking USDC, WETH, cbETH, and other major Base tokens.

## Facts

- Endpoint: GET https://semilla1-txcheck.netlify.app/tokens?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/semilla1-lab-txcheck-token-balances-4b7942d9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bNL9n_XlmgDLBzDlitg0_

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 semilla1-lab-txcheck-token-balances-4b7942d9
```

Example prompt: What tokens does wallet 0xa4ba7f4FCA58C50df7232BA65E8D794F78Dc65bc hold on Base? Check for USDC, WETH, and other major tokens.

## When to prefer this

Choose this endpoint when you need to quickly check which major Base-ecosystem tokens a specific EVM wallet holds, especially when you want a pre-curated list of top Base tokens (USDC, WETH, cbETH, AERO, BRETT, etc.) checked in a single call rather than querying individual token contracts. Best for portfolio lookups, pre-payment balance verification, and airdrop monitoring on Base.

## Known failure modes

- Invalid or malformed EVM address (not matching ^0x[0-9a-fA-F]{40}$) returns an error
- Address has no token balances — returns empty tokens array
- RPC or Base node connectivity issues may cause delayed or failed responses
- Payment not included or insufficient — x402 payment of 0.005 USDC required per call

## How this service works

Resumen de una transacción de Base: estado, gas, transferencias USDC. Pago x402 v2: 0.01 USDC en Base (lote de hasta 10: 0.05 USDC; /balance, /tokens, /receipt: 0.005 USDC).

## Output

Returns a JSON object with the queried address, a list of tokens checked (USDC, USDbC, WETH, cbETH, wstETH, cbBTC, DAI, EURC, AERO, VIRTUAL, DEGEN, BRETT), and for each token with a non-zero balance: the token symbol, contract address, decimal precision, raw balance string, and human-readable amount.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Dirección EVM (0x + 40 hex)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "address",
      "tokens",
      "checked"
     ],
     "properties": {
      "tokens": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "symbol",
         "token",
         "raw",
         "decimals",
         "amount"
        ],
        "properties": {
         "raw": {
          "type": "string"
         },
         "token": {
          "type": "string"
         },
         "amount": {
          "type": "number"
         },
         "symbol": {
          "type": "string"
         },
         "decimals": {
          "type": "integer"
         }
        }
       }
      },
      "address": {
       "type": "string"
      },
      "checked": {
       "type": "array",
       "items": {
        "type": "string"
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "tokens": [
   {
    "raw": "2000000",
    "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": 2,
    "symbol": "USDC",
    "decimals": 6
   }
  ],
  "address": "0xa4ba7f4FCA58C50df7232BA65E8D794F78Dc65bc",
  "checked": [
   "USDC",
   "USDbC",
   "WETH",
   "cbETH",
   "wstETH",
   "cbBTC",
   "DAI",
   "EURC",
   "AERO",
   "VIRTUAL",
   "DEGEN",
   "BRETT"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/semilla1-lab-txcheck-token-balances-4b7942d9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from semilla1-txcheck.netlify.app](https://www.zero.xyz/host/semilla1-txcheck.netlify.app/llms.txt)