# SALT19 Base Wallet Balance Lookup

> SALT19 Base Wallet Balance Lookup is a paid API for AI agents from api.salt19.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns the native ETH balance (in ETH and Wei) of a given Ethereum address on the Base network (chain ID 8453)

## Facts

- Endpoint: POST https://api.salt19.com/v1/base-wallet-balance
- 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/salt19-base-wallet-balance-lookup-319f8e31
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZdZpfhDK5fnQM4H6CH1QB

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 salt19-base-wallet-balance-lookup-319f8e31 -d '<json body>'
```

Example prompt: What's the current ETH balance on the Base network for wallet address 0xAbCd1234...? Give me both the ETH amount and the block number it was checked at.

## When to prefer this

Choose this endpoint when you need a fast, pay-per-call native ETH balance check on the Base network (chain 8453) without managing your own RPC infrastructure. Ideal for AI agents operating in the x402 micropayment ecosystem that need real-time balance data before executing on-chain actions. Prefer this over self-hosted RPC calls when you want metered, serverless access via a structured JSON API.

## Known failure modes

- Invalid Ethereum address format (not matching ^0x[0-9a-fA-F]{40}$) returns a validation error
- Address with zero balance returns 0 for both ETH and Wei fields — not an error
- Network unavailability or Base RPC downtime may return a 5xx error
- Payment failure (insufficient USDC for x402 micropayment) blocks the request
- Missing or malformed address field in POST body returns a 400 bad request

## How this service works

SALT19 is an independent applied AI systems lab behind EvoMind governed cognition, the MCP-native Agent Utility Grid, the ARCS research community, AeroClear UAS flight intelligence, and practical software for real-world work.

## Output

Returns a JSON object containing the network identifier (eip155:8453 for Base), the address's ETH balance as a decimal string, the balance in Wei as a string, and the block number at which the balance was read.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "network": "eip155:8453",
  "balance_eth": "0",
  "balance_wei": "0",
  "block_number": 12345678
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/salt19-base-wallet-balance-lookup-319f8e31/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.salt19.com](https://www.zero.xyz/host/api.salt19.com/llms.txt)