# Agent402 Bitcoin Address Validator

> Agent402 Bitcoin Address Validator is a paid API for AI agents from agent402.co.uk, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Validates Bitcoin address format and checksum for Base58Check (legacy/P2SH) and bech32/bech32m (native SegWit/Taproot) addresses without performing any on-chain UTXO lookup.

## Facts

- Endpoint: POST https://agent402.co.uk/v1/validate/btc-address
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-bitcoin-address-validator-c93262c7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-68ZRcBpluscQkxdEBVX9

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 agent402-bitcoin-address-validator-c93262c7 -d '<json body>'
```

Example prompt: Before I withdraw, check whether this Bitcoin address is structurally valid: bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq — tell me if it passes checksum and what type it is.

## When to prefer this

Use this endpoint when you need a cheap ($0.001), fast, offline-style structural and checksum validation of a Bitcoin address before initiating a payment or withdrawal. Prefer this over on-chain lookups when you only need to confirm the address is well-formed (not whether it has funds or has been used). It handles all major Bitcoin address formats: legacy Base58Check (1xxx, 3xxx), native SegWit bech32 (bc1q), and Taproot bech32m (bc1p).

## Known failure modes

- Malformed or unsupported address format returns valid=false
- Non-Bitcoin addresses (Ethereum, Solana, etc.) are not recognized and will fail or return invalid
- Ambiguous or truncated addresses may return invalid
- Network errors may cause the endpoint to be temporarily unreachable

## How this service works

Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.

## Output

Returns a JSON object with a 'valid' boolean, an 'type' field indicating the address type (e.g. p2wpkh, p2pkh, p2sh, p2tr), and a 'chain' field (e.g. 'btc' or testnet equivalent). No on-chain state or UTXO balance is checked — purely structural and checksum validation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string",
   "description": "BTC address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "p2wpkh",
  "chain": "btc",
  "valid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-bitcoin-address-validator-c93262c7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.co.uk](https://www.zero.xyz/host/agent402.co.uk/llms.txt)