# Agent Guard – Crypto Address Format Check

> Agent Guard – Crypto Address Format Check is a paid API for AI agents from agent-guard.annushka1190.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Validates whether a given EVM or Solana address is correctly formatted and returns the detected chain type

## Facts

- Endpoint: GET https://agent-guard.annushka1190.workers.dev/v1/address/format-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-guard-crypto-address-format-check-20e71c2a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LLT8xstSJ0iNt0oKCZbhO

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 agent-guard-crypto-address-format-check-20e71c2a
```

Example prompt: Before I send funds, can you check whether '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' is a valid EVM address and confirm which chain it belongs to?

## When to prefer this

Use this endpoint when you need a lightweight, fast check specifically for EVM or Solana address format validity before executing an on-chain transaction or storing a wallet address. Prefer this over general-purpose regex checks because it also detects the chain type and validates EVM checksums (EIP-55). Choose this over full on-chain lookup endpoints when you only need format validation without querying blockchain state.

## Known failure modes

- Missing 'input' query parameter returns a validation error
- Malformed or empty address string may return formatValid:false with no chain detected
- Non-address strings (random text, IBAN, email) may be rejected or return invalid format
- Network timeout on the Cloudflare Workers edge in rare cases
- x402 payment failure if USDC balance or payment header is malformed

## How this service works

Safety and trust layer for AI agents: PII redaction, scam/phishing text scan, EVM/Solana address validation, IBAN checks, JSON repair, deep on-chain wallet risk scoring, x402 counterparty endpoint reputation checks. Free discovery: /openapi.json, /.well-known/x402, /v1/capabilities, /mcp (tools/list). REST + MCP. Pay with USDC via x402 — no API keys.

## Output

Returns a JSON object with two fields: 'chain' (either 'evm' or 'solana') indicating the detected blockchain, and 'formatValid' (boolean) indicating whether the address is correctly formatted and passes checksum rules.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "EVM 0x… or Solana base58 address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-guard-crypto-address-format-check-20e71c2a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-guard.annushka1190.workers.dev](https://www.zero.xyz/host/agent-guard.annushka1190.workers.dev/llms.txt)