# agent402.tools B20 Token Verifier

> agent402.tools B20 Token Verifier is a paid API for AI agents from agent402.tools, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Validates whether a given Base address is a genuine factory-issued B20 token by checking the 0xB200 prefix, ERC-20 readability, and registry feature activation

## Facts

- Endpoint: GET https://agent402.tools/api/b20-verify
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-b20-token-verifier-786491f8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wsnhMsDOTFoMg3jWPrHy5

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-tools-b20-token-verifier-786491f8
```

Example prompt: Can you check if 0xB200a3925C282E21C3Ef7b6b700c6f2e19d5c9f3 is a real factory-issued B20 token on Base — I want to know if it has the right prefix, is readable as an ERC-20, and has its B20 features activated in the registry?

## When to prefer this

Use this endpoint when you need to cryptographically and programmatically confirm that a specific Base contract address is a legitimate factory-issued B20 token — especially before integrating, trading, or interacting with an unknown token. Prefer this over manual inspection when you need a structured boolean verdict with specific failure reasons across all three validation axes: address prefix, ERC-20 interface, and registry activation.

## Known failure modes

- Missing or malformed address parameter returns an error
- Address that is not on Base network may fail registry lookup
- Non-contract addresses (EOAs) will fail ERC-20 readability check
- Network connectivity issues to Base RPC may cause lookup failures
- Payment failure (insufficient USDC balance) blocks the call

## How this service works

Boolean verdict with reasons: is this address a real factory-issued B20 on Base? Checks the 0xB200 address prefix, ERC-20 readability, and whether the B20 feature set is activated on the registry. ?address=0x…

## Output

A boolean verdict indicating whether the address is a genuine factory-issued B20 token on Base, accompanied by specific reasons explaining the result — covering the 0xB200 address prefix check, ERC-20 readability, and whether the B20 feature set is activated on the registry.

## 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",
       "description": "0x token address on Base"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "address",
      "isB20",
      "checks"
     ],
     "properties": {
      "isB20": {
       "type": "boolean"
      },
      "checks": {
       "type": "object",
       "properties": {
        "prefixMatch": {
         "type": "boolean"
        },
        "erc20Readable": {
         "type": "boolean"
        },
        "registryActivated": {
         "type": "boolean"
        }
       }
      },
      "address": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "isB20": false,
  "checks": {
   "prefixMatch": false,
   "erc20Readable": true,
   "registryActivated": false
  },
  "address": "0x8335…2913"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-b20-token-verifier-786491f8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)