# 402.com.tr B20 Token Metadata Reader

> 402.com.tr B20 Token Metadata Reader is a paid API for AI agents from 402.com.tr, paid per call via x402, $0.04/call, status unknown (last checked 2026-09-14).

Reads on-chain metadata for a B20 token including name, symbol, mutability status, and rename history to detect impersonation or bait-and-switch risks

## Facts

- Endpoint: GET https://402.com.tr/api/x402/b20-metadata
- Price: $0.04/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/402-com-tr-b20-token-metadata-reader-bb40ff5a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QeoOVT6BnAcpDrFJ4a0CM

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 402-com-tr-b20-token-metadata-reader-bb40ff5a
```

Example prompt: Can you check the metadata for B20 token at address 0xAbC123... on Base — specifically whether its name or symbol has ever been changed on-chain and whether anyone holds the METADATA_ROLE that could rename it again?

## When to prefer this

Use this endpoint when you need to verify the identity integrity of a B20 token on Base — specifically to check if its name/symbol have changed since launch (bait-and-switch risk) or if a METADATA_ROLE holder exists who could rename it in the future. Prefer this over generic ERC-20 metadata calls when auditability of rename history and mutability status is required.

## Known failure modes

- Invalid or missing token address returns an error
- Non-B20 ERC-20 address may return partial or empty metadata
- Network errors or RPC unavailability may cause timeouts
- Address that is not a contract returns an error or empty result

## How this service works

🆕 A B20 with a METADATA_ROLE holder can call updateName/updateSymbol — change its own identity after launch (an impersonation / bait-and-switch vector ERC-20 has no protocol equivalent for). Reads whether the metadata is mutable (role holder exists) AND whether it has ALREADY been renamed on-chain (NameUpdated/SymbolUpdated history). Trust the address, not the label.

## Output

Returns the current name and symbol of the B20 token, whether the metadata is mutable (presence of a METADATA_ROLE holder), and the full on-chain history of NameUpdated and SymbolUpdated events so the agent can detect if the token has ever been renamed since deployment.

## 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"
    },
    "pathParams": {
     "type": "object"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "B20 token address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402-com-tr-b20-token-metadata-reader-bb40ff5a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402.com.tr](https://www.zero.xyz/host/402.com.tr/llms.txt)