# Address Label (Base Address Identifier)

> Address Label (Base Address Identifier) is a paid API for AI agents from 402.com.tr, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-15).

Identifies a Base blockchain address by matching it against a curated registry of known protocols, exchanges, bridges, lockers, and burn addresses, then enriches it with on-chain reads for contract type, ERC-4626 vault, Safe multisig, and DEX pool details.

## Facts

- Endpoint: GET https://402.com.tr/api/x402/address-label?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/address-label-base-address-identifier-bfe53fee
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JTLP-O_N-q6B6RlutX_cg

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 address-label-base-address-identifier-bfe53fee
```

Example prompt: Can you tell me what this Base address is — 0x4200000000000000000000000000000000000006? I want to know if it's a known protocol, exchange, vault, or multisig, and what type of contract it is.

## When to prefer this

Choose this endpoint when you need a reliable, sourced label for a Base address and want on-chain type enrichment (vault, multisig, DEX pool, EIP-7702 delegation) in a single call. Prefer it over generic block explorers when you need structured, machine-readable output rather than a human-readable page, or when you need to distinguish contract subtypes programmatically. Ideal for agent pipelines doing transaction monitoring, compliance checks, or user-facing address annotation on Base.

## Known failure modes

- Address not in registry and not a recognizable on-chain type — returned as 'unlabelled' with no label guessed
- Invalid or malformed address string — likely returns an error or empty result
- RPC read failure for on-chain data — partial result or error response
- Address is valid but on a chain other than Base — may return unlabelled or incorrect result
- Rate limiting or payment failure for the x402 micropayment — request blocked

## How this service works

What is this Base address? Matches a sourced registry of known protocol, exchange, bridge, locker and burn addresses (each with the docs/deployments/Basescan source it came from), then reads the chain: contract vs EOA (EIP-7702 delegation shown), ERC-4626 vault (asset()), Safe multisig (getThreshold), DEX pool interface (token0/token1). Unmatched addresses are reported as unlabelled, never guessed.

## Output

Returns a structured label for the queried Base address including: matched entity name and category (protocol, exchange, bridge, locker, burn) with source documentation if known; on-chain classification as contract or EOA (with EIP-7702 delegation if applicable); ERC-4626 vault underlying asset if applicable; Safe multisig threshold if applicable; DEX pool token0/token1 if applicable; or a clear 'unlabelled' status if unmatched — no guessing.

## 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": "Base address to identify"
      }
     }
    }
   },
   "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/address-label-base-address-identifier-bfe53fee/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)