# Blockscout Metadata API – Address Tag Lookup

> Blockscout Metadata API – Address Tag Lookup is a paid API for AI agents from api.blockscout.com, paid per call via x402, $0.012/call, status unknown (last checked 2026-09-14).

Retrieves on-chain metadata tags (labels, contract names, dapp info) for one or more blockchain addresses across multiple chains via Blockscout's metadata service

## Facts

- Endpoint: GET https://api.blockscout.com/services/metadata/api/v1/metadata
- Price: $0.012/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockscout-metadata-api-address-tag-lookup-67fb40b9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uF9vJV149wE_vwjCBrI8m

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 blockscout-metadata-api-address-tag-lookup-67fb40b9
```

Example prompt: Can you look up the Blockscout metadata tags for the address 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984 on Ethereum (chainId 1) and tell me what labels or dapp associations it has?

## When to prefer this

Use this endpoint when you need to enrich or label specific blockchain addresses with human-readable metadata (names, dapp associations, tag categories) across multiple chains. It is especially useful for displaying contract labels in UIs, screening addresses for known protocols, or resolving anonymous addresses to known entities. Prefer this over raw chain RPC calls when you want curated, cross-chain metadata rather than raw contract bytecode or transaction history.

## Known failure modes

- Invalid or malformed address returns empty or null entry for that address
- Unsupported chainId may return no results or an error
- Missing required 'type' or 'method' fields returns a validation error
- Rate limiting or payment failure (x402) blocks the request
- Very high tagsLimit values may be silently capped or cause slower responses

## How this service works

Explore crypto activities with Blockscout's multichain search. Find transactions, addresses, tokens, and dapps across top blockchain networks — your go-to explorer for cross-chain blockchain data

## Output

Returns a JSON object with an 'addresses' map, where each key is a queried address and the value contains associated metadata tags — such as contract name, dapp label, tag type, and chain-specific annotations — sourced from Blockscout's curated metadata 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "chainId": {
       "type": "string"
      },
      "tagTypes": {
       "type": "string"
      },
      "addresses": {
       "type": "string"
      },
      "tagsLimit": {
       "type": "integer"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "addresses": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blockscout-metadata-api-address-tag-lookup-67fb40b9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.blockscout.com](https://www.zero.xyz/host/api.blockscout.com/llms.txt)