# bluepages.fyi Identity & Address Lookup

> bluepages.fyi Identity & Address Lookup is a paid API for AI agents from bluepages.fyi, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Checks whether an Ethereum address or social identity (Twitter handle, email, username) exists in the bluepages database

## Facts

- Endpoint: GET https://bluepages.fyi/check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bluepages-fyi-6f4b301f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_p7LSP7g1V-2b4h6JkX0Z8

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 bluepages-fyi-6f4b301f
```

Example prompt: Can you check if the address 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb1 exists in the bluepages database, and also whether the Twitter handle @vitalikbuterin is listed there?

## When to prefer this

Use this endpoint when you need to check whether a specific Ethereum address or social identity (Twitter, email, username) has a presence in the bluepages web3 identity directory. Prefer this over general blockchain explorers when you want cross-platform identity linkage — i.e. connecting wallet addresses to social handles or emails. Best for identity resolution and verification tasks in web3 contexts.

## Known failure modes

- Missing both address and identity query parameters — returns error indicating one is required
- Payment header missing — returns x402 payment required error with accepted payment details
- Invalid Ethereum address format — may return not found or validation error
- Identity not found in database — returns empty or negative result
- Network or service unavailability — returns 5xx error

## How this service works

Look up cryptocurrency addresses linked to social accounts and curated labels. Paid API service using x402 protocol on Base mainnet.

## Output

Returns whether the queried address or identity exists in the database, along with the types of identities found (e.g. twitter, farcaster, email) and any associated identity records linked to that address or handle.

## 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": [],
     "properties": {
      "address": {
       "type": "string",
       "description": "Cryptocurrency address to check"
      },
      "identity": {
       "type": "string",
       "description": "Username/handle to check (Twitter, email, etc.)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "types": {
       "type": "array",
       "description": "Types of identities found (twitter, farcaster, email)"
      },
      "exists": {
       "type": "boolean",
       "description": "Whether data exists"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "types": [
   "twitter",
   "farcaster"
  ],
  "exists": true,
  "message": "✓ Found in database. Use /data endpoint ($0.05) to get full details."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bluepages-fyi-6f4b301f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bluepages.fyi](https://www.zero.xyz/host/bluepages.fyi/llms.txt)