# Blockchain Chain Facts Lookup

> Blockchain Chain Facts Lookup is a paid API for AI agents from payments-intel-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18).

Returns canonical chain metadata (CAIP-2 ID, gas token, finality class, block explorer, x402/MPP settlement support, and stablecoins) for a named or identified blockchain

## Facts

- Endpoint: GET https://payments-intel-production.up.railway.app/v1/chain?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockchain-chain-facts-lookup-e359b1f4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-Xz6ImKH-u2WH1TKDSRTP

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 blockchain-chain-facts-lookup-e359b1f4
```

Example prompt: What are the chain facts for Base — its CAIP-2 ID, gas token, block explorer, whether it supports x402 and MPP settlement, and which stablecoins are available on it?

## When to prefer this

Use this endpoint when an agent needs to resolve authoritative chain metadata — especially CAIP-2 IDs, x402/MPP settlement eligibility, or stablecoin availability — from a single curated lookup rather than scraping documentation or relying on stale hardcoded values. Particularly valuable in payment routing flows where knowing whether a chain supports x402 or MPP before initiating a transaction avoids failed payment attempts.

## Known failure modes

- Unknown chain slug or name returns 404 with no charge
- Malformed input (e.g. invalid CAIP-2 format) returns 400 with no charge
- Fields without verified data return the string 'unknown' rather than an error
- Chain not yet indexed in dataset returns 404

## How this service works

What are the basic facts of this chain (CAIP-2 id, gas token, explorer, x402/MPP settlement, stablecoins)? Cited chain facts from a prepared dataset: CAIP-2 chain id, gas token, finality class, block explorer, whether x402 and MPP settle there, and stablecoins. Fields not established from a source are the string "unknown". Unknown chains and malformed input return 404/400 and are never charged.

## Output

A structured record containing: the canonical CAIP-2 chain ID, the native gas token symbol, the finality class (e.g. fast/probabilistic), the block explorer URL, boolean flags for x402 and MPP settlement support, and a list of supported stablecoins. Fields not sourced from a verified dataset return the string 'unknown'. Unknown or malformed chain identifiers return 404 or 400 respectively with no charge.

## 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": [
      "chain"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "Chain slug, name or CAIP-2 id, e.g. base, solana, eip155:8453"
      }
     }
    }
   },
   "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/blockchain-chain-facts-lookup-e359b1f4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from payments-intel-production.up.railway.app](https://www.zero.xyz/host/payments-intel-production.up.railway.app/llms.txt)