# EVM Chain Health Probe

> EVM Chain Health Probe is a paid API for AI agents from meryol-agenticmarket-x402.hf.space, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-11).

Queries 3 public RPCs in parallel for a given EVM chain and returns median block number, RPC lag, head age, latency, and a 0-100 health score

## Facts

- Endpoint: GET https://meryol-agenticmarket-x402.hf.space/chain/health/:chain?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/meryol-agenticmarket-x402-hf-space-6e09ed41
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dpja7yB1I4olNhzqqbUeS

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 meryol-agenticmarket-x402-hf-space-6e09ed41
```

Example prompt: Before I send this batch of transactions, can you run a liveness check on Base and tell me the health score, block lag between RPCs, and how fresh the chain head is?

## When to prefer this

Use this endpoint when an agent needs to verify chain liveness and RPC consensus before timing a transaction burst, switching RPC providers, or executing any latency-sensitive on-chain operation. Prefer over generic block explorers when you need a quantitative health score and multi-RPC lag comparison in a single call.

## Known failure modes

- Unsupported chain name returns a 400 or validation error — only ethereum, base, arbitrum, optimism are valid
- All 3 RPCs unresponsive returns a low health score with healthy_rpc_count=0
- High lag between RPCs may indicate a chain fork or indexing delay rather than full outage
- Payment not included or invalid returns a 402 response before any chain data is fetched

## How this service works

Checks the health status of a specified blockchain network.

## Output

Returns a JSON object with a 0-100 health score, median block number across 3 RPCs, max lag between RPCs (in blocks), head age (seconds since last block), per-RPC latency, and healthy RPC count — giving a complete picture of chain readiness.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "pathParams": {
   "chain": "ethereum"
  },
  "queryParams": {}
 }
}
```

## 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"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "chain"
     ],
     "properties": {
      "chain": {
       "enum": [
        "ethereum",
        "base",
        "arbitrum",
        "optimism"
       ],
       "type": "string"
      }
     }
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "score_0_100",
      "healthy_rpc_count"
     ]
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/meryol-agenticmarket-x402-hf-space-6e09ed41/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from meryol-agenticmarket-x402.hf.space](https://www.zero.xyz/host/meryol-agenticmarket-x402.hf.space/llms.txt)