# Base RPC Health Map

> Base RPC Health Map is a paid API for AI agents from x402.dailyelo.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns real-time staleness, latency, and error-rate measurements for all major Base public RPC endpoints, polled every 30 seconds in parallel.

## Facts

- Endpoint: GET https://x402.dailyelo.com/v1/rpc/health
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-rpc-health-map-e3ee3ac5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ck8H05i8SqGLjBARoG5kk

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 base-rpc-health-map-e3ee3ac5
```

Example prompt: Can you check the health map for all major Base public RPCs and tell me which ones are the most behind on block height right now, including their latency and error rates?

## When to prefer this

Use this endpoint when you need to know whether a specific Base public RPC is serving a stale chain tip before trusting data read from it — particularly before reading balances, contract state, or transaction receipts where staleness would be undetectable by the caller. Prefer this over generic uptime monitors because it measures block-level lag rather than mere reachability.

## Known failure modes

- Unknown or unlisted RPC host returns empty or 404 response
- Network or upstream timeout causes missing data for some endpoints in the map
- Stale measurement if the 30-second polling cycle is momentarily delayed
- Invalid ?rpc query parameter format returns an error or no results

## How this service works

Which Base public RPCs serve a stale chain tip. Every 30s we ask all major public RPCs for eth_blockNumber in parallel and record how many blocks behind the fastest peer each was, plus latency and error rate. An RPC never reports its own lag, so an agent reading a balance from a lagging endpoint cannot tell. Omit ?rpc for the full map; ?rpc=<host> for one.

## Output

A map of major Base public RPC endpoints, each with: number of blocks behind the fastest peer (measured at the same instant), round-trip latency, and error rate. When querying a specific RPC via ?rpc=<host>, returns the same metrics for just that endpoint. Data is at most 30 seconds old.

## 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",
     "properties": {
      "rpc": {
       "type": "string",
       "description": "optional: RPC url or hostname to look up (omit for the full map)"
      }
     },
     "description": "Which Base RPC endpoints are serving a stale chain tip right now. Every 30s we ask all major public RPCs for eth_blockNumber in parallel (same instant) and record how many blocks behind the fastest peer each one was, plus latency and error rate. Omit ?rpc for the full map; pass ?rpc=<url|hostname> to look up one endpoint. Measurements only, no recommendation."
    }
   },
   "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/base-rpc-health-map-e3ee3ac5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.dailyelo.com](https://www.zero.xyz/host/x402.dailyelo.com/llms.txt)