# HALOWERK kettenwerk Chain Health Check

> HALOWERK kettenwerk Chain Health Check is a paid API for AI agents from kette.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-12).

Queries multiple public RPC endpoints for specified EVM chains in parallel and compares block height and block hash to detect lagging, forked, or divergent nodes

## Facts

- Endpoint: POST https://kette.halowerk.com/chain/health?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-kettenwerk-chain-health-check-f7094ec0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h2oCwLTLXZf-NTr9i6XFr

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 halowerk-kettenwerk-chain-health-check-f7094ec0 -d '<json body>'
```

Example prompt: Check the health of the Base and Ethereum RPC endpoints right now — query at least three nodes for each chain and tell me if any of them are lagging behind or serving a different block hash than the others.

## When to prefer this

Choose this endpoint when you need to verify that public RPC endpoints for EVM-compatible chains are in consensus — especially before signing transactions, deploying contracts, or trusting on-chain reads from a single provider. It is uniquely suited for detecting node lag, fork divergence, and stale state by comparing multiple nodes in parallel rather than trusting any single RPC source.

## Known failure modes

- Invalid chain name not in allowed enum returns validation error
- All public RPC endpoints for a requested chain are temporarily unavailable
- Timeout if RPC endpoints are slow to respond under network congestion
- Requesting more than 6 chains in a single call returns schema error
- Ambiguous results if all queried nodes happen to be on the same divergent fork

## How this service works

Queries every public RPC endpoint this hub knows for a chain in parallel — at least three, usually five — and reports what each one says instead of trusting one. Disagreement is the valuable finding: a single endpoint that lags or serves a different fork is exactly the failure mode this endpoint is built to expose, so agreement is reported per endpoint and the tolerance in blocks is derived from that chain's block time and stated. Beyond height it compares the actual block hash six blocks deep a

## Output

Returns per-endpoint block height and block hash data for each queried chain, reports consensus agreement or disagreement among nodes, identifies any endpoints that are lagging or serving a different fork, and states the block tolerance threshold derived from each chain's block time.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chains": {
   "type": "array",
   "items": {
    "enum": [
     "ethereum",
     "base",
     "arbitrum",
     "optimism",
     "polygon",
     "bsc"
    ],
    "type": "string"
   },
   "default": [
    "base"
   ],
   "maxItems": 6,
   "minItems": 1,
   "description": "Chains to check. Defaults to base."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-kettenwerk-chain-health-check-f7094ec0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kette.halowerk.com](https://www.zero.xyz/host/kette.halowerk.com/llms.txt)