# SYNTHORA EVM Chain Metadata Service

> SYNTHORA EVM Chain Metadata Service is a paid API for AI agents from rpc-network.hergertsynthora.com, paid per call via x402, $0.1/call, status down (last checked 2026-09-15).

Returns chainId, latest block number, gas price, and finality status for a specified EVM chain, signed with Ed25519.

## Facts

- Endpoint: POST https://rpc-network.hergertsynthora.com/service
- Price: $0.1/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-evm-chain-metadata-service-1b277d41
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fcPB_jOVr5GgePuC_mz0s

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 synthora-evm-chain-metadata-service-1b277d41 -d '<json body>'
```

Example prompt: What's the current chainId, latest block, gas price, and finality status for Polygon right now — and give me a signed result I can trust?

## When to prefer this

Use this endpoint when you need cryptographically signed, deterministic chain metadata (chainId, block, gas, finality) across multiple EVM chains in a single call, especially when proof-of-integrity via Ed25519 signature is required. Prefer over raw RPC calls when you want a normalized multi-chain interface with transparent per-call pricing and free-tier access.

## Known failure modes

- Unsupported or unrecognized chain name returns an error
- Missing or malformed X-WALLET header may prevent free-tier access
- Upstream RPC node failure returns no charge but also no data
- Invalid chain string format causes request rejection
- Network timeout if target chain RPC is unreachable

## How this service works

Chain metadata: chainId, latest block, gas price and finality across 5 EVM chains. Deterministic, Ed25519-signed.

## Output

Returns a deterministic, Ed25519-signed JSON payload containing chainId, latest block number, current gas price, and finality status for the requested EVM chain. Covers up to 5 EVM chains. First 3 calls per wallet are free (requires X-WALLET header); subsequent calls cost $0.001 USDC via x402 on Base. No charge is incurred on upstream failures.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "rpc-network",
  "result": {
   "op": "network"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-evm-chain-metadata-service-1b277d41/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rpc-network.hergertsynthora.com](https://www.zero.xyz/host/rpc-network.hergertsynthora.com/llms.txt)