# markt.halowerk.com Ethereum Gas Price Estimator

> markt.halowerk.com Ethereum Gas Price Estimator is a paid API for AI agents from markt.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns current Ethereum gas fee estimates including base fee, recommended bid in gwei, and USD cost, using eth_feeHistory over the last 10 blocks with 25/50/75 percentile rewards.

## Facts

- Endpoint: POST https://markt.halowerk.com/gas
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/markt-halowerk-com-ethereum-gas-price-estimator-f58b2e57
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_J6N-guvLiPW3_i5rdR6lu

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 markt-halowerk-com-ethereum-gas-price-estimator-f58b2e57 -d '<json body>'
```

Example prompt: What's the recommended gas fee in gwei for sending an Ethereum transaction right now, and what would that cost me in USD?

## When to prefer this

Choose this endpoint when you need a ready-to-use recommended gas bid for Ethereum transactions, including USD cost conversion, rather than raw node data. It abstracts away EIP-1559 complexity (base fee + priority fee logic) and handles node fallback automatically. Prefer over raw RPC calls when you need a single actionable number rather than raw fee history arrays.

## Known failure modes

- Node does not support eth_feeHistory — falls back to eth_gasPrice automatically
- RPC node unreachable or rate-limited — returns error
- Stale block data if node is behind — may produce outdated estimates
- USD conversion may lag if price feed is delayed

## How this service works

Reads eth_feeHistory over the last ten blocks with reward percentiles 25, 50 and 75, and falls back to eth_gasPrice when a node does not serve fee history. base_fee_gwei is the base fee of the next block, not of the last one, because that is the fee a transaction sent now will actually pay. recommended_gwei is a bid, not an observation: priority at the median plus a base fee doubled to survive several full blocks, and the rule is stated in recommended_rule. cost_usd converts that into dollars fo

## Output

Returns base_fee_gwei (the base fee of the next block, not the last), recommended_gwei (a computed bid based on median priority fee plus doubled base fee for block survival), recommended_rule (the formula used), and cost_usd (the recommended bid converted to US dollars). Falls back to eth_gasPrice if the node does not support fee history.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "ethereum",
    "base"
   ],
   "type": "string",
   "default": "ethereum",
   "description": "Chain to measure. ethereum or base."
  },
  "action": {
   "enum": [
    "transfer",
    "erc20",
    "swap"
   ],
   "type": "string",
   "default": "transfer",
   "description": "Which transaction the cost estimate is for: transfer, erc20 or swap."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/markt-halowerk-com-ethereum-gas-price-estimator-f58b2e57/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from markt.halowerk.com](https://www.zero.xyz/host/markt.halowerk.com/llms.txt)