HALOWERK kettenwerk
Reads the fee history of the last 20 blocks on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain and returns what a transaction costs right now. Priority fees come from the 10th, 50th and 90th percentile of the tips actually paid in those blocks — the percentile used is named, not hidden. On rollups the L1 data fee is quoted separately from the L2 execution fee, because it is often the larger part and an estimate that merges them is simply wrong; the L1 part is computed from the cha
DataLiveeip155:8453Exactvia cdp
Calls · 30d
1→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 16 snapshots so far.
$11.47
Verified settled volume
2,654 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0020
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-08-09 10:32Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5EThe wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"docs": "https://kette.halowerk.com/llms.txt",
"name": "gas_estimate",
"error": "payment_required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"asset": "USDC",
"version": "2",
"eip712Domain": {
"name": "USD Coin",
"chainId": 8453,
"version": "2",
"verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"network_name": "Base Mainnet",
"assetTransferMethod": "eip3009"
},
"payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"amount": "2000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
],
"pricing": "https://kette.halowerk.com/pricing",
"summary": "Current gas cost on one EVM chain: base fee, priority fee for slow, normal and fast, the suggested max fee, the expected wait in seconds measured from real block times, and the total cost in USD for a typical transaction.",
"resource": {
"url": "https://kette.halowerk.com/gas",
"iconUrl": "https://kette.halowerk.com/favicon.svg",
"mimeType": "application/json",
"description": "Reads the fee history of the last 20 blocks on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain and returns what a transaction costs right now. Priority fees come from the 10th, 50th and 90th percentile of the tips actually paid in those blocks — the percentile used is named, not hidden. On rollups the L1 data fee is quoted separately from the L2 execution fee, because it is often the larger part and an estimate that merges them is simply wrong; the L1 part is computed from the cha",
"serviceName": "HALOWERK kettenwerk"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"body": {
"chain": "ethereum"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"required": [
"chain"
],
"properties": {
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to read fees from."
},
"speed": {
"enum": [
"langsam",
"normal",
"schnell",
"alle"
],
"type": "string",
"default": "alle",
"description": "Which speed level to highlight. All three are always returned."
},
"tx_type": {
"enum": [
"native_transfer",
"erc20_transfer",
"erc20_approve",
"swap",
"nft_mint",
"contract_deploy"
],
"type": "string",
"default": "erc20_transfer",
"description": "Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer."
}
},
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
}
}
}
}
},
"price_usdc": "0.002",
"description": "Reads the fee history of the last 20 blocks on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain and returns what a transaction costs right now. Priority fees come from the 10th, 50th and 90th percentile of the tips actually paid in those blocks — the percentile used is named, not hidden. On rollups the L1 data fee is quoted separately from the L2 execution fee, because it is often the larger part and an estimate that merges them is simply wrong; the L1 part is computed from the chain's own gas price oracle for a synthetic payload of a stated byte size. Waiting times are derived from the measured average block time over the last blocks, not guessed, and the number of blocks assumed per speed level is disclosed. USD cost needs a price for the native currency from two independent sources; if neither answers, the USD fields stay null instead of being estimated. Arbitrum has no OP-Stack gas price oracle, so its L1 data fee is reported as unavailable rather than approximated. This is a measurement, not a recommendation.",
"inputSchema": {
"type": "object",
"required": [
"chain"
],
"properties": {
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to read fees from."
},
"speed": {
"enum": [
"langsam",
"normal",
"schnell",
"alle"
],
"type": "string",
"default": "alle",
"description": "Which speed level to highlight. All three are always returned."
},
"tx_type": {
"enum": [
"native_transfer",
"erc20_transfer",
"erc20_approve",
"swap",
"nft_mint",
"contract_deploy"
],
"type": "string",
"default": "erc20_transfer",
"description": "Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer."
}
},
"additionalProperties": false
},
"price_model": "per_call",
"x402Version": 2,
"instructions": "Sign the accepted terms with an x402 client and repeat the request with the payment header.",
"outputSchema": {
"type": "object"
},
"payment_header": "PAYMENT-SIGNATURE",
"capability_request": {
"url": "https://bedarf.halowerk.com/capabilities/request",
"cost": "free",
"method": "POST",
"description": "Missing a capability, or does the scope not fit? Report the need here - no payment required. Similar reports are bundled; the response returns an id you can check back on.",
"body_example": {
"max_price": 0.01,
"description": "what exactly is needed",
"requested_capability": "short label"
}
}
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.002USDC≈ $0.002 USD
on Base · exact scheme
Pay 0.002 USDC on Base to 0x2880…C4E5E. The signed payment is good for 5 minutes.
- Paid to
- 0x2880…C4E5E
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 2000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"asset": "USDC",
"version": "2",
"eip712Domain": {
"name": "USD Coin",
"chainId": 8453,
"version": "2",
"verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"network_name": "Base Mainnet",
"assetTransferMethod": "eip3009"
},
"payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"amount": "2000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"chain": "ethereum"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"required": [
"chain"
],
"properties": {
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to read fees from."
},
"speed": {
"enum": [
"langsam",
"normal",
"schnell",
"alle"
],
"type": "string",
"default": "alle",
"description": "Which speed level to highlight. All three are always returned."
},
"tx_type": {
"enum": [
"native_transfer",
"erc20_transfer",
"erc20_approve",
"swap",
"nft_mint",
"contract_deploy"
],
"type": "string",
"default": "erc20_transfer",
"description": "Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer."
}
},
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-08-09 10:32Z
- Last indexed by Roundhouse
- 2026-09-08 10:30Z
- Last enriched (probe, favicon, geo)
- 2026-09-20 19:15Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 402
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 16 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service HALOWERK kettenwerk and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=HALOWERK%20kettenwerk' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://kette.halowerk.com/gas, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402, or use an organization key from https://roundhouseai.io/dashboard/team. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.