HALOWERK kettenwerk
HALOWERK provides paid endpoints that AI agents call and pay for per request via x402 on Base. No account, no API key, no signup.
MediaLiveeip155:8453Exactvia 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.
$11.48
Verified settled volume
2,657 settlements proven x402 by their on-chain EIP-3009 marker.
$0.012
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 18:26Z
—
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": "tx_simulate",
"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": "12000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
],
"pricing": "https://kette.halowerk.com/pricing",
"summary": "Simulates one EVM transaction against a forked chain state and returns exactly what it would do: success or revert reason, gas used, every balance change measured before and after, approvals granted or revoked, the call tree and warnings — without ever signing or broadcasting anything.",
"resource": {
"url": "https://kette.halowerk.com/tx/simulate",
"iconUrl": "https://kette.halowerk.com/favicon.svg",
"mimeType": "application/json",
"description": "Answers the question that stands before every signature: what really happens to my assets and my rights. The call is executed against the state of a named block on a simulation interface, never on the chain — this hub holds no private key and broadcasts nothing. Balance changes are not inferred from events but measured: the same simulation reads every touched balance immediately before and immediately after the call, native currency included, so an outflow that emits no event is still visible. A",
"serviceName": "HALOWERK kettenwerk"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"body": {
"to": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"data": "0x70a08231000000000000000000000000617df6d675425ab4bc3a71e67d1915e026edcc9f",
"from": "0x617DF6d675425ab4bc3A71e67d1915E026EDCC9f",
"chain": "base",
"value": "0"
},
"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",
"from",
"to"
],
"properties": {
"to": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Target address."
},
"gas": {
"type": "integer",
"maximum": 30000000,
"minimum": 21000,
"description": "Optional gas limit for the simulation."
},
"data": {
"type": "string",
"default": "0x",
"pattern": "^0x[0-9a-fA-F]*$",
"description": "Call data."
},
"from": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Sender address. No signature is needed and none is created."
},
"block": {
"type": "string",
"default": "latest",
"description": "\"latest\" or a block number as decimal string."
},
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to simulate on."
},
"value": {
"type": "string",
"default": "0",
"description": "Value in wei, decimal or 0x."
},
"state_overrides": {
"type": "object",
"description": "Optional state overrides per address, in the eth_simulateV1 format (balance, nonce, code, state, stateDiff)."
}
},
"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": "0.012",
"description": "Answers the question that stands before every signature: what really happens to my assets and my rights. The call is executed against the state of a named block on a simulation interface, never on the chain — this hub holds no private key and broadcasts nothing. Balance changes are not inferred from events but measured: the same simulation reads every touched balance immediately before and immediately after the call, native currency included, so an outflow that emits no event is still visible. Approvals granted and revoked are extracted separately and unlimited ones are flagged. Where a public node offers a call tracer, the full internal call tree with depth and the number of storage slots written are included; where it does not, both fields are null and listed in unavailable_fields rather than approximated — currently Arbitrum and BNB Smart Chain have no free tracer. State overrides are supported for what-if questions. A revert is a valid, billable answer with its reason; a simulation that could not be run at all is not billed. The result holds for the stated block only — state can change before execution.",
"inputSchema": {
"type": "object",
"required": [
"chain",
"from",
"to"
],
"properties": {
"to": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Target address."
},
"gas": {
"type": "integer",
"maximum": 30000000,
"minimum": 21000,
"description": "Optional gas limit for the simulation."
},
"data": {
"type": "string",
"default": "0x",
"pattern": "^0x[0-9a-fA-F]*$",
"description": "Call data."
},
"from": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Sender address. No signature is needed and none is created."
},
"block": {
"type": "string",
"default": "latest",
"description": "\"latest\" or a block number as decimal string."
},
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to simulate on."
},
"value": {
"type": "string",
"default": "0",
"description": "Value in wei, decimal or 0x."
},
"state_overrides": {
"type": "object",
"description": "Optional state overrides per address, in the eth_simulateV1 format (balance, nonce, code, state, stateDiff)."
}
},
"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.
0.012USDC≈ $0.012 USD
on Base · exact scheme
Pay 0.012 USDC on Base to 0x2880…C4E5E. The signed payment is good for 5 minutes.
- Paid to
- 0x2880…C4E5E
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 12000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"asset": "USDC",
"version": "2",
"eip712Domain": {
"name": "USD Coin",
"chainId": 8453,
"version": "2",
"verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"network_name": "Base Mainnet",
"assetTransferMethod": "eip3009"
},
"payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"amount": "12000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"to": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"from": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"chain": "ethereum"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}
},
"schema": {
"type": "object",
"$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",
"from",
"to"
],
"properties": {
"to": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Target address."
},
"gas": {
"type": "integer",
"maximum": 30000000,
"minimum": 21000,
"description": "Optional gas limit for the simulation."
},
"data": {
"type": "string",
"default": "0x",
"pattern": "^0x[0-9a-fA-F]*$",
"description": "Call data."
},
"from": {
"type": "string",
"pattern": "^0x[0-9a-fA-F]{40}$",
"description": "Sender address. No signature is needed and none is created."
},
"block": {
"type": "string",
"default": "latest",
"description": "\"latest\" or a block number as decimal string."
},
"chain": {
"enum": [
"ethereum",
"base",
"arbitrum",
"optimism",
"polygon",
"bsc"
],
"type": "string",
"description": "Chain to simulate on."
},
"value": {
"type": "string",
"default": "0",
"description": "Value in wei, decimal or 0x."
},
"state_overrides": {
"type": "object",
"description": "Optional state overrides per address, in the eth_simulateV1 format (balance, nonce, code, state, stateDiff)."
}
},
"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 18:26Z
- Last indexed by Roundhouse
- 2026-09-08 18:00Z
- Last enriched (probe, favicon, geo)
- 2026-09-20 18:45Z
- 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/tx/simulate, 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.