HALOWERK marktwerk
Compares the open interest recorded now with the value this hub recorded itself at the start of the window, so both numbers come from the same source and the same basis. Notional value is always taken with the price of its own point in time, never recomputed with the current price. price_change_pct and volume_change_pct cover exactly the same window from the recorded minute candles. interpretation follows a rule printed in the answer, so a buyer can recompute it: price and open interest rising t
SearchLiveeip155:8453Exactvia 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
2,656 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0030
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 18:18Z
—
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://markt.halowerk.com/llms.txt",
"name": "open_interest_change",
"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": "3000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
],
"pricing": "https://markt.halowerk.com/pricing",
"summary": "Change in open interest over one, four or twenty four hours against this hub own recorded history, together with the price and volume change over the same window and a stated interpretation with its rule.",
"resource": {
"url": "https://markt.halowerk.com/open-interest",
"iconUrl": "https://markt.halowerk.com/favicon.svg",
"mimeType": "application/json",
"description": "Compares the open interest recorded now with the value this hub recorded itself at the start of the window, so both numbers come from the same source and the same basis. Notional value is always taken with the price of its own point in time, never recomputed with the current price. price_change_pct and volume_change_pct cover exactly the same window from the recorded minute candles. interpretation follows a rule printed in the answer, so a buyer can recompute it: price and open interest rising t",
"serviceName": "HALOWERK marktwerk"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"body": {
"symbol": "BTC/USDT"
},
"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": [
"symbol"
],
"properties": {
"symbol": {
"type": "string",
"pattern": "^[A-Za-z0-9]{2,15}/[A-Za-z0-9]{2,15}$",
"description": "Perpetual as BASE/QUOTE, for example BTC/USDT."
},
"venues": {
"type": "array",
"items": {
"enum": [
"binance-futures"
],
"type": "string"
},
"maxItems": 1,
"minItems": 1,
"description": "Venues whose open interest this hub records. Only Binance USDⓈ-M Futures is recorded so far.",
"uniqueItems": true
},
"window": {
"enum": [
"1h",
"4h",
"24h"
],
"type": "string",
"default": "1h",
"description": "Comparison window."
}
},
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
}
}
}
}
},
"price_usdc": "0.003",
"description": "Compares the open interest recorded now with the value this hub recorded itself at the start of the window, so both numbers come from the same source and the same basis. Notional value is always taken with the price of its own point in time, never recomputed with the current price. price_change_pct and volume_change_pct cover exactly the same window from the recorded minute candles. interpretation follows a rule printed in the answer, so a buyer can recompute it: price and open interest rising together is a build up, price rising while open interest falls is an unwind, and a move below the noise threshold stays unklar instead of being forced into a label. Without a recorded comparison point the call answers with charged=false and names the date from which the window will be covered.",
"inputSchema": {
"type": "object",
"required": [
"symbol"
],
"properties": {
"symbol": {
"type": "string",
"pattern": "^[A-Za-z0-9]{2,15}/[A-Za-z0-9]{2,15}$",
"description": "Perpetual as BASE/QUOTE, for example BTC/USDT."
},
"venues": {
"type": "array",
"items": {
"enum": [
"binance-futures"
],
"type": "string"
},
"maxItems": 1,
"minItems": 1,
"description": "Venues whose open interest this hub records. Only Binance USDⓈ-M Futures is recorded so far.",
"uniqueItems": true
},
"window": {
"enum": [
"1h",
"4h",
"24h"
],
"type": "string",
"default": "1h",
"description": "Comparison window."
}
},
"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",
"properties": {
"venue": {
"type": "string"
},
"age_ms": {
"type": "integer"
},
"oi_now": {
"type": [
"number",
"null"
]
},
"symbol": {
"type": "string"
},
"ts_now": {
"type": "integer"
},
"window": {
"type": "string"
},
"hinweis": {
"type": "string"
},
"oi_then": {
"type": [
"number",
"null"
]
},
"ts_then": {
"type": "integer"
},
"evidence": {
"type": "object"
},
"change_abs": {
"type": [
"number",
"null"
]
},
"change_pct": {
"type": [
"number",
"null"
]
},
"interpretation": {
"type": "string"
},
"oi_notional_usd": {
"type": "object"
},
"thresholds_used": {
"type": "object"
},
"price_change_pct": {
"type": [
"number",
"null"
]
},
"volume_change_pct": {
"type": [
"number",
"null"
]
},
"unavailable_fields": {
"type": "array",
"items": {
"type": "string"
}
},
"interpretation_rule": {
"type": "string"
}
}
},
"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.
0.003USDC≈ $0.003 USD
on Base · exact scheme
Pay 0.003 USDC on Base to 0x2880…C4E5E. The signed payment is good for 5 minutes.
- Paid to
- 0x2880…C4E5E
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 3000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"asset": "USDC",
"version": "2",
"eip712Domain": {
"name": "USD Coin",
"chainId": 8453,
"version": "2",
"verifyingContract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"network_name": "Base Mainnet",
"assetTransferMethod": "eip3009"
},
"payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"amount": "3000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"symbol": "BTC/USDT"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}
},
"schema": {
"type": "object",
"$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": [
"symbol"
],
"properties": {
"symbol": {
"type": "string",
"pattern": "^[A-Za-z0-9]{2,15}/[A-Za-z0-9]{2,15}$",
"description": "Perpetual as BASE/QUOTE, for example BTC/USDT."
},
"venues": {
"type": "array",
"items": {
"enum": [
"binance-futures"
],
"type": "string"
},
"maxItems": 1,
"minItems": 1,
"description": "Venues whose open interest this hub records. Only Binance USDⓈ-M Futures is recorded so far.",
"uniqueItems": true
},
"window": {
"enum": [
"1h",
"4h",
"24h"
],
"type": "string",
"default": "1h",
"description": "Comparison window."
}
},
"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 18:18Z
- Last indexed by Roundhouse
- 2026-09-08 18:00Z
- 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 marktwerk 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%20marktwerk' 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://markt.halowerk.com/open-interest, 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.