State fidelity and purity
Calculate squared Uhlmann fidelity and purity for two supplied single-qubit density matrices. Explicit conventions; no experimental certification.
SearchLiveeip155:8453Exactvia cdp
QuantumScienceResearchBounded-computationEvidence
Calls · 30d
1→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 20 snapshots so far.
$71.48
Verified settled volume
1,272 settlements proven x402 by their on-chain EIP-3009 marker.
$0.019
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 2026-10-12 05:14Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28The 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.
Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.019001USDC≈ $0.019001 USD
on Base · exact scheme
Pay 0.019001 USDC on Base to 0xec84…2de28. The signed payment is good for 1 minute.
- Paid to
- 0xec84…2de28
- USD Coin contract
- 0x8335…02913
- Payment window
- 1 minute
- As published
- 19001 smallest units
19001units
on Arbitrum · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xec84…2de28
- Token contract
- 0xaf88…e5831
- Payment window
- 1 minute
The catalog’s raw entry
[
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"extra": {
"name": "USD Coin",
"version": "2"
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"payTo": "0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28",
"amount": "19001",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
},
{
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
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"payTo": "0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28",
"amount": "19001",
"scheme": "exact",
"network": "eip155:42161",
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}
]Extensions
{
"bazaar": {
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"input": {
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},
"type": "http",
"method": "POST",
"bodyType": "json"
},
"output": {
"type": "json",
"example": {
"result": {
"findings": {
"purity": 1,
"fidelity": 0.5,
"convention": "squared Uhlmann fidelity; Tr(rho*sigma)+2*sqrt(det(rho)*det(sigm…",
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},
"limitations": [
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},
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],
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"amountBaseUnits": "19001"
}
}
},
"schema": {
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"required": [
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"properties": {
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],
"properties": {
"state": {
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"dataClass": {
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],
"type": "string"
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"reference": {
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}
},
"additionalProperties": false
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
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],
"type": "string"
},
"bodyType": {
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"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
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},
"example": {
"type": "object",
"required": [
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"amountBaseUnits",
"inputDigest",
"result",
"boundaries",
"receiptDigest"
],
"properties": {
"result": {
"type": "object"
},
"offerId": {
"enum": [
"quantum-state-fidelity-purity"
],
"type": "string"
},
"version": {
"enum": [
"maha-microproducts/0.1"
],
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},
"boundaries": {
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},
"inputDigest": {
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"receiptDigest": {
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},
"amountBaseUnits": {
"enum": [
"19001"
],
"type": "string"
}
},
"additionalProperties": false
}
}
}
}
}
},
"maha-offer": {
"asset": "USDC",
"amount": "19001",
"method": "POST",
"status": "available",
"network": "eip155:8453",
"offerId": "quantum-state-fidelity-purity",
"networks": [
"eip155:8453",
"eip155:42161"
],
"assetDecimals": 6,
"declarationUrl": "https://www.mahastrategies.com/api/discovery/x402-offers/quantum-state-fidelity-purity",
"maxRequestBytes": 32768,
"canonicalResource": "https://www.mahastrategies.com/api/v1/micro/quantum-state-fidelity-purity",
"declarationInline": "compact",
"payableInProduction": true,
"fullSourceTextStored": false,
"verbatimExcerptsRetained": false
},
"declaration-integrity": {
"metadataVersion": "2026-08-10",
"canonicalResource": "https://www.mahastrategies.com/api/v1/micro/quantum-state-fidelity-purity",
"declarationDigest": "sha256:19e0730e700e805857be1df4b8adb27c3d596626504503c348d365e3ebb7a3eb"
}
}Provenance
- Seen in the source catalog
- 2026-10-12 05:14Z
- Last indexed by Roundhouse
- 2026-10-26 20:20Z
- Last enriched (probe, favicon, geo)
- 2026-10-12 06:16Z
- x402 version
- 2
- Max timeout
- 60s
- Liveness probe
- HTTP 200
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. 20 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 State fidelity and purity 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=State%20fidelity%20and%20purity' 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://www.mahastrategies.com/api/v1/micro/quantum-state-fidelity-purity, 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. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.