ToolVet
75trust / 100

Context Context Delta

by nova-retail-controlled-proof.onrender.com in Other

x402 APIPassing, checked 2 h ago

Nova retail context_delta context resource

POST
https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta
Price
$0.02
per call in USDC
Uptime
100%
last 30 days
Response time
321 ms
898 ms slowest 5%
Last check
Passed
2 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta

Each call costs $0.02 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta
content-type: application/json

{
  "current_context": {
    "authority_effect": "none",
    "confidence": {
      "basis": "Example client-carried observation for public contract discovery.",
      "level": "medium"
    },
    "context_status": "partially_resolved",
    "contradictions": [],
    "evidence": [
      {
        "claim_or_observation": "last_price=100100 BTC-USD",
        "evidence_id": "public-example-last-price",
        "evidence_status": "observed",
        "source_id": "public-example-source"
      }
    ],
    "freshness": {
      "freshness_status": "fresh",
      "observed_at": "2026-09-12T12:00:00Z",
      "source_age_seconds": 0
    },
    "generated_at": "2026-09-12T12:00:00Z",
    "limitations": [
      {
        "description": "Discovery example only; evidence remains client-carried and unverified.",
        "impact": "limited_scope",
        "limitation_id": "public-example-scope"
      }
    ],
    "provenance": [
      {
        "claim_reconciliation_status": "not_assessed",
        "contribution_scope": [
          "market_pair_last_price"
        ],
        "observed_at": "2026-09-12T12:00:00Z",
        "source_id": "public-example-source",
        "source_status": "present_unverified",
        "source_type": "public_example"
      }
    ],
    "resource_id": "state-ping-example-current",
    "resource_type": "state_ping",
    "schema_version": "0.1.0",
    "subject": {
      "label": "BTC/USD",
      "subject_id": "BTC-USD",
      "subject_type": "market_pair"
    },
    "unresolved_evidence": []
  },
  "generated_at": "2026-09-12T12:00:00Z",
  "previous_context": {
    "authority_effect": "none",
    "confidence": {
      "basis": "Example client-carried observation for public contract discovery.",
      "level": "medium"
    },
    "context_status": "partially_resolved",
    "contradictions": [],
    "evidence": [
      {
        "claim_or_observation": "last_price=100000 BTC-USD",
        "evidence_id": "public-example-last-price",
        "evidence_status": "observed",
        "source_id": "public-example-source"
      }
    ],
    "freshness": {
      "freshness_status": "fresh",
      "observed_at": "2026-09-12T11:55:00Z",
      "source_age_seconds": 0
    },
    "generated_at": "2026-09-12T11:55:00Z",
    "limitations": [
      {
        "description": "Discovery example only; evidence remains client-carried and unverified.",
        "impact": "limited_scope",
        "limitation_id": "public-example-scope"
      }
    ],
    "provenance": [
      {
        "claim_reconciliation_status": "not_assessed",
        "contribution_scope": [
          "market_pair_last_price"
        ],
        "observed_at": "2026-09-12T11:55:00Z",
        "source_id": "public-example-source",
        "source_status": "present_unverified",
        "source_type": "public_example"
      }
    ],
    "resource_id": "state-ping-example-previous",
    "resource_type": "state_ping",
    "schema_version": "0.1.0",
    "subject": {
      "label": "BTC/USD",
      "subject_id": "BTC-USD",
      "subject_type": "market_pair"
    },
    "unresolved_evidence": []
  }
}

Parameters

ParameterTypeRequiredDescription
current_contextretailContextYes
generated_atstring (date-time)Yes
previous_contextretailContextYes

Example response

The provider's example. We can't check it without paying.

Example response, 77 lines
{
  "authority_effect": "none",
  "confidence_changes": [],
  "contradiction_changes": [],
  "current_context_id": "state-ping-example-current",
  "delta_status": "changed",
  "evidence_state_changes": [
    {
      "change_id": "evidence-change-d18b1a54a0b68c6855212169",
      "change_type": "content_changed",
      "current_status": "observed",
      "evidence_id": "public-example-last-price",
      "previous_status": "observed",
      "source_id": "public-example-source"
    }
  ],
  "freshness_changes": [
    {
      "change_id": "freshness-change-ebecda1fcbfb3c08e114de17",
      "current_value": "2026-09-12T12:00:00Z",
      "field": "observed_at",
      "previous_value": "2026-09-12T11:55:00Z"
    }
  ],
  "generated_at": "2026-09-12T12:00:00Z",
  "limitation_changes": [],
  "limitations": [],
  "material_changes": [
    {
      "category": "freshness",
      "change_id": "material-change-aad59f135d32b8e6cfb9f8e3",
      "change_type": "value_changed",
      "current_value": "2026-09-12T12:00:00Z",
      "field": "observed_at",
      "item_id": null,
      "previous_value": "2026-09-12T11:55:00Z"
    },
    {
      "category": "provenance",
      "change_id": "material-change-ee1ca54c09fa66775144e3a4",
      "change_type": "value_changed",
      "current_value": "2026-09-12T12:00:00Z",
      "field": "observed_at",
      "item_id": "public-example-source",
      "previous_value": "2026-09-12T11:55:00Z"
    },
    {
      "category": "evidence",
      "change_id": "material-change-f712bc18f08980ebc25df088",
      "change_type": "content_changed",
      "current_value": "{\"claim_or_observation\":\"last_price=100100 BTC-USD\",\"evidence_id\":\"public-example-last-price\",\"source_id\":\"public-example-source\"}",
      "field": "content",
      "item_id": "public-example-last-price",
      "previous_value": "{\"claim_or_observation\":\"last_price=100000 BTC-USD\",\"evidence_id\":\"public-example-last-price\",\"source_id\":\"public-example-source\"}"
    }
  ],
  "previous_context_id": "state-ping-example-previous",
  "provenance_changes": [
    {
      "change_id": "provenance-change-c14455d3e5b633ef90196215",
      "change_type": "observed_at_changed",
      "current_value": "2026-09-12T12:00:00Z",
      "field": "observed_at",
      "previous_value": "2026-09-12T11:55:00Z",
      "source_id": "public-example-source"
    }
  ],
  "resource_id": "context-delta-91e9a7267ab3fcdce8fe8f66",
  "resource_type": "context_delta",
  "schema_version": "0.1.0",
  "subject": {
    "label": "BTC/USD",
    "subject_id": "BTC-USD",
    "subject_type": "market_pair"
  },
  "unresolved_evidence_changes": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.02.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta' \
  -H 'content-type: application/json' \
  --data-raw '{"current_context":{"authority_effect":"none","confidence":{"basis":"Example client-carried observation for public contract discovery.","level":"medium"},"context_status":"partially_resolved","contradictions":[],"evidence":[{"claim_or_observation":"last_price=100100 BTC-USD","evidence_id":"public-example-last-price","evidence_status":"observed","source_id":"public-example-source"}],"freshness":{"freshness_status":"fresh","observed_at":"2026-09-12T12:00:00Z","source_age_seconds":0},"generated_at":"2026-09-12T12:00:00Z","limitations":[{"description":"Discovery example only; evidence remains client-carried and unverified.","impact":"limited_scope","limitation_id":"public-example-scope"}],"provenance":[{"claim_reconciliation_status":"not_assessed","contribution_scope":["market_pair_last_price"],"observed_at":"2026-09-12T12:00:00Z","source_id":"public-example-source","source_status":"present_unverified","source_type":"public_example"}],"resource_id":"state-ping-example-current","resource_type":"state_ping","schema_version":"0.1.0","subject":{"label":"BTC/USD","subject_id":"BTC-USD","subject_type":"market_pair"},"unresolved_evidence":[]},"generated_at":"2026-09-12T12:00:00Z","previous_context":{"authority_effect":"none","confidence":{"basis":"Example client-carried observation for public contract discovery.","level":"medium"},"context_status":"partially_resolved","contradictions":[],"evidence":[{"claim_or_observation":"last_price=100000 BTC-USD","evidence_id":"public-example-last-price","evidence_status":"observed","source_id":"public-example-source"}],"freshness":{"freshness_status":"fresh","observed_at":"2026-09-12T11:55:00Z","source_age_seconds":0},"generated_at":"2026-09-12T11:55:00Z","limitations":[{"description":"Discovery example only; evidence remains client-carried and unverified.","impact":"limited_scope","limitation_id":"public-example-scope"}],"provenance":[{"claim_reconciliation_status":"not_assessed","contribution_scope":["market_pair_last_price"],"observed_at":"2026-09-12T11:55:00Z","source_id":"public-example-source","source_status":"present_unverified","source_type":"public_example"}],"resource_id":"state-ping-example-previous","resource_type":"state_ping","schema_version":"0.1.0","subject":{"label":"BTC/USD","subject_id":"BTC-USD","subject_type":"market_pair"},"unresolved_evidence":[]}}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta' \
  -H 'content-type: application/json' \
  --data-raw '{"current_context":{"authority_effect":"none","confidence":{"basis":"Example client-carried observation for public contract discovery.","level":"medium"},"context_status":"partially_resolved","contradictions":[],"evidence":[{"claim_or_observation":"last_price=100100 BTC-USD","evidence_id":"public-example-last-price","evidence_status":"observed","source_id":"public-example-source"}],"freshness":{"freshness_status":"fresh","observed_at":"2026-09-12T12:00:00Z","source_age_seconds":0},"generated_at":"2026-09-12T12:00:00Z","limitations":[{"description":"Discovery example only; evidence remains client-carried and unverified.","impact":"limited_scope","limitation_id":"public-example-scope"}],"provenance":[{"claim_reconciliation_status":"not_assessed","contribution_scope":["market_pair_last_price"],"observed_at":"2026-09-12T12:00:00Z","source_id":"public-example-source","source_status":"present_unverified","source_type":"public_example"}],"resource_id":"state-ping-example-current","resource_type":"state_ping","schema_version":"0.1.0","subject":{"label":"BTC/USD","subject_id":"BTC-USD","subject_type":"market_pair"},"unresolved_evidence":[]},"generated_at":"2026-09-12T12:00:00Z","previous_context":{"authority_effect":"none","confidence":{"basis":"Example client-carried observation for public contract discovery.","level":"medium"},"context_status":"partially_resolved","contradictions":[],"evidence":[{"claim_or_observation":"last_price=100000 BTC-USD","evidence_id":"public-example-last-price","evidence_status":"observed","source_id":"public-example-source"}],"freshness":{"freshness_status":"fresh","observed_at":"2026-09-12T11:55:00Z","source_age_seconds":0},"generated_at":"2026-09-12T11:55:00Z","limitations":[{"description":"Discovery example only; evidence remains client-carried and unverified.","impact":"limited_scope","limitation_id":"public-example-scope"}],"provenance":[{"claim_reconciliation_status":"not_assessed","contribution_scope":["market_pair_last_price"],"observed_at":"2026-09-12T11:55:00Z","source_id":"public-example-source","source_status":"present_unverified","source_type":"public_example"}],"resource_id":"state-ping-example-previous","resource_type":"state_ping","schema_version":"0.1.0","subject":{"label":"BTC/USD","subject_id":"BTC-USD","subject_type":"market_pair"},"unresolved_evidence":[]}}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fnova-retail-controlled-proof.onrender.com%2Fretail%2Fv1%2Fcontext%2Fcontext-delta&method=POST
const res = await pay("https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "current_context": {
      "authority_effect": "none",
      "confidence": {
        "basis": "Example client-carried observation for public contract discovery.",
        "level": "medium"
      },
      "context_status": "partially_resolved",
      "contradictions": [],
      "evidence": [
        {
          "claim_or_observation": "last_price=100100 BTC-USD",
          "evidence_id": "public-example-last-price",
          "evidence_status": "observed",
          "source_id": "public-example-source"
        }
      ],
      "freshness": {
        "freshness_status": "fresh",
        "observed_at": "2026-09-12T12:00:00Z",
        "source_age_seconds": 0
      },
      "generated_at": "2026-09-12T12:00:00Z",
      "limitations": [
        {
          "description": "Discovery example only; evidence remains client-carried and unverified.",
          "impact": "limited_scope",
          "limitation_id": "public-example-scope"
        }
      ],
      "provenance": [
        {
          "claim_reconciliation_status": "not_assessed",
          "contribution_scope": [
            "market_pair_last_price"
          ],
          "observed_at": "2026-09-12T12:00:00Z",
          "source_id": "public-example-source",
          "source_status": "present_unverified",
          "source_type": "public_example"
        }
      ],
      "resource_id": "state-ping-example-current",
      "resource_type": "state_ping",
      "schema_version": "0.1.0",
      "subject": {
        "label": "BTC/USD",
        "subject_id": "BTC-USD",
        "subject_type": "market_pair"
      },
      "unresolved_evidence": []
    },
    "generated_at": "2026-09-12T12:00:00Z",
    "previous_context": {
      "authority_effect": "none",
      "confidence": {
        "basis": "Example client-carried observation for public contract discovery.",
        "level": "medium"
      },
      "context_status": "partially_resolved",
      "contradictions": [],
      "evidence": [
        {
          "claim_or_observation": "last_price=100000 BTC-USD",
          "evidence_id": "public-example-last-price",
          "evidence_status": "observed",
          "source_id": "public-example-source"
        }
      ],
      "freshness": {
        "freshness_status": "fresh",
        "observed_at": "2026-09-12T11:55:00Z",
        "source_age_seconds": 0
      },
      "generated_at": "2026-09-12T11:55:00Z",
      "limitations": [
        {
          "description": "Discovery example only; evidence remains client-carried and unverified.",
          "impact": "limited_scope",
          "limitation_id": "public-example-scope"
        }
      ],
      "provenance": [
        {
          "claim_reconciliation_status": "not_assessed",
          "contribution_scope": [
            "market_pair_last_price"
          ],
          "observed_at": "2026-09-12T11:55:00Z",
          "source_id": "public-example-source",
          "source_status": "present_unverified",
          "source_type": "public_example"
        }
      ],
      "resource_id": "state-ping-example-previous",
      "resource_type": "state_ping",
      "schema_version": "0.1.0",
      "subject": {
        "label": "BTC/USD",
        "subject_id": "BTC-USD",
        "subject_type": "market_pair"
      },
      "unresolved_evidence": []
    }
  }),
});
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://nova-retail-controlled-proof.onrender.com/retail/v1/context/context-delta",
        json={
            "current_context": {
                "authority_effect": "none",
                "confidence": {
                    "basis": "Example client-carried observation for public contract discovery.",
                    "level": "medium",
                },
                "context_status": "partially_resolved",
                "contradictions": [],
                "evidence": [
                    {
                        "claim_or_observation": "last_price=100100 BTC-USD",
                        "evidence_id": "public-example-last-price",
                        "evidence_status": "observed",
                        "source_id": "public-example-source",
                    },
                ],
                "freshness": {
                    "freshness_status": "fresh",
                    "observed_at": "2026-09-12T12:00:00Z",
                    "source_age_seconds": 0,
                },
                "generated_at": "2026-09-12T12:00:00Z",
                "limitations": [
                    {
                        "description": "Discovery example only; evidence remains client-carried and unverified.",
                        "impact": "limited_scope",
                        "limitation_id": "public-example-scope",
                    },
                ],
                "provenance": [
                    {
                        "claim_reconciliation_status": "not_assessed",
                        "contribution_scope": [
                            "market_pair_last_price",
                        ],
                        "observed_at": "2026-09-12T12:00:00Z",
                        "source_id": "public-example-source",
                        "source_status": "present_unverified",
                        "source_type": "public_example",
                    },
                ],
                "resource_id": "state-ping-example-current",
                "resource_type": "state_ping",
                "schema_version": "0.1.0",
                "subject": {
                    "label": "BTC/USD",
                    "subject_id": "BTC-USD",
                    "subject_type": "market_pair",
                },
                "unresolved_evidence": [],
            },
            "generated_at": "2026-09-12T12:00:00Z",
            "previous_context": {
                "authority_effect": "none",
                "confidence": {
                    "basis": "Example client-carried observation for public contract discovery.",
                    "level": "medium",
                },
                "context_status": "partially_resolved",
                "contradictions": [],
                "evidence": [
                    {
                        "claim_or_observation": "last_price=100000 BTC-USD",
                        "evidence_id": "public-example-last-price",
                        "evidence_status": "observed",
                        "source_id": "public-example-source",
                    },
                ],
                "freshness": {
                    "freshness_status": "fresh",
                    "observed_at": "2026-09-12T11:55:00Z",
                    "source_age_seconds": 0,
                },
                "generated_at": "2026-09-12T11:55:00Z",
                "limitations": [
                    {
                        "description": "Discovery example only; evidence remains client-carried and unverified.",
                        "impact": "limited_scope",
                        "limitation_id": "public-example-scope",
                    },
                ],
                "provenance": [
                    {
                        "claim_reconciliation_status": "not_assessed",
                        "contribution_scope": [
                            "market_pair_last_price",
                        ],
                        "observed_at": "2026-09-12T11:55:00Z",
                        "source_id": "public-example-source",
                        "source_status": "present_unverified",
                        "source_type": "public_example",
                    },
                ],
                "resource_id": "state-ping-example-previous",
                "resource_type": "state_ping",
                "schema_version": "0.1.0",
                "subject": {
                    "label": "BTC/USD",
                    "subject_id": "BTC-USD",
                    "subject_type": "market_pair",
                },
                "unresolved_evidence": [],
            },
        },
    )
    print(res.status_code, res.text)

Security scan

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Recent checks

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2 days agoPassed402814 ms$0.02