Publish a deterministic claim about a Base proxy and let the market try to break it
Publish a deterministic claim about a Base proxy and let the market try to break it. You assert that a contract's implementation slot held one address across a block range, fund a reward for whoever finds a block where it did not, and Tereno writes the claim onchain and adjudicates counterexamples by historical storage reads. If nobody collects before your deadline, you get a reproducible survival receipt: not an audit, but proof the claim stood in public with money on it.
250000 (raw units)
price
2
calls / 30d
1
unique payers
2026-09-13
updated
Provider
www.tereno.xyz · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0xfbF218ACCBb0D57fc4E8fc3E2A885C910c4C9e94",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "250000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"method": "POST",
"queryParams": {
"address": "0x1111111111111111111111111111111111111111",
"claimType": "contract.upgrade.window.claim",
"deadlineHours": 72,
"fromBlock": 20000000,
"rewardUsd": 5,
"toBlock": 20500000,
"wallet": "0x2222222222222222222222222222222222222222"
},
"type": "http"
},
"output": {
"example": {
"breadcrumbStatus": "written",
"claim": {
"claimId": "0xabc",
"claimType": "contract.upgrade.window.claim",
"status": "open"
},
"pricing": {
"currency": "USDC",
"pricePaidUsd": 0.25
},
"receiptUrl": "/api/v1/claims/0xabc/receipt"
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"POST"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"properties": {
"address": {
"description": "Base proxy contract the assertion is about.",
"pattern": "^0x[a-fA-F0-9]{40}$",
"type": "string"
},
"claimType": {
"const": "contract.upgrade.window.claim",
"description": "The only claim type whose survival is worth a receipt."
},
"deadlineHours": {
"description": "How long the claim stays open to challenge, 1 to 720.",
"type": "integer"
},
"fromBlock": {
"description": "Inclusive start of the window. The window must span 1000 to 2000000 blocks.",
"type": "integer"
},
"implementation": {
"description": "Optional. Defaults to whatever the implementation slot resolves to at toBlock.",
"type": [
"string",
"null"
]
},
"rewardUsd": {
"description": "What you will pay the first wallet that falsifies your claim. Not escrowed by Tereno.",
"type": "number"
},
"toBlock": {
"description": "Inclusive end of the window. Must not be in the future.",
"type": "integer"
},
"wallet": {
"description": "The opener wallet, which must sign the request.",
"pattern": "^0x[a-fA-F0-9]{40}$",
"type": "string"
}
},
"required": [
"address",
"fromBlock",
"toBlock",
"rewardUsd",
"deadlineHours",
"wallet"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"breadcrumbStatus": {
"type": "string"
},
"claim": {
"type": "object"
},
"pricing": {
"type": "object"
},
"receiptUrl": {
"type": "string"
}
},
"required": [
"claim",
"breadcrumbStatus",
"receiptUrl",
"pricing"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
},
"builder-code": {
"info": {
"a": "bc_8kag0yoi"
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"a": {
"description": "App builder code",
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
},
"s": {
"description": "Service builder codes",
"items": {
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
},
"type": "array"
},
"w": {
"description": "Wallet builder code",
"pattern": "^[a-z0-9_]{1,32}$",
"type": "string"
}
},
"type": "object"
}
}
}Use it
curl
curl "https://www.tereno.xyz/api/v1/claims" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://www.tereno.xyz/api/v1/claims");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://www.tereno.xyz/api/v1/claims")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/2461.json, and this resource appears in /discovery/resources and /discovery/search.