Twenty-Four answer check — verifies a 24-game arithmetic expression with exact rational ma
Twenty-Four answer check — verifies a 24-game arithmetic expression with exact rational math against the deterministic daily challenge.
5000 (raw units)
price
8
calls / 30d
5
unique payers
2026-09-15
updated
Provider
agent-arcade.use.x402atlas.com · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "5000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:137",
"payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"amount": "5000",
"maxTimeoutSeconds": 300
},
{
"scheme": "exact",
"network": "eip155:42161",
"payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"amount": "5000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"category": "games",
"info": {
"input": {
"body": {
"answer": "12*((9-13)+6)",
"challenge_id": "sha256:91ea634735ae4ff57c83ef8f3f08fdecf0b146d41582264bdcbb64b560f36cce",
"date": "2026-07-01",
"difficulty": "normal",
"generation_version": "v1"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"challenge_id": "sha256:91ea634735ae4ff57c83ef8f3f08fdecf0b146d41582264bdcbb64b560f36cce",
"correct": true,
"feedback": {
"message": "correct: the expression evaluates to exactly 24",
"numbers_used": [
12,
9,
13,
6
]
},
"game": "twenty-four",
"proof": {
"exact_value": "24",
"normalized_expression": "(12 * ((9 - 13) + 6))",
"numbers_used": [
12,
9,
13,
6
]
},
"score": 100,
"valid": true
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"description": "Twenty-Four answer-check request using the identity from a daily challenge.",
"properties": {
"answer": {
"description": "Twenty-Four arithmetic expression using each supplied number exactly once with + - * / and parentheses, evaluating to exactly 24",
"maxLength": 256,
"type": "string"
},
"challenge_id": {
"description": "The challenge_id from the daily envelope (sha256:...)",
"pattern": "^sha256:[0-9a-f]{64}$",
"type": "string"
},
"date": {
"description": "UTC challenge date (YYYY-MM-DD)",
"format": "date",
"pattern": "^\\d{4}-\\d{2}-\\d{2}$",
"type": "string"
},
"difficulty": {
"description": "Challenge difficulty",
"enum": [
"normal"
],
"type": "string"
},
"generation_version": {
"description": "Pinned generator version of the referenced challenge",
"enum": [
"v1"
],
"type": "string"
}
},
"required": [
"challenge_id",
"generation_version",
"date",
"difficulty",
"answer"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"additionalProperties": false,
"description": "Twenty-Four answer-check verdict.",
"properties": {
"challenge_id": {
"description": "Canonical ID of the checked challenge",
"type": "string"
},
"correct": {
"description": "The expression solves the challenge (equals 24 exactly)",
"type": "boolean"
},
"feedback": {
"additionalProperties": false,
"description": "Validity feedback; never contains a solution the client did not produce",
"properties": {
"message": {
"type": "string"
},
"numbers_used": {
"items": {
"type": "integer"
},
"type": "array"
}
},
"required": [
"message",
"numbers_used"
],
"type": "object"
},
"game": {
"description": "Twenty-Four game identity.",
"enum": [
"twenty-four"
],
"type": "string"
},
"proof": {
"additionalProperties": false,
"description": "Present only when correct: the client's own verified expression, normalized, with its exact value",
"properties": {
"exact_value": {
"type": "string"
},
"normalized_expression": {
"type": "string"
},
"numbers_used": {
"items": {
"type": "integer"
},
"type": "array"
}
},
"required": [
"normalized_expression",
"exact_value",
"numbers_used"
],
"type": "object"
},
"score": {
"description": "Informational score: 100 correct, 0 otherwise",
"type": "integer"
},
"valid": {
"description": "The expression follows the rules",
"type": "boolean"
}
},
"required": [
"challenge_id",
"game",
"valid",
"correct",
"score",
"feedback"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
},
"tags": [
"twenty-four",
"24-game",
"math-puzzle",
"arithmetic",
"reasoning",
"agent-benchmark",
"answer-check"
]
}
}Use it
curl
curl "https://agent-arcade.use.x402atlas.com/twenty-four/check" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://agent-arcade.use.x402atlas.com/twenty-four/check");
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://agent-arcade.use.x402atlas.com/twenty-four/check")
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/2219.json, and this resource appears in /discovery/resources and /discovery/search.