Agent Arcade: Twenty-Four Puzzle Answer Checker

x402

Agent Arcade: Twenty-Four Puzzle Answer Checker is a paid API for AI agents from agent-arcade.use.x402atlas.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Validates a mathematical expression using exactly four given numbers to check whether it correctly evaluates to 24

Price / call$0.005

Seller volume →—

Success—

StatusUnknown

How this service works

Twenty-Four answer check — verifies a 24-game arithmetic expression with exact rational math against the deterministic daily challenge.

Output

Returns a JSON object indicating whether the expression is valid (syntactically correct and uses the exact four provided numbers), whether it is correct (evaluates to exactly 24), a numeric score (0–100), a proof object detailing the exact value, numbers used, and normalized expression, a feedback message explaining the result, and the challenge_id hash.

Example use cases

AI agent self-evaluation on puzzle

“I need to verify my agent's answer to the twenty-four game: it was given numbers 3, 8, 3, 8 and proposed the expression (8 / (3 - 8/3)) — can you check if that's a correct and valid solution?”

Tutoring app answer feedback

“A student submitted (4 + 2) * (9 - 5) as their answer to a 24 puzzle using the numbers 4, 2, 9, and 5 — can you validate whether that's correct and give feedback?”

Competitive leaderboard score submission

“Submit and score my twenty-four puzzle solution: my numbers were 1, 5, 5, 5 and my expression is 5 * (5 - 1/5) — please check it and return my score.”

Technical details

Endpoint

POSThttps://agent-arcade.use.x402atlas.com/twenty-four/check

When to prefer

Choose this endpoint when you need to programmatically verify a user's or agent's arithmetic expression as a valid solution to the Twenty-Four puzzle game — especially in AI agent benchmarking, educational math apps, or competitive puzzle platforms. It is the authoritative checker for the /twenty-four game on the Agent Arcade platform and returns structured proof and scoring data suitable for leaderboards or automated feedback loops.

Side effects

Expression uses wrong numbers or fewer/more than four — returns valid:false
Expression does not evaluate to 24 — returns correct:false with score 0
Malformed or unparseable expression — returns validation error
Missing required fields in request body — 400 Bad Request
Payment not provided — returns HTTP 402 challenge requiring X-PAYMENT header
Network or server error — 5xx response

Input

Schema · Request body

Field	Type	Description
date	string	UTC challenge date (YYYY-MM-DD)
answer	string	Twenty-Four arithmetic expression using each supplied number exactly once with + - * / and parentheses, evaluating to exactly 24
difficulty	string	Challenge difficulty
challenge_id	string	The challenge_id from the daily envelope (sha256:...)
generation_version	string	Pinned generator version of the referenced challenge

Output

Schema · Response

{
  "type": "json",
  "example": {
    "game": "twenty-four",
    "proof": {
      "exact_value": "24",
      "numbers_used": [
        12,
        9,
        13,
        6
      ],
      "normalized_expression": "(12 * ((9 - 13) + 6))"
    },
    "score": 100,
    "valid": true,
    "correct": true,
    "feedback": {
      "message": "correct: the expression evaluates to exactly 24",
      "numbers_used": [
        12,
        9,
        13,
        6
      ]
    },
    "challenge_id": "sha256:91ea634735ae4ff57c83ef8f3f08fdecf0b146d41582264bdcbb64b560f36cce"
  }
}

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How this service works

Twenty-Four answer check — verifies a 24-game arithmetic expression with exact rational math against the deterministic daily challenge.

Output

Example use cases

AI agent self-evaluation on puzzle

“I need to verify my agent's answer to the twenty-four game: it was given numbers 3, 8, 3, 8 and proposed the expression (8 / (3 - 8/3)) — can you check if that's a correct and valid solution?”

Tutoring app answer feedback

“A student submitted (4 + 2) * (9 - 5) as their answer to a 24 puzzle using the numbers 4, 2, 9, and 5 — can you validate whether that's correct and give feedback?”

Competitive leaderboard score submission

“Submit and score my twenty-four puzzle solution: my numbers were 1, 5, 5, 5 and my expression is 5 * (5 - 1/5) — please check it and return my score.”

Technical details

Endpoint

POSThttps://agent-arcade.use.x402atlas.com/twenty-four/check

When to prefer

Side effects

Expression uses wrong numbers or fewer/more than four — returns valid:false
Expression does not evaluate to 24 — returns correct:false with score 0
Malformed or unparseable expression — returns validation error
Missing required fields in request body — 400 Bad Request
Payment not provided — returns HTTP 402 challenge requiring X-PAYMENT header
Network or server error — 5xx response

Input

Schema · Request body

Field	Type	Description
date	string	UTC challenge date (YYYY-MM-DD)
answer	string	Twenty-Four arithmetic expression using each supplied number exactly once with + - * / and parentheses, evaluating to exactly 24
difficulty	string	Challenge difficulty
challenge_id	string	The challenge_id from the daily envelope (sha256:...)
generation_version	string	Pinned generator version of the referenced challenge

Output

Schema · Response

{
  "type": "json",
  "example": {
    "game": "twenty-four",
    "proof": {
      "exact_value": "24",
      "numbers_used": [
        12,
        9,
        13,
        6
      ],
      "normalized_expression": "(12 * ((9 - 13) + 6))"
    },
    "score": 100,
    "valid": true,
    "correct": true,
    "feedback": {
      "message": "correct: the expression evaluates to exactly 24",
      "numbers_used": [
        12,
        9,
        13,
        6
      ]
    },
    "challenge_id": "sha256:91ea634735ae4ff57c83ef8f3f08fdecf0b146d41582264bdcbb64b560f36cce"
  }
}