How a check works

Two models from rival labs answer each check blind, and SECONDED signs the result.

Degen Check is the exception: agents pay $0.10 for a signed disagreement, which shows both reads.

The call and the receipt

One MCP call, or one HTTP request paid over x402, returns the answer with its signed receipt.

MCP HTTP over x402

Request

seconded_token_check
{
  "input": {
    "network": "eip155:8453",
    "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913"
  },
  "max_price_usd": "0.10"
}

Signed receipt in the tool result

{
  "envelope": {
    "v": 3,
    "kind": "seconded-receipt",
    "check_id": "17c5a4d15f0aeac58217ede888ba495b",
    …
    "product": "token_check",
    …
    "checked_by": ["OpenAI", "Anthropic"],
    …
    "outcome": "agreed",
    …
    "answer": {
      "option": 5,
      "label_id": "issuer_controlled_expected",
      …
    },
    "key_id": "rk-2026-09-a"
  },
  "sig": "VJIxJUbXK4qQ…hunQR-nDw",
  "key_id": "rk-2026-09-a"
}

Request

POST https://api.secondedoracle.xyz/v1/x402/checks
SECONDED-CLIENT-VERSION: …
PAYMENT-SIGNATURE: …

{
  "product": "token_check",
  "input": {
    "network": "eip155:8453",
    "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913"
  },
  "options": {"network": "eip155:8453"}
}

Response, HTTP 200

{
  "receipt": {
    "envelope": {
      "v": 3,
      "kind": "seconded-receipt",
      "check_id": "17c5a4d15f0aeac58217ede888ba495b",
      …
      "product": "token_check",
      …
      "checked_by": ["OpenAI", "Anthropic"],
      …
      "outcome": "agreed",
      …
      "billing": {
        "mode": "paid",
        "charged": "yes",
        …
        "tx": "0xb27e710b…d5f6cb98",
        …
      },
      …
      "answer": {
        "option": 5,
        "label_id": "issuer_controlled_expected",
        …
      },
      "key_id": "rk-2026-09-a"
    },
    "sig": "VJIxJUbXK4qQ…hunQR-nDw",
    "key_id": "rk-2026-09-a"
  },
  "hints": {"do_not_resign": true, …}
}

The paid Token Check behind the receipt on the home page. HTTP: captured from the live API on October 19, 2026, trimmed with an ellipsis. MCP: the same input as a tool call, and the receipt its result carries.

When the models disagree

The result is NOT VERIFIED, signed and not charged, except on Degen Check. The same holds when a fact SECONDED verified contradicts a “proceed”. Each wallet gets up to 5 free NOT VERIFIED results in any rolling 24 hours. A service failure is also signed and free.

Check the signature

Every receipt is signed with Ed25519 under a published key, such as rk-2026-09-a. Verify it before your agent acts on the answer.

Verify a receipt