561 Group Market

Brokerage Issuer Evidence

Dated, source-grounded public-company evidence packet: every claim cites a content-addressed source digest.

Price
$0.25 USDC per request
Network
Base mainnet, eip155:8453, settled in USDC through the Coinbase CDP facilitator
Method and URL
POST https://market.561.group/v1/issuer-evidence
Response type
application/json
Seller
Causeway Services (561 Group)

Input contract

Input that fails this contract is refused with a 4xx status before any payment is requested.

{
  "maxBytes": 102400,
  "bodySchema": {
    "type": "object",
    "properties": {
      "request": {
        "type": "object",
        "required": [
          "ticker",
          "issuer",
          "asOf",
          "sources",
          "claims"
        ],
        "properties": {
          "ticker": {
            "type": "string"
          },
          "issuer": {
            "type": "string"
          },
          "asOf": {
            "type": "string"
          },
          "sources": {
            "type": "array",
            "minItems": 1
          },
          "claims": {
            "type": "array",
            "minItems": 1
          },
          "events": {
            "type": "array"
          },
          "license": {
            "type": "string"
          }
        }
      }
    },
    "required": [
      "request"
    ]
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/issuer-evidence",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "request": {
      "ticker": "AAPL",
      "issuer": "Apple Inc.",
      "asOf": "2026-01-01T00:00:00Z",
      "sources": [
        {
          "uri": "https://www.sec.gov/Archives/edgar/data/example",
          "observedAt": "2026-01-01T00:00:00Z",
          "digest": "sha256:public-example-source"
        }
      ],
      "claims": [
        {
          "statement": "Public example claim for API discovery only.",
          "sourceDigests": [
            "sha256:public-example-source"
          ]
        }
      ]
    }
  }
}

Output

{
  "schema": {
    "type": "object",
    "required": [
      "id",
      "type",
      "ticker",
      "issuer",
      "sources",
      "claims"
    ],
    "properties": {
      "id": {
        "type": "string"
      },
      "type": {
        "const": "IssuerEvidencePacket"
      },
      "ticker": {
        "type": "string"
      },
      "issuer": {
        "type": "string"
      },
      "sources": {
        "type": "array"
      },
      "claims": {
        "type": "array"
      },
      "proofStatus": {
        "type": "string"
      },
      "brokerageEffect": {
        "const": false
      }
    }
  },
  "example": {
    "id": "ni:///sha-256;Zv9TWfzqWRNaqKPhes3xyPUPYCbEbMSHJXHVLRId0G8",
    "type": "IssuerEvidencePacket",
    "version": 1,
    "ticker": "AAPL",
    "issuer": "Apple Inc.",
    "asOf": "2026-01-01T00:00:00Z",
    "sources": [
      {
        "uri": "https://www.sec.gov/Archives/edgar/data/example",
        "observedAt": "2026-01-01T00:00:00Z",
        "digest": "sha256:public-example-source"
      }
    ],
    "claims": [
      {
        "statement": "Public example claim for API discovery only.",
        "sourceDigests": [
          "sha256:public-example-source"
        ]
      }
    ],
    "events": [],
    "license": "single-customer-analysis",
    "proofStatus": "research-evidence-not-mathematical-proof",
    "brokerageEffect": false
  }
}

How to buy with x402

  1. Send the request without payment. The server answers 402 Payment Required with a base64 JSON PAYMENT-REQUIRED header holding the amount, asset, network and payee.
  2. Have your wallet sign an EIP-3009 transferWithAuthorization for exactly those terms (an x402 client library does this for you).
  3. Repeat the identical request with the signed payload in the PAYMENT-SIGNATURE header.
  4. The server verifies, runs the operation, settles, and returns 200 with the result and a PAYMENT-RESPONSE header carrying the settlement receipt.

Read the price without paying

curl --include --request POST --header 'accept: application/json' --header 'content-type: application/json' --data-raw '{"request":{"ticker":"AAPL","issuer":"Apple Inc.","asOf":"2026-01-01T00:00:00Z","sources":[{"uri":"https://www.sec.gov/Archives/edgar/data/example","observedAt":"2026-01-01T00:00:00Z","digest":"sha256:public-example-source"}],"claims":[{"statement":"Public example claim for API discovery only.","sourceDigests":["sha256:public-example-source"]}]}}' --url 'https://market.561.group/v1/issuer-evidence'

This request authorizes nothing; it returns the live payment terms. Read the full explanation of x402.

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