Saylor Innovations Data Desk

Name: Saylor Innovations Data Desk
Price: 0.01 USDC
Availability: InStock

NFT holdings check on 16 EVM chains: how many tokens a wallet holds in each of up to 10 ERC-721 collections, with collection names and symbols.

DataLiveeip155:8453Exactvia cdp

https://saylorinnovations.com/api/chain/nft-holdings

Nft holdings checkDoes wallet own collectionerc721 balanceof manyNft gate checkWallet nft count

Calls · 30d

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 6 snapshots so far.

$15.76

Verified settled volume

1,657 settlements proven x402 by their on-chain EIP-3009 marker.

$0.010

Listed price

As published in the catalog. Always read the live 402 before paying.

Calls · 30d

Upstream's own call count for this endpoint, not ours.

Unique payers · 30d

Last called 2026-10-23 00:02Z

—

Upstream on-chain volume

Reported by the source catalog.

Paid to

0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "error": "Payment required to access this resource.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "name": "USD Coin",
        "note": "Base settles through an x402 facilitator. Send payload.signature and payload.authorization (EIP-3009); there is no self-submitted path on this network.",
        "version": "2",
        "facilitatorOnly": true,
        "assetTransferMethod": "eip3009"
      },
      "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 120
    },
    {
      "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "name": "USD Coin",
        "note": "Polygon settles through an x402 facilitator. Send payload.signature and payload.authorization (EIP-3009); there is no self-submitted path on this network.",
        "version": "2",
        "facilitatorOnly": true,
        "assetTransferMethod": "eip3009"
      },
      "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:137",
      "maxTimeoutSeconds": 120
    },
    {
      "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "name": "USD Coin",
        "note": "Arbitrum settles through an x402 facilitator. Send payload.signature and payload.authorization (EIP-3009); there is no self-submitted path on this network.",
        "version": "2",
        "facilitatorOnly": true,
        "assetTransferMethod": "eip3009"
      },
      "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:42161",
      "maxTimeoutSeconds": 120
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "session": "eyJhcnRpY2xlSWQiOiJkYXRhZGVzazpjaGFpbi1uZnQtaG9sZGluZ3MiLCJyZWZlcmVuY2UiOiI3NGZkQ3VRS2pjN0tqRXFXa3dleUZYY3ZybnJlSnhzaTVneEY4WnptUjRaQSIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6IkVQakZXZGQ1QXVmcVNTcWVNMnFOMXh6eWJhcEM4RzR3RUdHa1p3eVREdDF2IiwibWluQW1vdW50IjoxMDAwMCwiZXhwIjoxNzkyNTU4MDYwODEyfQ.yUb1QNiHr_t5IED2mk175zCgdp7JFmCAFS7WyLi5JS8",
        "feePayer": "BFK9TLC3edb13K6v4YyH3DwPb5DSUpkWvb7XnqCL9b4F",
        "reference": "74fdCuQKjc7KjEqWkweyFXcvrnreJxsi5gxF8ZzmR4ZA"
      },
      "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 120
    },
    {
      "asset": "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "session": "eyJhcnRpY2xlSWQiOiJkYXRhZGVzazpjaGFpbi1uZnQtaG9sZGluZ3MiLCJyZWZlcmVuY2UiOiI1enR5RHVReGV1elJwWDljdkc0QzdkSEdFZ0FGWGl5V3hUUmZGZnAzR0gzNCIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6IkVzOXZNRnJ6YUNFUm1KZnJGNEgyRllENEtDb05rWTExTWNDZThCZW53TllCIiwibWluQW1vdW50IjoxMDAwMCwiZXhwIjoxNzkyNTU4MDYwODEzfQ.JkYpRtfUrgMSppOsOLyqIot2gw2_9DO4ZaP_OKuWZC0",
        "feePayer": "BFK9TLC3edb13K6v4YyH3DwPb5DSUpkWvb7XnqCL9b4F",
        "reference": "5ztyDuQxeuzRpX9cvG4C7dHGEgAFXiyWxTRfFfp3GH34"
      },
      "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 120
    },
    {
      "asset": "So11111111111111111111111111111111111111112",
      "extra": {
        "memo": "saylor:datadesk:chain-nft-holdin",
        "note": "Native SOL: send lamports with a system transfer, not an SPL transfer. Price is quoted live and this quote expires in 120s.",
        "native": true,
        "session": "eyJhcnRpY2xlSWQiOiJkYXRhZGVzazpjaGFpbi1uZnQtaG9sZGluZ3MiLCJyZWZlcmVuY2UiOiIzRGFrQnJnRWZTelpmb2FibmZyeFZVQlRYYzF3VzR2NFNMYmFIaE1NdDRCRyIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6bnVsbCwibWluQW1vdW50Ijo5MTgxMiwiZXhwIjoxNzkyNTU4MDYwODEzfQ.XV6F4rlEiDFMA4ARB_jqgZVWcoUrMjVpL0OsHZwMYH0",
        "reference": "3DakBrgEfSzZfoabnfrxVUBTXc1wW4v4SLbaHhMMt4BG",
        "solUsdPrice": 105.65,
        "quotedLamports": "94652"
      },
      "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
      "amount": "91812",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 120
    }
  ],
  "resource": {
    "url": "https://saylorinnovations.com/api/chain/nft-holdings?chain=ethereum&owner=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045&collections=0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D,0x60E4d786628Fea6478F785A6d7e704777c86a7c6",
    "tags": [
      "nft holdings check",
      "does wallet own collection",
      "erc721 balanceof many",
      "nft gate check",
      "wallet nft count"
    ],
    "iconUrl": "https://saylorinnovations.com/og-image.jpg",
    "mimeType": "application/json",
    "description": "NFT holdings check on 16 EVM chains: how many tokens a wallet holds in each of up to 10 ERC-721 collections, with collection names and symbols.",
    "serviceName": "Saylor Innovations Data Desk"
  },
  "extensions": {
    "tags": [
      "nft holdings check",
      "does wallet own collection",
      "erc721 balanceof many",
      "nft gate check",
      "wallet nft count"
    ],
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "chain": "ethereum",
            "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
            "collections": "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D,0x60E4d786628Fea6478F785A6d7e704777c86a7c6"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "note": "ERC-721 balanceOf(owner) for each collection you listed. ERC-1155 collections have per-id balances and are not covered here; use erc1155-balance for those.",
            "chain": "ethereum",
            "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
            "source": "Chain JSON-RPC (ethereum)",
            "chain_id": 1,
            "holdings": [
              {
                "name": "BoredApeYachtClub",
                "holds": true,
                "status": "holds",
                "symbol": "BAYC",
                "balance": "1",
                "collection": "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D",
                "erc721_confirmed": true
              },
              {
                "name": "MutantApeYachtClub",
                "holds": false,
                "status": "none",
                "symbol": "MAYC",
                "balance": "0",
                "collection": "0x60E4d786628Fea6478F785A6d7e704777c86a7c6",
                "erc721_confirmed": true
              }
            ],
            "total_tokens": 1,
            "collections_held": 1,
            "collections_checked": 2
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "chain",
                  "owner",
                  "collections"
                ],
                "properties": {
                  "chain": {
                    "type": "string",
                    "description": "chain name (ethereum, base, arbitrum, optimism, polygon, bsc, avalanche, gnosis, linea, scroll, mantle, blast, sonic, celo, berachain, unichain) or chain id"
                  },
                  "owner": {
                    "type": "string",
                    "description": "the wallet to check"
                  },
                  "collections": {
                    "type": "string",
                    "description": "comma-separated ERC-721 collection contracts, 1 to 10"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "json"
              },
              "example": {
                "type": "object",
                "required": [
                  "chain",
                  "chain_id",
                  "owner",
                  "collections_checked",
                  "collections_held",
                  "holdings",
                  "note",
                  "source"
                ],
                "properties": {
                  "note": {
                    "type": "string",
                    "description": "plain-language reading of the result"
                  },
                  "chain": {
                    "type": "string",
                    "description": "the chain name that was queried"
                  },
                  "owner": {
                    "type": "string",
                    "description": "wallet checked"
                  },
                  "source": {
                    "type": "string",
                    "description": "where the data was read from or how it was computed"
                  },
                  "chain_id": {
                    "type": "number",
                    "description": "EIP-155 chain id of that network"
                  },
                  "holdings": {
                    "type": [
                      "array",
                      "null"
                    ],
                    "items": {
                      "type": "object",
                      "properties": {
                        "name": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "collection name"
                        },
                        "holds": {
                          "type": [
                            "boolean",
                            "null"
                          ],
                          "description": "true when balance is above zero"
                        },
                        "status": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "holds, none or not_an_erc721_collection_here"
                        },
                        "symbol": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "collection symbol"
                        },
                        "balance": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "tokens held"
                        },
                        "collection": {
                          "type": [
                            "string",
                            "null"
                          ],
                          "description": "collection contract"
                        },
                        "erc721_confirmed": {
                          "type": [
                            "boolean",
                            "null"
                          ],
                          "description": "true when the contract confirms ERC-721 via ERC-165"
                        }
                      }
                    },
                    "description": "one entry per collection"
                  },
                  "total_tokens": {
                    "type": "number",
                    "description": "tokens held across the collections"
                  },
                  "collections_held": {
                    "type": "number",
                    "description": "collections the wallet holds at least one token in"
                  },
                  "collections_checked": {
                    "type": "number",
                    "description": "collections read"
                  }
                }
              }
            }
          }
        }
      }
    },
    "method": "GET",
    "example": {
      "note": "ERC-721 balanceOf(owner) for each collection you listed. ERC-1155 collections have per-id balances and are not covered here; use erc1155-balance for those.",
      "chain": "ethereum",
      "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
      "source": "Chain JSON-RPC (ethereum)",
      "chain_id": 1,
      "holdings": [
        {
          "name": "BoredApeYachtClub",
          "holds": true,
          "status": "holds",
          "symbol": "BAYC",
          "balance": "1",
          "collection": "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D",
          "erc721_confirmed": true
        },
        {
          "name": "MutantApeYachtClub",
          "holds": false,
          "status": "none",
          "symbol": "MAYC",
          "balance": "0",
          "collection": "0x60E4d786628Fea6478F785A6d7e704777c86a7c6",
          "erc721_confirmed": true
        }
      ],
      "total_tokens": 1,
      "collections_held": 1,
      "collections_checked": 2
    },
    "license": "LicenseRef-Saylor-Agent-Use-1.0",
    "mimeType": "application/json",
    "freshness": "fetched live (cached up to 1 hour for large reference files)",
    "tokenCount": null,
    "inputSchema": {
      "chain": "chain name (ethereum, base, arbitrum, optimism, polygon, bsc, avalanche, gnosis, linea, scroll, mantle, blast, sonic, celo, berachain, unichain) or chain id",
      "owner": "the wallet to check",
      "collections": "comma-separated ERC-721 collection contracts, 1 to 10"
    },
    "serviceName": "Saylor Innovations Data Desk",
    "instructions": "STANDARD PATH (works with stock x402 clients): send payload.transaction — a base64 partially-signed Solana transaction — and we route verify/settle through an x402 facilitator that sponsors the fee and submits it. Include the chosen accepts entry as \"accepted\" so we can match terms. ALTERNATIVE PATH (no facilitator): Pick ONE entry from accepts and use the reference and session from THAT entry — each asset has its own. USDC or USDT: send an SPL transfer of the exact amount. Native SOL (asset=So11111111111111111111111111111111111111112, extra.native=true): send that many lamports with a system transfer. Either way include extra.reference as a read-only account (Solana Pay style), then retry with PAYMENT-SIGNATURE: base64({x402Version:2, payload:{session, reference}}). If your client cannot attach a reference, send payload.signature instead (USDC only). SOL amounts are quoted live and expire in 120s; stablecoins do not move. The facilitator path verifies and settles in this request. Only the alternative self-submitted Solana path needs retries while the transfer is indexed (typically 3-4 attempts over 10-20s). On that path, a 402 saying \"payment not found on-chain yet\" means keep retrying.",
    "outputSchema": {
      "type": "object",
      "required": [
        "chain",
        "chain_id",
        "owner",
        "collections_checked",
        "collections_held",
        "holdings",
        "note",
        "source"
      ],
      "properties": {
        "note": {
          "type": "string",
          "description": "plain-language reading of the result"
        },
        "chain": {
          "type": "string",
          "description": "the chain name that was queried"
        },
        "owner": {
          "type": "string",
          "description": "wallet checked"
        },
        "source": {
          "type": "string",
          "description": "where the data was read from or how it was computed"
        },
        "chain_id": {
          "type": "number",
          "description": "EIP-155 chain id of that network"
        },
        "holdings": {
          "type": [
            "array",
            "null"
          ],
          "items": {
            "type": "object",
            "properties": {
              "name": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "collection name"
              },
              "holds": {
                "type": [
                  "boolean",
                  "null"
                ],
                "description": "true when balance is above zero"
              },
              "status": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "holds, none or not_an_erc721_collection_here"
              },
              "symbol": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "collection symbol"
              },
              "balance": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "tokens held"
              },
              "collection": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "collection contract"
              },
              "erc721_confirmed": {
                "type": [
                  "boolean",
                  "null"
                ],
                "description": "true when the contract confirms ERC-721 via ERC-165"
              }
            }
          },
          "description": "one entry per collection"
        },
        "total_tokens": {
          "type": "number",
          "description": "tokens held across the collections"
        },
        "collections_held": {
          "type": "number",
          "description": "collections the wallet holds at least one token in"
        },
        "collections_checked": {
          "type": "number",
          "description": "collections read"
        }
      }
    },
    "noPathTemplate": true,
    "settlementModes": [
      "facilitator-transaction",
      "self-submitted-reference"
    ],
    "typicalLatencyMs": 700
  },
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

0.01USDC≈ $0.01 USD

on Base · exact scheme

Pay 0.01 USDC on Base to 0xA2A8…fc8aa. The signed payment is good for 2 minutes.

Paid to: 0xA2A8…fc8aa
USD Coin contract: 0x8335…02913
Payment window: 2 minutes
As published: 10000 smallest units

10000units

on Polygon · exact scheme