{
  "x402Version": 2,
  "id": 28613,
  "slug": "28613",
  "resource": "https://verifiable-random.use.x402atlas.com/pick",
  "description": "Verifiable Random pick — string selection with or without replacement bound to a future drand round the server waits for (typically 3-6s) and verifies locally, with a reproducible proof transcript.",
  "type": "http",
  "serviceName": "Verifiable Random Tools",
  "resourceType": "Utilities",
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:8453",
      "payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "amount": "5000",
      "amountUsd": 0.005,
      "maxTimeoutSeconds": 300
    },
    {
      "scheme": "exact",
      "network": "eip155:137",
      "payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
      "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
      "amount": "5000",
      "amountUsd": 0.005,
      "maxTimeoutSeconds": 300
    },
    {
      "scheme": "exact",
      "network": "eip155:42161",
      "payTo": "0x8C128f1Ee62Bb5e47867CfbAe2ad89be325Df1b2",
      "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
      "amount": "5000",
      "amountUsd": 0.005,
      "maxTimeoutSeconds": 300
    },
    {
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "payTo": "ASt6xvRyQ7ntERsmcYVMdLqZvz1GEN8Fzexzq62tXrNQ",
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "amount": "5000",
      "amountUsd": 0.005,
      "maxTimeoutSeconds": 300
    }
  ],
  "outputSchema": {
    "properties": {
      "example": {
        "additionalProperties": false,
        "description": "Verifiable Random result and complete drand derivation transcript.",
        "properties": {
          "algorithm_version": {
            "description": "Pinned canonicalization, derivation, and sampling algorithm version required to reproduce the result.",
            "enum": [
              "drand-hkdf-sha256-v1"
            ],
            "type": "string"
          },
          "beacon": {
            "additionalProperties": false,
            "description": "Locally verified drand Quicknet proof used as the public randomness source.",
            "properties": {
              "chain_hash": {
                "description": "Pinned Quicknet chain hash used to fetch and verify the round.",
                "enum": [
                  "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971"
                ],
                "type": "string"
              },
              "network": {
                "description": "Pinned drand network name.",
                "enum": [
                  "quicknet"
                ],
                "type": "string"
              },
              "randomness": {
                "description": "Lowercase hexadecimal randomness derived from the verified signature.",
                "pattern": "^[0-9a-f]{64}$",
                "type": "string"
              },
              "round": {
                "description": "Exact verified Quicknet round used for this result.",
                "minimum": 1,
                "type": "integer"
              },
              "scheduled_time": {
                "description": "Scheduled UTC publication time of the selected round.",
                "format": "date-time",
                "type": "string"
              },
              "scheme": {
                "description": "Pinned drand signature scheme.",
                "enum": [
                  "bls-unchained-g1-rfc9380"
                ],
                "type": "string"
              },
              "signature": {
                "description": "Lowercase hexadecimal BLS signature verified against the pinned Quicknet public key.",
                "pattern": "^[0-9a-f]{96}$",
                "type": "string"
              }
            },
            "required": [
              "network",
              "chain_hash",
              "scheme",
              "round",
              "scheduled_time",
              "randomness",
              "signature"
            ],
            "type": "object"
          },
          "example_only": {
            "description": "True only in compiled catalog/keepalive examples; live paid results are false.",
            "type": "boolean"
          },
          "operation": {
            "description": "Random operation performed by this route.",
            "enum": [
              "pick"
            ],
            "type": "string"
          },
          "processed_at": {
            "description": "UTC time when the service accepted the request and committed to the round-selection decision.",
            "format": "date-time",
            "type": "string"
          },
          "request_hash": {
            "description": "Lowercase SHA-256 of your canonical request JSON — retain the exact request body so you can re-derive the result offline.",
            "pattern": "^[0-9a-f]{64}$",
            "type": "string"
          },
          "result": {
            "additionalProperties": false,
            "description": "Operation-specific result derived deterministically from the verified beacon and request hash.",
            "properties": {
              "items": {
                "description": "Selected strings in draw order.",
                "items": {
                  "type": "string"
                },
                "type": "array"
              },
              "original_indices": {
                "description": "For each selected value, its zero-based position in the input array.",
                "items": {
                  "type": "integer"
                },
                "type": "array"
              }
            },
            "required": [
              "items",
              "original_indices"
            ],
            "type": "object"
          },
          "selection_mode": {
            "description": "server_next means the server chose the next safe unpublished round, so you trust its selection chronology; client_fixed means the round is the one you committed to before paying and no other round can be substituted; example_only appears only in catalog examples.",
            "enum": [
              "server_next",
              "client_fixed",
              "example_only"
            ],
            "type": "string"
          },
          "target_round": {
            "description": "Echoes the round actually selected for this result; in server_next mode this is the server-chosen round, not the 0 you sent.",
            "minimum": 1,
            "type": "integer"
          }
        },
        "required": [
          "operation",
          "algorithm_version",
          "selection_mode",
          "target_round",
          "example_only",
          "processed_at",
          "request_hash",
          "beacon",
          "result"
        ],
        "type": "object"
      },
      "type": {
        "type": "string"
      }
    },
    "required": [
      "type"
    ],
    "type": "object"
  },
  "extensions": {
    "bazaar": {
      "category": "utilities",
      "info": {
        "input": {
          "body": {
            "algorithm_version": "drand-hkdf-sha256-v1",
            "client_seed": "example",
            "count": 2,
            "items": [
              "red",
              "green",
              "blue"
            ],
            "replacement": false,
            "target_round": 0
          },
          "bodyType": "json",
          "method": "POST",
          "type": "http"
        },
        "output": {
          "example": {
            "algorithm_version": "drand-hkdf-sha256-v1",
            "beacon": {
              "chain_hash": "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971",
              "network": "quicknet",
              "randomness": "1466a6cd24e327188770752f6134001c64d6efcc590ccc26b721611ad96f165a",
              "round": 1,
              "scheduled_time": "2023-08-23T15:09:27Z",
              "scheme": "bls-unchained-g1-rfc9380",
              "signature": "b55e7cb2d5c613ee0b2e28d6750aabbb78c39dcc96bd9d38c2c2e12198df95571de8e8e402a0cc48871c7089a2b3af4b"
            },
            "example_only": true,
            "operation": "pick",
            "processed_at": "2023-08-23T15:09:27Z",
            "request_hash": "bf26799b7b70582f93b7ab7e9ea1428d812387b32e3177c521ed38f09306abcc",
            "result": {
              "items": [
                "red",
                "green"
              ],
              "original_indices": [
                0,
                1
              ]
            },
            "selection_mode": "example_only",
            "target_round": 1
          },
          "type": "json"
        }
      },
      "schema": {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "properties": {
          "input": {
            "additionalProperties": false,
            "properties": {
              "body": {
                "additionalProperties": false,
                "description": "String selection request bound to a future drand round.",
                "properties": {
                  "algorithm_version": {
                    "default": "drand-hkdf-sha256-v1",
                    "description": "Optional version guard; when supplied it must match the server's pinned derivation algorithm.",
                    "enum": [
                      "drand-hkdf-sha256-v1"
                    ],
                    "type": "string"
                  },
                  "client_seed": {
                    "default": "",
                    "description": "Optional public domain-separation label, not secret entropy.",
                    "maxLength": 256,
                    "type": "string"
                  },
                  "count": {
                    "description": "Number of values to select.",
                    "maximum": 1000,
                    "minimum": 1,
                    "type": "integer"
                  },
                  "items": {
                    "description": "Candidate strings to select from, at most 131072 UTF-8 bytes combined; duplicate values are allowed and remain distinguishable by original_indices.",
                    "items": {
                      "maxLength": 256,
                      "type": "string"
                    },
                    "maxItems": 1000,
                    "minItems": 1,
                    "type": "array"
                  },
                  "replacement": {
                    "default": false,
                    "description": "False selects each input position at most once; true makes independent draws and permits repeated positions.",
                    "type": "boolean"
                  },
                  "target_round": {
                    "default": 0,
                    "description": "0 asks the server to choose the next safe unpublished round; a positive value makes a client_fixed commitment and must still be safely in the future.",
                    "minimum": 0,
                    "type": "integer"
                  }
                },
                "required": [
                  "items",
                  "count"
                ],
                "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": "Verifiable Random result and complete drand derivation transcript.",
                "properties": {
                  "algorithm_version": {
                    "description": "Pinned canonicalization, derivation, and sampling algorithm version required to reproduce the result.",
                    "enum": [
                      "drand-hkdf-sha256-v1"
                    ],
                    "type": "string"
                  },
                  "beacon": {
                    "additionalProperties": false,
                    "description": "Locally verified drand Quicknet proof used as the public randomness source.",
                    "properties": {
                      "chain_hash": {
                        "description": "Pinned Quicknet chain hash used to fetch and verify the round.",
                        "enum": [
                          "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971"
                        ],
                        "type": "string"
                      },
                      "network": {
                        "description": "Pinned drand network name.",
                        "enum": [
                          "quicknet"
                        ],
                        "type": "string"
                      },
                      "randomness": {
                        "description": "Lowercase hexadecimal randomness derived from the verified signature.",
                        "pattern": "^[0-9a-f]{64}$",
                        "type": "string"
                      },
                      "round": {
                        "description": "Exact verified Quicknet round used for this result.",
                        "minimum": 1,
                        "type": "integer"
                      },
                      "scheduled_time": {
                        "description": "Scheduled UTC publication time of the selected round.",
                        "format": "date-time",
                        "type": "string"
                      },
                      "scheme": {
                        "description": "Pinned drand signature scheme.",
                        "enum": [
                          "bls-unchained-g1-rfc9380"
                        ],
                        "type": "string"
                      },
                      "signature": {
                        "description": "Lowercase hexadecimal BLS signature verified against the pinned Quicknet public key.",
                        "pattern": "^[0-9a-f]{96}$",
                        "type": "string"
                      }
                    },
                    "required": [
                      "network",
                      "chain_hash",
                      "scheme",
                      "round",
                      "scheduled_time",
                      "randomness",
                      "signature"
                    ],
                    "type": "object"
                  },
                  "example_only": {
                    "description": "True only in compiled catalog/keepalive examples; live paid results are false.",
                    "type": "boolean"
                  },
                  "operation": {
                    "description": "Random operation performed by this route.",
                    "enum": [
                      "pick"
                    ],
                    "type": "string"
                  },
                  "processed_at": {
                    "description": "UTC time when the service accepted the request and committed to the round-selection decision.",
                    "format": "date-time",
                    "type": "string"
                  },
                  "request_hash": {
                    "description": "Lowercase SHA-256 of your canonical request JSON — retain the exact request body so you can re-derive the result offline.",
                    "pattern": "^[0-9a-f]{64}$",
                    "type": "string"
                  },
                  "result": {
                    "additionalProperties": false,
                    "description": "Operation-specific result derived deterministically from the verified beacon and request hash.",
                    "properties": {
                      "items": {
                        "description": "Selected strings in draw order.",
                        "items": {
                          "type": "string"
                        },
                        "type": "array"
                      },
                      "original_indices": {
                        "description": "For each selected value, its zero-based position in the input array.",
                        "items": {
                          "type": "integer"
                        },
                        "type": "array"
                      }
                    },
                    "required": [
                      "items",
                      "original_indices"
                    ],
                    "type": "object"
                  },
                  "selection_mode": {
                    "description": "server_next means the server chose the next safe unpublished round, so you trust its selection chronology; client_fixed means the round is the one you committed to before paying and no other round can be substituted; example_only appears only in catalog examples.",
                    "enum": [
                      "server_next",
                      "client_fixed",
                      "example_only"
                    ],
                    "type": "string"
                  },
                  "target_round": {
                    "description": "Echoes the round actually selected for this result; in server_next mode this is the server-chosen round, not the 0 you sent.",
                    "minimum": 1,
                    "type": "integer"
                  }
                },
                "required": [
                  "operation",
                  "algorithm_version",
                  "selection_mode",
                  "target_round",
                  "example_only",
                  "processed_at",
                  "request_hash",
                  "beacon",
                  "result"
                ],
                "type": "object"
              },
              "type": {
                "type": "string"
              }
            },
            "required": [
              "type"
            ],
            "type": "object"
          }
        },
        "required": [
          "input"
        ],
        "type": "object"
      },
      "tags": [
        "verifiable-random",
        "random-pick",
        "random-selection",
        "sample",
        "drand",
        "fair-selection"
      ]
    }
  },
  "tags": [
    "verifiable-random",
    "random-pick",
    "random-selection",
    "sample",
    "drand",
    "bazaar"
  ],
  "sourceHost": "verifiable-random.use.x402atlas.com",
  "lastUpdated": "2026-10-08T05:33:19.35Z",
  "quality": {
    "calls30d": 5,
    "uniquePayers30d": 4,
    "lastCalledAt": "2026-10-08T05:33:19.231Z"
  },
  "metadata": {
    "serviceName": "Verifiable Random Tools",
    "extensions": {
      "bazaar": {
        "category": "utilities",
        "info": {
          "input": {
            "body": {
              "algorithm_version": "drand-hkdf-sha256-v1",
              "client_seed": "example",
              "count": 2,
              "items": [
                "red",
                "green",
                "blue"
              ],
              "replacement": false,
              "target_round": 0
            },
            "bodyType": "json",
            "method": "POST",
            "type": "http"
          },
          "output": {
            "example": {
              "algorithm_version": "drand-hkdf-sha256-v1",
              "beacon": {
                "chain_hash": "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971",
                "network": "quicknet",
                "randomness": "1466a6cd24e327188770752f6134001c64d6efcc590ccc26b721611ad96f165a",
                "round": 1,
                "scheduled_time": "2023-08-23T15:09:27Z",
                "scheme": "bls-unchained-g1-rfc9380",
                "signature": "b55e7cb2d5c613ee0b2e28d6750aabbb78c39dcc96bd9d38c2c2e12198df95571de8e8e402a0cc48871c7089a2b3af4b"
              },
              "example_only": true,
              "operation": "pick",
              "processed_at": "2023-08-23T15:09:27Z",
              "request_hash": "bf26799b7b70582f93b7ab7e9ea1428d812387b32e3177c521ed38f09306abcc",
              "result": {
                "items": [
                  "red",
                  "green"
                ],
                "original_indices": [
                  0,
                  1
                ]
              },
              "selection_mode": "example_only",
              "target_round": 1
            },
            "type": "json"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "body": {
                  "additionalProperties": false,
                  "description": "String selection request bound to a future drand round.",
                  "properties": {
                    "algorithm_version": {
                      "default": "drand-hkdf-sha256-v1",
                      "description": "Optional version guard; when supplied it must match the server's pinned derivation algorithm.",
                      "enum": [
                        "drand-hkdf-sha256-v1"
                      ],
                      "type": "string"
                    },
                    "client_seed": {
                      "default": "",
                      "description": "Optional public domain-separation label, not secret entropy.",
                      "maxLength": 256,
                      "type": "string"
                    },
                    "count": {
                      "description": "Number of values to select.",
                      "maximum": 1000,
                      "minimum": 1,
                      "type": "integer"
                    },
                    "items": {
                      "description": "Candidate strings to select from, at most 131072 UTF-8 bytes combined; duplicate values are allowed and remain distinguishable by original_indices.",
                      "items": {
                        "maxLength": 256,
                        "type": "string"
                      },
                      "maxItems": 1000,
                      "minItems": 1,
                      "type": "array"
                    },
                    "replacement": {
                      "default": false,
                      "description": "False selects each input position at most once; true makes independent draws and permits repeated positions.",
                      "type": "boolean"
                    },
                    "target_round": {
                      "default": 0,
                      "description": "0 asks the server to choose the next safe unpublished round; a positive value makes a client_fixed commitment and must still be safely in the future.",
                      "minimum": 0,
                      "type": "integer"
                    }
                  },
                  "required": [
                    "items",
                    "count"
                  ],
                  "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": "Verifiable Random result and complete drand derivation transcript.",
                  "properties": {
                    "algorithm_version": {
                      "description": "Pinned canonicalization, derivation, and sampling algorithm version required to reproduce the result.",
                      "enum": [
                        "drand-hkdf-sha256-v1"
                      ],
                      "type": "string"
                    },
                    "beacon": {
                      "additionalProperties": false,
                      "description": "Locally verified drand Quicknet proof used as the public randomness source.",
                      "properties": {
                        "chain_hash": {
                          "description": "Pinned Quicknet chain hash used to fetch and verify the round.",
                          "enum": [
                            "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971"
                          ],
                          "type": "string"
                        },
                        "network": {
                          "description": "Pinned drand network name.",
                          "enum": [
                            "quicknet"
                          ],
                          "type": "string"
                        },
                        "randomness": {
                          "description": "Lowercase hexadecimal randomness derived from the verified signature.",
                          "pattern": "^[0-9a-f]{64}$",
                          "type": "string"
                        },
                        "round": {
                          "description": "Exact verified Quicknet round used for this result.",
                          "minimum": 1,
                          "type": "integer"
                        },
                        "scheduled_time": {
                          "description": "Scheduled UTC publication time of the selected round.",
                          "format": "date-time",
                          "type": "string"
                        },
                        "scheme": {
                          "description": "Pinned drand signature scheme.",
                          "enum": [
                            "bls-unchained-g1-rfc9380"
                          ],
                          "type": "string"
                        },
                        "signature": {
                          "description": "Lowercase hexadecimal BLS signature verified against the pinned Quicknet public key.",
                          "pattern": "^[0-9a-f]{96}$",
                          "type": "string"
                        }
                      },
                      "required": [
                        "network",
                        "chain_hash",
                        "scheme",
                        "round",
                        "scheduled_time",
                        "randomness",
                        "signature"
                      ],
                      "type": "object"
                    },
                    "example_only": {
                      "description": "True only in compiled catalog/keepalive examples; live paid results are false.",
                      "type": "boolean"
                    },
                    "operation": {
                      "description": "Random operation performed by this route.",
                      "enum": [
                        "pick"
                      ],
                      "type": "string"
                    },
                    "processed_at": {
                      "description": "UTC time when the service accepted the request and committed to the round-selection decision.",
                      "format": "date-time",
                      "type": "string"
                    },
                    "request_hash": {
                      "description": "Lowercase SHA-256 of your canonical request JSON — retain the exact request body so you can re-derive the result offline.",
                      "pattern": "^[0-9a-f]{64}$",
                      "type": "string"
                    },
                    "result": {
                      "additionalProperties": false,
                      "description": "Operation-specific result derived deterministically from the verified beacon and request hash.",
                      "properties": {
                        "items": {
                          "description": "Selected strings in draw order.",
                          "items": {
                            "type": "string"
                          },
                          "type": "array"
                        },
                        "original_indices": {
                          "description": "For each selected value, its zero-based position in the input array.",
                          "items": {
                            "type": "integer"
                          },
                          "type": "array"
                        }
                      },
                      "required": [
                        "items",
                        "original_indices"
                      ],
                      "type": "object"
                    },
                    "selection_mode": {
                      "description": "server_next means the server chose the next safe unpublished round, so you trust its selection chronology; client_fixed means the round is the one you committed to before paying and no other round can be substituted; example_only appears only in catalog examples.",
                      "enum": [
                        "server_next",
                        "client_fixed",
                        "example_only"
                      ],
                      "type": "string"
                    },
                    "target_round": {
                      "description": "Echoes the round actually selected for this result; in server_next mode this is the server-chosen round, not the 0 you sent.",
                      "minimum": 1,
                      "type": "integer"
                    }
                  },
                  "required": [
                    "operation",
                    "algorithm_version",
                    "selection_mode",
                    "target_round",
                    "example_only",
                    "processed_at",
                    "request_hash",
                    "beacon",
                    "result"
                  ],
                  "type": "object"
                },
                "type": {
                  "type": "string"
                }
              },
              "required": [
                "type"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        },
        "tags": [
          "verifiable-random",
          "random-pick",
          "random-selection",
          "sample",
          "drand",
          "fair-selection"
        ]
      }
    }
  },
  "liveness": {
    "reliability": null
  },
  "verified": false,
  "featured": false,
  "provider": {
    "host": "verifiable-random.use.x402atlas.com",
    "manifest_name": "verifiable-random.use.x402atlas.com",
    "source": "cdp-mirror",
    "source_manifest_url": "https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources",
    "submitted_at": "2026-10-14T01:15:01.050Z"
  },
  "exampleResponse": {
    "example": {
      "algorithm_version": "drand-hkdf-sha256-v1",
      "beacon": {
        "chain_hash": "52db9ba70e0cc0f6eaf7803dd07447a1f5477735fd3f661792ba94600c84e971",
        "network": "quicknet",
        "randomness": "string",
        "round": 0,
        "scheduled_time": "2026-01-01T00:00:00Z",
        "scheme": "bls-unchained-g1-rfc9380",
        "signature": "string"
      },
      "example_only": true,
      "operation": "pick",
      "processed_at": "2026-01-01T00:00:00Z",
      "request_hash": "string",
      "result": {
        "items": [
          "string"
        ],
        "original_indices": [
          0
        ]
      },
      "selection_mode": "server_next",
      "target_round": 0
    },
    "type": "string"
  }
}