data.spencermcw.com

Which Medicare Part D formularies changed this month? Drugs added or dropped, tier, prior-authorization, step-therapy and quantity-limit changes and plan premium changes, computed by Distill from CMS’s monthly formulary files. Updated monthly. $0.05 per call (x402, USDC on Base); 3 free calls a day.

DataLiveeip155:8453Exactvia cdp
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far.
$0.73
Verified settled volume
28 settlements proven x402 by their on-chain EIP-3009 marker.
$0.050
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-10-22 16:53Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xE6900aE625875b748f56Fb45C3e06a59Be8870DF

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",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xE6900aE625875b748f56Fb45C3e06a59Be8870DF",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://data.spencermcw.com/v1/medicare/partd/changes",
    "mimeType": "application/json",
    "description": "Which Medicare Part D formularies changed this month? Drugs added or dropped, tier, prior-authorization, step-therapy and quantity-limit changes and plan premium changes, computed by Distill from CMS’s monthly formulary files. Updated monthly. $0.05 per call (x402, USDC on Base); 3 free calls a day."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "key": "2723345",
            "limit": 2,
            "entity": "formulary"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "data": {
              "records": [
                {
                  "id": "814",
                  "key": "00026059:2723345",
                  "new": "3",
                  "old": "5",
                  "field": "tier",
                  "entity": "formulary",
                  "released": "2026-09-16",
                  "plan_year": 2026,
                  "detected_at": "2026-10-21T06:36:03.486Z",
                  "method_version": "medicare.partd@1.0.0",
                  "source_sha256_new": "51d0d4177f00458ef420da1491f91f2e4f0a17dc11c253232a9bcc06572d21f2",
                  "source_sha256_old": "37532d0916c7b5f348123e993b8eb8c76f08c97d70c099cb1fc6f6b3cdacb696"
                },
                {
                  "id": "962",
                  "key": "00026063:2723345",
                  "new": "3",
                  "old": "4",
                  "field": "tier",
                  "entity": "formulary",
                  "released": "2026-09-16",
                  "plan_year": 2026,
                  "detected_at": "2026-10-21T06:36:03.486Z",
                  "method_version": "medicare.partd@1.0.0",
                  "source_sha256_new": "51d0d4177f00458ef420da1491f91f2e4f0a17dc11c253232a9bcc06572d21f2",
                  "source_sha256_old": "37532d0916c7b5f348123e993b8eb8c76f08c97d70c099cb1fc6f6b3cdacb696"
                }
              ],
              "next_cursor": "962"
            }
          }
        }
      },
      "schema": {
        "type": "object",
        "$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",
                "properties": {
                  "key": {
                    "type": "string",
                    "pattern": "^[A-Za-z0-9:-]{1,40}$"
                  },
                  "limit": {
                    "type": "integer",
                    "maximum": 100,
                    "minimum": 1
                  },
                  "since": {
                    "type": "string",
                    "format": "date-time",
                    "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
                  },
                  "cursor": {
                    "type": "string",
                    "pattern": "^\\d{1,12}$"
                  },
                  "entity": {
                    "enum": [
                      "formulary",
                      "plan"
                    ],
                    "type": "string"
                  },
                  "plan_year": {
                    "type": "integer",
                    "maximum": 2100,
                    "minimum": 2000
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "properties": {
                  "data": {
                    "type": "object",
                    "required": [
                      "records",
                      "next_cursor"
                    ],
                    "properties": {
                      "records": {
                        "type": "array",
                        "items": {
                          "type": "object",
                          "required": [
                            "id",
                            "plan_year",
                            "released",
                            "entity",
                            "key",
                            "field",
                            "old",
                            "new",
                            "detected_at",
                            "source_sha256_old",
                            "source_sha256_new",
                            "method_version"
                          ],
                          "properties": {
                            "id": {
                              "type": "string"
                            },
                            "key": {
                              "type": "string",
                              "description": "formulary: <formulary id>:<RxCUI>; plan: contract-plan-segment."
                            },
                            "new": {
                              "type": [
                                "string",
                                "null"
                              ]
                            },
                            "old": {
                              "type": [
                                "string",
                                "null"
                              ]
                            },
                            "field": {
                              "type": "string"
                            },
                            "entity": {
                              "enum": [
                                "formulary",
                                "plan"
                              ],
                              "type": "string"
                            },
                            "released": {
                              "type": "string"
                            },
                            "plan_year": {
                              "type": "integer",
                              "maximum": 9007199254740991,
                              "minimum": -9007199254740991
                            },
                            "detected_at": {
                              "type": "string"
                            },
                            "method_version": {
                              "type": "string"
                            },
                            "source_sha256_new": {
                              "type": [
                                "string",
                                "null"
                              ]
                            },
                            "source_sha256_old": {
                              "type": [
                                "string",
                                "null"
                              ]
                            }
                          },
                          "additionalProperties": false
                        }
                      },
                      "next_cursor": {
                        "type": [
                          "string",
                          "null"
                        ]
                      }
                    },
                    "additionalProperties": false
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "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.

0.05USDC≈ $0.05 USD
on Base · exact scheme

Pay 0.05 USDC on Base to 0xE690…870DF. The signed payment is good for 5 minutes.

USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
50000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xE6900aE625875b748f56Fb45C3e06a59Be8870DF",
    "amount": "50000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "key": "2723345",
          "limit": 2,
          "entity": "formulary"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "data": {
            "records": [
              {
                "id": "814",
                "key": "00026059:2723345",
                "new": "3",
                "old": "5",
                "field": "tier",
                "entity": "formulary",
                "released": "2026-09-16",
                "plan_year": 2026,
                "detected_at": "2026-10-21T06:36:03.486Z",
                "method_version": "medicare.partd@1.0.0",
                "source_sha256_new": "51d0d4177f00458ef420da1491f91f2e4f0a17dc11c253232a9bcc06572d21f2",
                "source_sha256_old": "37532d0916c7b5f348123e993b8eb8c76f08c97d70c099cb1fc6f6b3cdacb696"
              },
              {
                "id": "962",
                "key": "00026063:2723345",
                "new": "3",
                "old": "4",
                "field": "tier",
                "entity": "formulary",
                "released": "2026-09-16",
                "plan_year": 2026,
                "detected_at": "2026-10-21T06:36:03.486Z",
                "method_version": "medicare.partd@1.0.0",
                "source_sha256_new": "51d0d4177f00458ef420da1491f91f2e4f0a17dc11c253232a9bcc06572d21f2",
                "source_sha256_old": "37532d0916c7b5f348123e993b8eb8c76f08c97d70c099cb1fc6f6b3cdacb696"
              }
            ],
            "next_cursor": "962"
          }
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "properties": {
                "key": {
                  "type": "string",
                  "pattern": "^[A-Za-z0-9:-]{1,40}$"
                },
                "limit": {
                  "type": "integer",
                  "maximum": 100,
                  "minimum": 1
                },
                "since": {
                  "type": "string",
                  "format": "date-time",
                  "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
                },
                "cursor": {
                  "type": "string",
                  "pattern": "^\\d{1,12}$"
                },
                "entity": {
                  "enum": [
                    "formulary",
                    "plan"
                  ],
                  "type": "string"
                },
                "plan_year": {
                  "type": "integer",
                  "maximum": 2100,
                  "minimum": 2000
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object",
              "properties": {
                "data": {
                  "type": "object",
                  "required": [
                    "records",
                    "next_cursor"
                  ],
                  "properties": {
                    "records": {
                      "type": "array",
                      "items": {
                        "type": "object",
                        "required": [
                          "id",
                          "plan_year",
                          "released",
                          "entity",
                          "key",
                          "field",
                          "old",
                          "new",
                          "detected_at",
                          "source_sha256_old",
                          "source_sha256_new",
                          "method_version"
                        ],
                        "properties": {
                          "id": {
                            "type": "string"
                          },
                          "key": {
                            "type": "string",
                            "description": "formulary: <formulary id>:<RxCUI>; plan: contract-plan-segment."
                          },
                          "new": {
                            "type": [
                              "string",
                              "null"
                            ]
                          },
                          "old": {
                            "type": [
                              "string",
                              "null"
                            ]
                          },
                          "field": {
                            "type": "string"
                          },
                          "entity": {
                            "enum": [
                              "formulary",
                              "plan"
                            ],
                            "type": "string"
                          },
                          "released": {
                            "type": "string"
                          },
                          "plan_year": {
                            "type": "integer",
                            "maximum": 9007199254740991,
                            "minimum": -9007199254740991
                          },
                          "detected_at": {
                            "type": "string"
                          },
                          "method_version": {
                            "type": "string"
                          },
                          "source_sha256_new": {
                            "type": [
                              "string",
                              "null"
                            ]
                          },
                          "source_sha256_old": {
                            "type": [
                              "string",
                              "null"
                            ]
                          }
                        },
                        "additionalProperties": false
                      }
                    },
                    "next_cursor": {
                      "type": [
                        "string",
                        "null"
                      ]
                    }
                  },
                  "additionalProperties": false
                }
              }
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-10-22 16:53Z
Last indexed by Roundhouse
2026-10-26 17:50Z
Last enriched (probe, favicon, geo)
2026-10-22 22:46Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service data.spencermcw.com and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=data.spencermcw.com'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://data.spencermcw.com/v1/medicare/partd/changes, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at
GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at
https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.