addrbookFor publishers
← The evidence ledger

Evidence row 120260

Observed , by baseline/1.

Kind
listing
About
source_record x402_bazaar:https://saylorinnovations.com/api/kb/python-lru-cache-pitfalls-unhashable-arguments-methods-memory-stale-data
Recorded
Previous row
None: the first of its kind about this subject
Body SHA-256
8ea03fccd8768342210fdf0508c4a68e29706e1caed9d7d7563ed33163cee44e
Leaf
0xcb0ecd1a17752a11a1a95388305f381c7a14ce6a0adeb7c7e0e4169c3017d6fa

What was observed

{
  "endpoints": [
    [
      "x402",
      "https://saylorinnovations.com/api/kb/python-lru-cache-pitfalls-unhashable-arguments-methods-memory-stale-data"
    ]
  ],
  "name": "Saylor Innovations Guide Library",
  "owner_address": "0xa2a8df0f7caabea4e120a2568118f141569fc8aa",
  "raw": {
    "accepts": [
      {
        "amount": "10000",
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "assetTransferMethod": "eip3009",
          "facilitatorOnly": true,
          "memo": "saylor:python-lru-cache-pitfalls",
          "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"
        },
        "maxTimeoutSeconds": 120,
        "network": "eip155:8453",
        "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
        "scheme": "exact"
      },
      {
        "amount": "10000",
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "assetTransferMethod": "eip3009",
          "facilitatorOnly": true,
          "memo": "saylor:python-lru-cache-pitfalls",
          "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"
        },
        "maxTimeoutSeconds": 120,
        "network": "eip155:137",
        "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
        "scheme": "exact"
      },
      {
        "amount": "10000",
        "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
        "extra": {
          "assetTransferMethod": "eip3009",
          "facilitatorOnly": true,
          "memo": "saylor:python-lru-cache-pitfalls",
          "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"
        },
        "maxTimeoutSeconds": 120,
        "network": "eip155:42161",
        "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
        "scheme": "exact"
      },
      {
        "amount": "10000",
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "Hc3sdEAsCGQcpgfivywog9uwtk8gUBUZgsxdME1EJy88",
          "memo": "saylor:python-lru-cache-pitfalls",
          "reference": "74yV9KSeFXLY3CpUQSPyzeDgaZoYeFBaatdq5YK9FUxA",
          "session": "eyJhcnRpY2xlSWQiOiJweXRob24tbHJ1LWNhY2hlLXBpdGZhbGxzLXVuaGFzaGFibGUtYXJndW1lbnRzLW1ldGhvZHMtbWVtb3J5LXN0YWxlLWRhdGEiLCJyZWZlcmVuY2UiOiI3NHlWOUtTZUZYTFkzQ3BVUVNQeXplRGdhWm9ZZUZCYWF0ZHE1WUs5RlV4QSIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6IkVQakZXZGQ1QXVmcVNTcWVNMnFOMXh6eWJhcEM4RzR3RUdHa1p3eVREdDF2IiwibWluQW1vdW50IjoxMDAwMCwiZXhwIjoxNzkyNTAxMDA5MTE3fQ.08gXMuhf-ka7rFaoAp72o4_-JpVmKLBdhPvph94VpPI"
        },
        "maxTimeoutSeconds": 120,
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
        "scheme": "exact"
      },
      {
        "amount": "10000",
        "asset": "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB",
        "extra": {
          "feePayer": "Hc3sdEAsCGQcpgfivywog9uwtk8gUBUZgsxdME1EJy88",
          "memo": "saylor:python-lru-cache-pitfalls",
          "reference": "5f8uK8n3fszrCbnDnhwLCadG7TxUbaQ6cXkFyYrSj6kU",
          "session": "eyJhcnRpY2xlSWQiOiJweXRob24tbHJ1LWNhY2hlLXBpdGZhbGxzLXVuaGFzaGFibGUtYXJndW1lbnRzLW1ldGhvZHMtbWVtb3J5LXN0YWxlLWRhdGEiLCJyZWZlcmVuY2UiOiI1Zjh1SzhuM2ZzenJDYm5Ebmh3TENhZEc3VHhVYmFRNmNYa0Z5WXJTajZrVSIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6IkVzOXZNRnJ6YUNFUm1KZnJGNEgyRllENEtDb05rWTExTWNDZThCZW53TllCIiwibWluQW1vdW50IjoxMDAwMCwiZXhwIjoxNzkyNTAxMDA5MTE3fQ.BGOOpBYGW95hnopUCZqLMD62d5gzA98EQ28DEn67g6g"
        },
        "maxTimeoutSeconds": 120,
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
        "scheme": "exact"
      },
      {
        "amount": "92830",
        "asset": "So11111111111111111111111111111111111111112",
        "extra": {
          "memo": "saylor:python-lru-cache-pitfalls",
          "native": true,
          "note": "Native SOL: send lamports with a system transfer, not an SPL transfer. Price is quoted live and this quote expires in 120s.",
          "quotedLamports": "95702",
          "reference": "AZdwNkYquGn1zU8hw77pAKSGsiwACqkJWEG5WfDGkqE1",
          "session": "eyJhcnRpY2xlSWQiOiJweXRob24tbHJ1LWNhY2hlLXBpdGZhbGxzLXVuaGFzaGFibGUtYXJndW1lbnRzLW1ldGhvZHMtbWVtb3J5LXN0YWxlLWRhdGEiLCJyZWZlcmVuY2UiOiJBWmR3TmtZcXVHbjF6VThodzc3cEFLU0dzaXdBQ3FrSldFRzVXZkRHa3FFMSIsInJlY2lwaWVudCI6IjdMU2pmckpmOGZOc0I4VkE5dTdOM1dFbjI1c21RTHBvYjNTdnlVdlhhY3k3IiwibWludCI6bnVsbCwibWluQW1vdW50Ijo5MjgzMCwiZXhwIjoxNzkyNTAxMDA5MTE3fQ.Fv8UeMOlZKlyhHhj8NmhGUGMMiLhawQ3q1d6yrZBs9w",
          "solUsdPrice": 104.49
        },
        "maxTimeoutSeconds": 120,
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
        "scheme": "exact"
      }
    ],
    "description": "Python lru_cache pitfalls - eviction demo, unhashable list TypeError, methods keep instances alive, stale values, shared mutable results",
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "method": "GET",
            "type": "http"
          },
          "output": {
            "example": {
              "body": "Executed on Python 3.10: eviction with maxsize 2, cache_info counts, TypeError unhashable type list, an instance still alive after del because of a method cache, cached_property computing once, stale time values until cache_clear and a shared mutable result.",
              "c": "Self-Hosting & Infra",
              "id": "python-lru-cache-pitfalls-unhashable-arguments-methods-memory-stale-data",
              "t": "functools.lru_cache Pitfalls: Unhashable Arguments, Methods Keeping Objects Alive, Stale Results and Shared Mutables"
            },
            "type": "json"
          }
        },
        "schema": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "properties": {
            "input": {
              "additionalProperties": false,
              "properties": {
                "method": {
                  "enum": [
                    "GET"
                  ],
                  "type": "string"
                },
                "type": {
                  "const": "http",
                  "type": "string"
                }
              },
              "required": [
                "type",
                "method"
              ],
              "type": "object"
            },
            "output": {
              "properties": {
                "example": {
                  "properties": {
                    "body": {
                      "description": "Main body text",
                      "type": "string"
                    },
                    "c": {
                      "description": "Category of the guide",
                      "type": "string"
                    },
                    "id": {
                      "description": "Identifier of the record",
                      "type": "string"
                    },
                    "license": {
                      "description": "License identifier",
                      "type": "string"
                    },
                    "price": {
                      "description": "Price",
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "t": {
                      "description": "Title of the guide",
                      "type": "string"
                    }
                  },
                  "required": [
                    "id",
                    "t",
                    "c",
                    "body"
                  ],
                  "type": "object"
                },
                "type": {
                  "const": "json",
                  "type": "string"
                }
              },
              "required": [
                "type"
              ],
              "type": "object"
            }
          },
          "required": [
            "input"
          ],
          "type": "object"
        }
      }
    },
    "iconUrl": "https://res.cloudinary.com/bdb-prod/image/upload/c_fill,ar_1:1,w_256,h_256,f_auto,q_auto/v1791811517/bazaar-icons/bc5e2b3d111ebbef.jpg",
    "lastUpdated": "2026-10-20T12:54:49.166Z",
    "quality": {
      "l30DaysTotalCalls": 1,
      "l30DaysUniquePayers": 1,
      "lastCalledAt": "2026-10-20T12:54:48.997Z"
    },
    "resource": "https://saylorinnovations.com/api/kb/python-lru-cache-pitfalls-unhashable-arguments-methods-memory-stale-data",
    "serviceName": "Saylor Innovations Guide Library",
    "tags": [
      "python",
      "functools",
      "lru-cache",
      "caching",
      "memory"
    ],
    "type": "http",
    "x402Version": 2
  },
  "source": "x402_bazaar",
  "summary": "Python lru_cache pitfalls - eviction demo, unhashable list TypeError, methods keep instances alive, stale values, shared mutable results"
}

What the leaf hashes

{"body":"8ea03fccd8768342210fdf0508c4a68e29706e1caed9d7d7563ed33163cee44e","id":120260,"kind":"listing","method":"baseline/1","observed_us":1793025617557405,"prev":null,"subject":"x402_bazaar:https://saylorinnovations.com/api/kb/python-lru-cache-pitfalls-unhashable-arguments-methods-memory-stale-data","subject_kind":"source_record"}

Proof

Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of (296695 rows).

  1. 0xcb0ec98784e8bfa352727ed6c407e148ee791d2484c67b055d79e01edf580a76
  2. 0xb936d650ed4ec402bac3bb74849314217b02fab45b05365967648d422f4176cb
  3. 0x4c40ef05bea89249b6c5e4d4f9fc707a84a39d0d00d3808f76dd0cd4b605ea82
  4. 0xb5b1396da0c6351d9bbdcf19050065a0c65c012dc26b55d9557e1434c26ece9f
  5. 0xd0a8b6f11a56002d51854b2dfda96c683f256004ccd287edfaa92cce56865ba3
  6. 0x381fc2d9878848a45a2659bd2940e411134e8e2c25b48a71c81239d2ccea09bb
  7. 0xf764cfb0fe3893160e38114baa165db89cbaef5a79c55129c41ab1b01fddb978
  8. 0xb6bace605fd360da2c6c73e5667ed2942f4d76802a25f3b3c9e09090cdf8bed2
  9. 0x00fbcc59345b153dcb2b8f8346c33167365a33678310565bab22cd4cf59deac1
  10. 0x9789df0b68a0c56f96db447ac03549df4b97c545b493a676ef441af41eab593b
  11. 0xd854065b5246baf332a9ace158b6f99219183612c97d95e881ab7a7e7fb3bd6b
  12. 0x02a11c0460d1a42b6246e1c715f0c3098d82c39154a56e918e2c22b56ca2c978
  13. 0x985acd37cc044d5aa6ad959194da8e91c81045df83517891ed92f1763a9ab825
  14. 0x5b20d8aab05225a3497eadcce89d2e2a586a510fb31334793d3f46f88f0157c5
  15. 0xe94ca5b798e9899ad611e57835af42266e20f53f44977e487d81365e30972beb
  16. 0x703f95866af09c5e5d6ead7411e9a10f964a41a2aff64d4a55ff0053c023a023
  17. 0xd0651cb9bc8155eb52b5247d506e74b8a935057dc190ba52091702ac25ed3a40
  18. 0x9a9024edb5069d88a324facb310a5ce8e495214bbaa968f077bede437390194f
  19. 0x9b9ce5b74b9bab5121612ef6b64920a8d453cbf311096a423eef9702747e868a
Day root
0xf43e8dcc3d451a4788b26be904c55e8c4c0fa75c9666796c51db38d37e2c0df8
Chained
0x702d5ac508f08b0d1accf36af25822d8e5660367494edd17a642fb61e158a57a
Published
On Arc Testnet, block 69251483: 0x495162f8936e19f0039918feebe6c307f327cd6bf8c37219620b1970041fa9ae

How to check it · This row as JSON