Add-on, historical placement

Live 402 challenge

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

{
  "hint": {
    "miss": "missing_parameter",
    "usage": "/gauge/history?signal_id=<value>&entity=<value>",
    "preview": "/gauge/sample",
    "missing_params": [
      "signal_id",
      "entity"
    ],
    "example_request": "/gauge/history?signal_id=hydrology.river-level&entity=07010000"
  },
  "error": "Missing required query parameter(s): signal_id, entity. A request you can run right now: GET /gauge/history?signal_id=hydrology.river-level&entity=07010000\nX-PAYMENT header is required",
  "rails": {
    "available": [
      "base",
      "solana"
    ],
    "advertised": [
      "base"
    ],
    "optin_hint": "Send \"X-Payment-Network: solana\" (or ?rails=all) to receive every available rail in accepts.",
    "optin_header": "X-Payment-Network",
    "also_advertised_as": {
      "note": "This same 402 is offered twice: the v1 challenge in this body, and a v2 challenge in the PAYMENT-REQUIRED header. They are the SAME offer - identical price, asset and payTo - not two competing ones. Pay with whichever version your client speaks; you do not need both.",
      "rails": "The v2 challenge lists the Solana rail without an opt-in, while this v1 body does not. That is deliberate, not a discrepancy: a v1 network:\"solana\" entry makes some v1 clients reject the WHOLE accepts array, so v1 advertises it only on request. A v2 client matches on solana:5eykt4Us... and is unaffected.",
      "header": "PAYMENT-REQUIRED",
      "naming": "The v2 challenge uses CAIP-2 network ids (eip155:8453, solana:5eykt4Us...) where this v1 body uses the legacy short names (base, solana). Same chains, different identifier scheme - CDP couples the naming to the version, so it cannot be mixed.",
      "encoding": "base64 JSON",
      "x402_version": 2
    }
  },
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x2d16a243ba9fAcC6AC85519d5efad2149DC4C6c3",
      "amount": "5000",
      "scheme": "exact",
      "network": "base",
      "mimeType": "application/json",
      "resource": "https://aeml-x402.zeabur.app/gauge/history",
      "extensions": {
        "bazaar": {
          "info": {
            "input": {
              "type": "http",
              "method": "GET",
              "queryParams": {
                "entity": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[",
                "signal_id": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
              }
            },
            "output": {
              "type": "json"
            }
          },
          "schema": {
            "$schema": "https://json-schema.org/draft/2020-12/schema",
            "properties": {
              "input": {
                "type": "object",
                "required": [
                  "type",
                  "method",
                  "queryParams"
                ],
                "properties": {
                  "type": {
                    "const": "http"
                  },
                  "method": {
                    "enum": [
                      "GET"
                    ],
                    "type": "string"
                  },
                  "queryParams": {
                    "type": "object",
                    "required": [
                      "signal_id",
                      "entity"
                    ],
                    "properties": {
                      "entity": {
                        "type": "string",
                        "examples": [
                          "07010000"
                        ],
                        "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]"
                      },
                      "signal_id": {
                        "type": "string",
                        "examples": [
                          "hydrology.river-level"
                        ],
                        "description": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
                      }
                    },
                    "additionalProperties": false
                  }
                }
              },
              "output": {
                "type": "object",
                "required": [
                  "type"
                ],
                "properties": {
                  "type": {
                    "const": "json"
                  }
                }
              }
            }
          },
          "priceUsd": "$0.005",
          "discoverable": true,
          "outputSchema": {
            "type": "object",
            "required": [
              "nature",
              "dim",
              "history"
            ],
            "properties": {
              "dim": {
                "type": "string",
                "description": "Always the literal \"history\""
              },
              "grade": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "Honest data-grade disclosure (e.g. \"screening-level, not decision-grade\")"
              },
              "scope": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "Honest statement of scope and limits: monitoring is not forecasting, intelligence is not instruction, and the boundary of what is verifiable"
              },
              "entity": {
                "type": "string",
                "description": "Monitored object id (e.g. btc / us / hormuz); full list at free /gauge/catalog or /gauge/preview"
              },
              "nature": {
                "type": "string",
                "description": "Neutrality statement: GAUGE supplies observations and trend description only - no judgement, no prediction, no recommendation"
              },
              "history": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Seasonal-percentile projection: single-point position + frequency + percentiles + method and source"
              },
              "_citation": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Offline-verifiable citation: {statement_type, not_advice:bool, claim, fact, source, record_hash, signature(Ed25519), key_id, issuer_DID(did:key), verify_url} - the trust root for zero-trust self-verification"
              },
              "signal_id": {
                "type": "string",
                "description": "Signal id in genus.species ASCII binomial form (e.g. crypto.spot / macro.unemployment / shipping.route-disruption); full list at free /gauge/catalog"
              },
              "provenance": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Data lineage: {served_from, data_as_of, oldest_leg_as_of, data_age_hours (frozen age, reference only), age_hours_now (age computed at request time - the real basis for freshness), freshness(fresh|recent|stale), freshness_basis (the cadence and threshold used for this row, as a string), dead_source (optional: upstream frozen or discontinued), data_lineage:[{signal,traceable_to,uncertainty,record_hash,...}], validation_status}. Freshness is cadence-aware, so monthly/quarterly/annual official lines are not misjudged against a 24h rule; the same basis is used by free /gauge/coverage. Buyers can trace back to the official source"
              },
              "entity_name": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "Human-readable name of the object"
              },
              "observed_at": {
                "type": "string",
                "description": "Actual observation time of the data, ISO-8601"
              },
              "record_hash": {
                "type": [
                  "string",
                  "null"
                ],
                "description": "sha256:<64hex> (contract A v3, binds the values plus provenance)"
              },
              "data_age_hours": {
                "type": [
                  "number",
                  "null"
                ],
                "description": "Age frozen at collection time (0 = same hour), for reference only - if a collector stalls this field stops moving. For freshness always use provenance.age_hours_now (computed at request time) and provenance.freshness; the threshold basis is in provenance.freshness_basis"
              },
              "decision_points": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "{count, points:[{tag,current,swappable,how}], note} - decision points you can re-run with a swapped tag (one swapped tag = one call); leave it alone and the original context is the default, at no extra charge"
              },
              "source_agreement_cv": {
                "type": [
                  "number",
                  "null"
                ],
                "description": "Multi-source agreement, coefficient of variation (smaller = closer agreement). Present ONLY when two or more CONFIRMED-INDEPENDENT sources measure the same fact at the same time - see sources[].independent. Same source relayed through two channels does not count as independent, and two different time bases (daily mean vs spot) do not count as agreement. Single-source / unconfirmed independence / not applicable -> null"
              },
              "record_hash_verifiable": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "{mode:offline|via-endpoint, note}"
              }
            },
            "additionalProperties": true,
            "conditionalProperties": {
              "last_fact": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Most recent qualifying fact for this line and entity, attached centrally (may be absent when the line has no qualifying fact yet)"
              },
              "decision_points": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Swappable decision points for this entity, attached centrally: {count, points:[{tag,current,swappable,how}], note}. Present only when the entity has at least one swappable tag in the index, so bundles for entities without one omit it"
              },
              "leg_availability": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Per-leg degradation disclosure: which legs are present, which are degraded and why. Present only when at least one leg is degraded"
              },
              "record_hash_verifiable": {
                "type": [
                  "object",
                  "null"
                ],
                "description": "Whether this response can recompute its own record_hash offline. Present only when the payload carries a top-level record_hash; may be absent on list-shaped deliveries where verifiability is stated per row instead"
              }
            }
          },
          "routeTemplate": "/gauge/history",
          "priceUsdNumber": 0.005
        }
      },
      "description": "Add-on, historical placement: seasonal percentile for the current point, frequency, the percentile table, and the method and source used to compute them. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed. $0.0050 per call.",
      "outputSchema": {
        "input": {
          "type": "http",
          "method": "GET",
          "example": {
            "entity": "07010000",
            "signal_id": "hydrology.river-level"
          },
          "required": [
            "signal_id",
            "entity"
          ],
          "properties": {
            "entity": {
              "type": "string",
              "examples": [
                "07010000"
              ],
              "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]"
            },
            "signal_id": {
              "type": "string",
              "examples": [
                "hydrology.river-level"
              ],
              "description": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
            }
          },
          "queryParams": {
            "entity": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]",
            "signal_id": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
          },
          "discoverable": true,
          "exampleRequest": "/gauge/history?signal_id=hydrology.river-level&entity=07010000"
        },
        "output": {
          "type": "object",
          "required": [
            "nature",
            "dim",
            "history"
          ],
          "properties": {
            "dim": {
              "type": "string",
              "description": "Always the literal \"history\""
            },
            "grade": {
              "type": [
                "string",
                "null"
              ],
              "description": "Honest data-grade disclosure (e.g. \"screening-level, not decision-grade\")"
            },
            "scope": {
              "type": [
                "string",
                "null"
              ],
              "description": "Honest statement of scope and limits: monitoring is not forecasting, intelligence is not instruction, and the boundary of what is verifiable"
            },
            "entity": {
              "type": "string",
              "description": "Monitored object id (e.g. btc / us / hormuz); full list at free /gauge/catalog or /gauge/preview"
            },
            "nature": {
              "type": "string",
              "description": "Neutrality statement: GAUGE supplies observations and trend description only - no judgement, no prediction, no recommendation"
            },
            "history": {
              "type": [
                "object",
                "null"
              ],
              "description": "Seasonal-percentile projection: single-point position + frequency + percentiles + method and source"
            },
            "_citation": {
              "type": [
                "object",
                "null"
              ],
              "description": "Offline-verifiable citation: {statement_type, not_advice:bool, claim, fact, source, record_hash, signature(Ed25519), key_id, issuer_DID(did:key), verify_url} - the trust root for zero-trust self-verification"
            },
            "signal_id": {
              "type": "string",
              "description": "Signal id in genus.species ASCII binomial form (e.g. crypto.spot / macro.unemployment / shipping.route-disruption); full list at free /gauge/catalog"
            },
            "provenance": {
              "type": [
                "object",
                "null"
              ],
              "description": "Data lineage: {served_from, data_as_of, oldest_leg_as_of, data_age_hours (frozen age, reference only), age_hours_now (age computed at request time - the real basis for freshness), freshness(fresh|recent|stale), freshness_basis (the cadence and threshold used for this row, as a string), dead_source (optional: upstream frozen or discontinued), data_lineage:[{signal,traceable_to,uncertainty,record_hash,...}], validation_status}. Freshness is cadence-aware, so monthly/quarterly/annual official lines are not misjudged against a 24h rule; the same basis is used by free /gauge/coverage. Buyers can trace back to the official source"
            },
            "entity_name": {
              "type": [
                "string",
                "null"
              ],
              "description": "Human-readable name of the object"
            },
            "observed_at": {
              "type": "string",
              "description": "Actual observation time of the data, ISO-8601"
            },
            "record_hash": {
              "type": [
                "string",
                "null"
              ],
              "description": "sha256:<64hex> (contract A v3, binds the values plus provenance)"
            },
            "data_age_hours": {
              "type": [
                "number",
                "null"
              ],
              "description": "Age frozen at collection time (0 = same hour), for reference only - if a collector stalls this field stops moving. For freshness always use provenance.age_hours_now (computed at request time) and provenance.freshness; the threshold basis is in provenance.freshness_basis"
            },
            "decision_points": {
              "type": [
                "object",
                "null"
              ],
              "description": "{count, points:[{tag,current,swappable,how}], note} - decision points you can re-run with a swapped tag (one swapped tag = one call); leave it alone and the original context is the default, at no extra charge"
            },
            "source_agreement_cv": {
              "type": [
                "number",
                "null"
              ],
              "description": "Multi-source agreement, coefficient of variation (smaller = closer agreement). Present ONLY when two or more CONFIRMED-INDEPENDENT sources measure the same fact at the same time - see sources[].independent. Same source relayed through two channels does not count as independent, and two different time bases (daily mean vs spot) do not count as agreement. Single-source / unconfirmed independence / not applicable -> null"
            },
            "record_hash_verifiable": {
              "type": [
                "object",
                "null"
              ],
              "description": "{mode:offline|via-endpoint, note}"
            }
          },
          "additionalProperties": true,
          "conditionalProperties": {
            "last_fact": {
              "type": [
                "object",
                "null"
              ],
              "description": "Most recent qualifying fact for this line and entity, attached centrally (may be absent when the line has no qualifying fact yet)"
            },
            "decision_points": {
              "type": [
                "object",
                "null"
              ],
              "description": "Swappable decision points for this entity, attached centrally: {count, points:[{tag,current,swappable,how}], note}. Present only when the entity has at least one swappable tag in the index, so bundles for entities without one omit it"
            },
            "leg_availability": {
              "type": [
                "object",
                "null"
              ],
              "description": "Per-leg degradation disclosure: which legs are present, which are degraded and why. Present only when at least one leg is degraded"
            },
            "record_hash_verifiable": {
              "type": [
                "object",
                "null"
              ],
              "description": "Whether this response can recompute its own record_hash offline. Present only when the payload carries a top-level record_hash; may be absent on list-shaped deliveries where verifiability is stated per row instead"
            }
          }
        }
      },
      "maxAmountRequired": "5000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Accepts

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

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x2d16a243ba9facc6ac85519d5efad2149dc4c6c3",
    "amount": "5000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 30
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "GVJJ7rdGiXr5xaYbRwRbjfaJL7fmwRygFi1H6aGqDveb"
    },
    "payTo": "8qEn3Y3GPXdQ28LHshPa4UYeD8V38Lq9b4jCRirQAY3n",
    "amount": "5000",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "maxTimeoutSeconds": 30
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "example": {
          "entity": "07010000",
          "signal_id": "hydrology.river-level"
        },
        "queryParams": {
          "entity": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[",
          "signal_id": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
        },
        "exampleRequest": "/gauge/history?signal_id=hydrology.river-level&entity=07010000"
      },
      "output": {
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "queryParams"
          ],
          "properties": {
            "type": {
              "const": "http"
            },
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "required": [
                "signal_id",
                "entity"
              ],
              "properties": {
                "entity": {
                  "type": "string",
                  "examples": [
                    "07010000"
                  ],
                  "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]"
                },
                "signal_id": {
                  "type": "string",
                  "examples": [
                    "hydrology.river-level"
                  ],
                  "description": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
                }
              },
              "additionalProperties": false
            }
          }
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "const": "json"
            }
          }
        }
      }
    },
    "routeTemplate": "/gauge/history",
    "outputSchemaRef": "/manifest"
  }
}

Provenance

Seen in the source catalog

2026-08-16 12:49Z

Last indexed by Roundhouse

2026-09-15 12:20Z

Last enriched (probe, favicon, geo)

2026-09-23 22:15Z

x402 version

2

Max timeout

30s

Liveness probe

HTTP 402