Takes two state documents — target (what the twin should look like) and observed

Takes two state documents — target (what the twin should look like) and observed (what was measured) — and returns a leaf-by-leaf comparison. Every leaf path carries one of five states: in_tolerance, out_of_tolerance, missing_in_observed, unexpected_in_observed or type_mismatch.

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Endpoint

POST https://agent.halowerk.com/v1/twin-diff

Our checks, last 30 days

Example input (from the provider)

{
  "body": {
    "default_tolerance_ratio": 0,
    "observed": {
      "firmware": "2.3.9",
      "pump": {
        "pressure_bar": 4.15,
        "running": true
      },
      "site": {
        "radius_km": 12.4
      }
    },
    "target": {
      "firmware": "2.4.1",
      "pump": {
        "pressure_bar": 4,
        "running": true
      },
      "site": {
        "radius_km": 12
      }
    },
    "tolerances": [
      {
        "field": "/pump/pressure_bar",
        "tolerance_abs": 0.2,
        "unit": "bar"
      },
      {
        "field": "/site/radius_km",
        "tolerance_ratio": 0.01,
        "unit": "km"
      }
    ]
  },
  "bodyType": "json",
  "method": "POST",
  "type": "http"
}

Promised output schema (from the provider)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "additionalProperties": false,
          "properties": {
            "case_insensitive_strings": {
              "default": false,
              "description": "Compare string leaves without regard to case.",
              "type": "boolean"
            },
            "default_tolerance_ratio": {
              "default": 0,
              "description": "Relative tolerance for numeric paths without their own entry. 0 means exact equality.",
              "maximum": 1,
              "minimum": 0,
              "type": "number"
            },
            "ignore_fields": {
              "description": "Paths to leave out of the comparison. A trailing /* ignores everything below that prefix.",
              "items": {
                "maxLength": 400,
                "minLength": 1,
                "type": "string"
              },
              "maxItems": 200,
              "type": "array"
            },
            "max_fields": {
              "default": 2000,
              "description": "Reject the request if the two documents together hold more leaf paths than this.",
              "maximum": 2000,
              "minimum": 1,
              "type": "integer"
            },
            "observed": {
              "description": "The observed state document (the measurement).",
              "type": "object"
            },
            "target": {
              "description": "The desired state document (the twin).",
              "type": "object"
            },
            "tolerances": {
              "description": "Per-path tolerances. Give tolerance_abs or tolerance_ratio, not both.",
              "items": {
                "additionalProperties": false,
                "properties": {
                  "field": {
                    "description": "Leaf path as it appears in the result, e.g. /pump/pressure_bar. A trailing /* applies the entry to every leaf below that prefix.",
                    "maxLength": 400,
                    "minLength": 1,
                    "type": "string"
                  },
                  "tolerance_abs": {
                    "description": "Absolute tolerance in the unit of this field.",
                    "minimum": 0,
                    "type": "number"
                  },
                  "tolerance_ratio": {
                    "description": "Relative tolerance as a ratio of the larger of the two values.",
                    "maximum": 1,
                    "minimum": 0,
                    "type": "number"
                  },
                  "unit": {
                    "description": "Unit of this field, echoed into the result. Declared by you, never inferred.",
                    "maxLength": 32,
                    "type": "string"
                  }
                },
                "required": [
                  "field"
                ],
                "type": "object"
              },
              "maxItems": 200,
              "type": "array"
            }
          },
          "required": [
            "target",
            "observed"
          ],
          "type": "object"
        },
        "bodyType": {
          "enum": [
            "json",
            "form-data",
            "text"
          ],
          "type": "string"
        },
        "method": {
          "enum": [
            "POST",
            "PUT",
            "PATCH"
          ],
          "type": "string"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method",
        "bodyType",
        "body"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}

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