numeral_calculate_tax

Calculate sales tax / VAT for an order — a STATELESS quote that persists nothing (record it later with numeral_create_transaction using the returned calculation id). Returns per-jurisdiction rates, total_tax_amount, and totals. Provide a customer address and one or more line items (each needs reference_product_id OR product_category). Amounts are in the currency's smallest unit (cents). Numeral: POST /tax/calculations.

read-only

Argument	Type	Description
customer*	object	Customer details — address is required.
metadata	object	Arbitrary string key/value metadata.
order_details*	object	Order details.
origin_address	object	The address a product ships from. Optional on 2024-09-01; required on API version 2025-05-12+.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "customer",
    "order_details"
  ],
  "properties": {
    "customer": {
      "type": "object",
      "required": [
        "address"
      ],
      "properties": {
        "id": {
          "type": "string",
          "description": "A Numeral customer id (cus_...) for order tracking / exemptions."
        },
        "address": {
          "type": "object",
          "required": [
            "address_line_1",
            "address_city",
            "address_province",
            "address_postal_code",
            "address_country",
            "address_type"
          ],
          "properties": {
            "address_city": {
              "type": "string",
              "description": "City."
            },
            "address_type": {
              "enum": [
                "shipping",
                "billing"
              ],
              "type": "string",
              "description": "Address type: \"shipping\" for physical goods, \"billing\" for software/digital goods."
            },
            "address_line_1": {
              "type": "string",
              "description": "Street address, line 1."
            },
            "address_line_2": {
              "type": "string",
              "description": "Street address, line 2 (optional)."
            },
            "address_country": {
              "type": "string",
              "description": "Country — a valid ISO 3166-1 alpha-2 code (e.g. \"US\")."
            },
            "address_province": {
              "type": "string",
              "description": "State/province/region — a valid 2-letter ISO 3166-2 subdivision code (e.g. \"CA\")."
            },
            "address_postal_code": {
              "type": "string",
              "description": "Postal/ZIP code."
            }
          },
          "description": "Customer address (required)."
        }
      },
      "description": "Customer details — address is required."
    },
    "metadata": {
      "type": "object",
      "description": "Arbitrary string key/value metadata.",
      "propertyNames": {
        "type": "string"
      },
      "additionalProperties": {
        "type": "string"
      }
    },
    "order_details": {
      "type": "object",
      "required": [
        "customer_currency_code",
        "tax_included_in_amount",
        "line_items"
      ],
      "properties": {
        "line_items": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "amount",
              "quantity"
            ],
            "properties": {
              "amount": {
                "type": "number",
                "description": "Line-item price in the currency's SMALLEST unit (e.g. USD 2000 = $20.00). Tax is calculated against this."
              },
              "quantity": {
                "type": "number",
                "description": "Quantity of this product being sold."
              },
              "product_category": {
                "type": "string",
                "description": "A tax category from Numeral's taxonomy, e.g. \"GENERAL_MERCHANDISE\", \"SAAS_GENERAL\" (required if no reference_product_id)."
              },
              "reference_product_id": {
                "type": "string",
                "description": "Your product id (required if no product_category)."
              },
              "reference_line_item_id": {
                "type": "string",
                "description": "Your line-item id (optional; for record keeping)."
              },
              "fallback_product_category": {
                "type": "string",
                "description": "Fallback tax category used when reference_product_id has no matching product in Numeral."
              }
            }
          },
          "minItems": 1,
          "description": "Order line items (one per product type)."
        },
        "customer_currency_code": {
          "type": "string",
          "description": "Currency code. For API version 2024-09-01: \"USD\" or \"CAD\"."
        },
        "tax_included_in_amount": {
          "type": "boolean",
          "description": "Do the line-item amounts already include tax? Typically false for North America."
        }
      },
      "description": "Order details."
    },
    "origin_address": {
      "type": "object",
      "required": [
        "address_line_1",
        "address_city",
        "address_province",
        "address_postal_code",
        "address_country"
      ],
      "properties": {
        "address_city": {
          "type": "string",
          "description": "City."
        },
        "address_line_1": {
          "type": "string",
          "description": "Street address, line 1."
        },
        "address_line_2": {
          "type": "string",
          "description": "Street address, line 2 (optional)."
        },
        "address_country": {
          "type": "string",
          "description": "Country — a valid ISO 3166-1 alpha-2 code (e.g. \"US\")."
        },
        "address_province": {
          "type": "string",
          "description": "State/province/region — a valid 2-letter ISO 3166-2 subdivision code (e.g. \"CA\")."
        },
        "address_postal_code": {
          "type": "string",
          "description": "Postal/ZIP code."
        }
      },
      "description": "The address a product ships from. Optional on 2024-09-01; required on API version 2025-05-12+."
    }
  }
}

numeral_create_customer

CREATES a customer record — this WRITES to your Numeral customer list (used for order tracking and tax exemptions). Numeral: POST /tax/customers.

destructive

Argument	Type	Description
name	string	Customer name.
email*	string	Customer email (required).
is_tax_exempt	boolean	Whether this customer is tax exempt.
reference_customer_id	string	Your own id for this customer (for reference-based lookups).

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "email"
  ],
  "properties": {
    "name": {
      "type": "string",
      "description": "Customer name."
    },
    "email": {
      "type": "string",
      "description": "Customer email (required)."
    },
    "is_tax_exempt": {
      "type": "boolean",
      "description": "Whether this customer is tax exempt."
    },
    "reference_customer_id": {
      "type": "string",
      "description": "Your own id for this customer (for reference-based lookups)."
    }
  }
}

numeral_create_product

CREATES (or upserts) a product with its tax category — this WRITES to your Numeral product catalog, which drives future tax calculations. Numeral: POST /tax/products.

destructive

Argument	Type	Description
product_category*	string	A tax category from Numeral's taxonomy, e.g. "GENERAL_MERCHANDISE", "SAAS_GENERAL".
reference_product_id*	string	Your product id (used to reference this product in calculations).
reference_product_name*	string	Human-readable product name.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "reference_product_id",
    "reference_product_name",
    "product_category"
  ],
  "properties": {
    "product_category": {
      "type": "string",
      "description": "A tax category from Numeral's taxonomy, e.g. \"GENERAL_MERCHANDISE\", \"SAAS_GENERAL\"."
    },
    "reference_product_id": {
      "type": "string",
      "description": "Your product id (used to reference this product in calculations)."
    },
    "reference_product_name": {
      "type": "string",
      "description": "Human-readable product name."
    }
  }
}

numeral_create_refund

RECORDS a refund against a transaction — this WRITES a live tax/compliance record (adjusts tax owed). Use type="full" to refund the whole transaction, or type="partial" with line_items (each keyed by reference_product_id) for a partial refund. Numeral: POST /tax/refunds.

destructive

Argument	Type	Description
type*	string	"full" refunds the whole transaction; "partial" requires line_items.
line_items	array	Required for type="partial": the line items to refund.
transaction_id*	string	The transaction id (tr_...) to refund.
refund_processed_at	number	Unix timestamp (SECONDS) the refund was made. Defaults to now if omitted.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "transaction_id",
    "type"
  ],
  "properties": {
    "type": {
      "enum": [
        "full",
        "partial"
      ],
      "type": "string",
      "description": "\"full\" refunds the whole transaction; \"partial\" requires line_items."
    },
    "line_items": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "reference_product_id"
        ],
        "properties": {
          "reference_product_id": {
            "type": "string",
            "description": "Product id to apply the refund against (matches the original transaction line item)."
          },
          "sales_amount_refunded": {
            "type": "number",
            "description": "Sale amount refunded for this line, in the currency's smallest unit (cents)."
          },
          "reference_line_item_id": {
            "type": "string",
            "description": "Your line-item id (optional; for reporting)."
          }
        }
      },
      "description": "Required for type=\"partial\": the line items to refund."
    },
    "transaction_id": {
      "type": "string",
      "description": "The transaction id (tr_...) to refund."
    },
    "refund_processed_at": {
      "type": "number",
      "description": "Unix timestamp (SECONDS) the refund was made. Defaults to now if omitted."
    }
  }
}

numeral_create_transaction

RECORDS a completed sale as a transaction — this WRITES a live tax/compliance record used for filings. Supply the `calculation_id` returned by numeral_calculate_tax and your `reference_order_id`. Numeral: POST /tax/transactions.

destructive

Argument	Type	Description
metadata	object	Arbitrary string key/value metadata.
calculation_id*	string	The calculation id returned by numeral_calculate_tax.
reference_order_id*	string	Your order id for this sale (used for record keeping / dedupe).
transaction_processed_at	number	Unix timestamp (SECONDS) the sale was processed. Defaults to now if omitted.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "calculation_id",
    "reference_order_id"
  ],
  "properties": {
    "metadata": {
      "type": "object",
      "description": "Arbitrary string key/value metadata.",
      "propertyNames": {
        "type": "string"
      },
      "additionalProperties": {
        "type": "string"
      }
    },
    "calculation_id": {
      "type": "string",
      "description": "The calculation id returned by numeral_calculate_tax."
    },
    "reference_order_id": {
      "type": "string",
      "description": "Your order id for this sale (used for record keeping / dedupe)."
    },
    "transaction_processed_at": {
      "type": "number",
      "description": "Unix timestamp (SECONDS) the sale was processed. Defaults to now if omitted."
    }
  }
}

numeral_get_customer

Get a customer by id. By default `customer_id` is the Numeral id (cus_...); set id_type to "reference" to look up by your own reference_customer_id. Returns name, email, and tax-exempt status. Numeral: GET /tax/customers/{customer_id}.

read-only

Argument	Type	Description
id_type	string	Which id space `customer_id` is in (default: numeral).
customer_id*	string	The customer id — a Numeral id (cus_...) by default, or your reference id when id_type="reference".

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "customer_id"
  ],
  "properties": {
    "id_type": {
      "enum": [
        "numeral",
        "reference"
      ],
      "type": "string",
      "description": "Which id space `customer_id` is in (default: numeral)."
    },
    "customer_id": {
      "type": "string",
      "description": "The customer id — a Numeral id (cus_...) by default, or your reference id when id_type=\"reference\"."
    }
  }
}

numeral_get_product

Get a single product by its reference_product_id (your id). Returns the product's name, product_category, and timestamps. Numeral: GET /tax/products/{reference_product_id}.

read-only

Argument	Type	Description
reference_product_id*	string	Your product id (the reference_product_id used when the product was created).

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "reference_product_id"
  ],
  "properties": {
    "reference_product_id": {
      "type": "string",
      "description": "Your product id (the reference_product_id used when the product was created)."
    }
  }
}

numeral_get_transaction

Get a recorded transaction by its Numeral id (tr_...). Returns the transaction with its line items, currencies, and metadata. Numeral: GET /tax/transactions/{transaction_id}.

read-only

Argument	Type	Description
transaction_id*	string	The Numeral transaction id (tr_...).

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "transaction_id"
  ],
  "properties": {
    "transaction_id": {
      "type": "string",
      "description": "The Numeral transaction id (tr_...)."
    }
  }
}

numeral_list_products

List your Numeral products (up to 50 per page), each with its reference id, name, and product_category. Use `cursor` (the last_product_id from a previous page) to paginate; has_more indicates more pages. Numeral: GET /tax/products.

read-only

Argument	Type	Description
cursor	string	Pagination cursor — pass the last_product_id from the previous page.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "cursor": {
      "type": "string",
      "description": "Pagination cursor — pass the last_product_id from the previous page."
    }
  }
}

numeral_list_transaction_refunds

List all refunds recorded against a transaction. Returns {refunds:[...]}. Numeral: GET /tax/transactions/{transaction_id}/refunds.

read-only

Argument	Type	Description
transaction_id*	string	The Numeral transaction id (tr_...).

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "transaction_id"
  ],
  "properties": {
    "transaction_id": {
      "type": "string",
      "description": "The Numeral transaction id (tr_...)."
    }
  }
}

numeral_ping

Health check — verifies the API key works and reports the environment (test/prod), api_version, and server timestamp. Numeral: GET /tax/ping.

read-only

No arguments.

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {}
}

Numeral MCP by usefulapi

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numeral_calculate_tax

Numeral MCP by usefulapi

Try it

numeral_calculate_tax

Tools (11)