use discovery for email request

Author: valhuber

docs/Logic.md

@@ -13,17 +13,18 @@
 ## Rule Types
 The table shows excerpts only; see the ```ApiLogicProject``` (Northwind) sample for full syntax.
 
-| Rule | Summary   | Example | Notes |
-| :------------- | :------------- | :----- | :----- |
-| Constraint     | Boolean function must be True<br>else transaction rolled back | ```row.Balance <= row.CreditLimit```<br><br>```row.Salary >= Decimal('1.20') * old_row.Salary``` | Multi-field<br>```old_row``` |
-| Formula | Function computes column value | ```row.UnitPrice * row.Quantity```<br><br>```row.OrderHeader.ShippedDate``` | lambda, or function<br>Parent ```(OrderHeader)``` references |
-| Sum | Derive parent-attribute as sum of designated child attribute; optional child qualification | ```Rule.sum(derive=Customer.Balance, as_sum_of=Order.AmountTotal,where=lambda row: row.ShippedDate is None)``` | Parent attribute can be hybrid (virtual)<br>scalable: pruning, adjustment |
-| Count | Derive parent-attribute as count of child rows; optional child qualification | ```Rule.count(derive=Order.OrderDetailCount, as_count_of=OrderDetail)``` | counts are useful as child existence checks |
-| Copy      | Child value set from Parent     | ```OrderDetail.ProductPrice = copy(Product.Price)``` | Unlike formula references, parent changes are not propagated<br>e.g, Order totals for Monday are not affected by a Tuesday price increase |
-| Event      | Python Function    | on insert, call ```congratulate_sales_rep``` | See [Extensibility](Logic-Why.md#extend-python) for a information on early, row and commit events |
-| Parent Check      | Ensure Parent row exists | Orders must have a Customer | See [Referential Integrity](https://github.com/valhuber/LogicBank/wiki/Referential-Integrity) |
-| Allocation      | Allocate a provider amount to recipients | allocate a payment to outstanding orders | See [Allocation](https://github.com/valhuber/LogicBank/wiki/Sample-Project---Allocation) for an example |
-| Copy Row      | Create child row by copying parent | audit Employee Salary changes to EmployeeAudit | See [Rule Extensibility](https://github.com/valhuber/LogicBank/wiki/Rule-Extensibility) |
+| Rule            | Summary                                                                                    | Example                                                                                                        | Notes                                                                                                                                     |
+| :-------------- | :----------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------- |
+| Constraint      | Boolean function must be True<br>else transaction rolled back                              | ```row.Balance <= row.CreditLimit```<br><br>```row.Salary >= Decimal('1.20') * old_row.Salary```               | Multi-field<br>```old_row```                                                                                                              |
+| Formula         | Function computes column value                                                             | ```row.UnitPrice * row.Quantity```<br><br>```row.OrderHeader.ShippedDate```                                    | lambda, or function<br>Parent ```(OrderHeader)``` references                                                                              |
+| Sum             | Derive parent-attribute as sum of designated child attribute; optional child qualification | ```Rule.sum(derive=Customer.Balance, as_sum_of=Order.AmountTotal,where=lambda row: row.ShippedDate is None)``` | Parent attribute can be hybrid (virtual)<br>scalable: pruning, adjustment                                                                 |
+| Count           | Derive parent-attribute as count of child rows; optional child qualification               | ```Rule.count(derive=Order.OrderDetailCount, as_count_of=OrderDetail)```                                       | counts are useful as child existence checks                                                                                               |
+| Copy            | Child value set from Parent                                                                | ```OrderDetail.ProductPrice = copy(Product.Price)```                                                           | Unlike formula references, parent changes are not propagated<br>e.g, Order totals for Monday are not affected by a Tuesday price increase |
+| Event           | Python Function                                                                            | on insert, call ```congratulate_sales_rep```                                                                   | See [Extensibility](Logic-Why.md#extend-python) for a information on early, row and commit events                                         |
+| Parent Check    | Ensure Parent row exists                                                                   | Orders must have a Customer                                                                                    | See [Referential Integrity](https://github.com/valhuber/LogicBank/wiki/Referential-Integrity)                                             |
+| Allocation      | Allocate a provider amount to recipients                                                   | allocate a payment to outstanding orders                                                                       | See [Allocation](https://github.com/valhuber/LogicBank/wiki/Sample-Project---Allocation) for an example                                   |
+| Copy Row        | Create child row by copying parent                                                         | audit Employee Salary changes to EmployeeAudit                                                                 | See [Rule Extensibility](https://github.com/valhuber/LogicBank/wiki/Rule-Extensibility)                                                   |
+| Request Pattern | Create Row to run service, per logic                                                       | MCP request: _"find the overdue orders, and send an email offering a discount"_                                | See [MCP Send Mail](Integration-MCP.md#3a-logic-request-pattern)                                                                          |
 
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