Chase invoices waiting for approval

# Supplier invoices waiting for approval

## What this skill covers — and what it doesn't

The `get_invoices*` tools read **supplier invoices** (before and after approval). They are the right tools for "which invoices are waiting for approval" — `get_requests` only covers card requests, and `get_payables` only holds an invoice once it is approved.

The MCP **cannot approve or reject** an invoice: no tool does that. This skill produces the list and the chaser draft; approval stays in Spendesk.

## Step 1 — Volume and amounts (no paging)

```json
{ "tool": "get_invoices_summary", "params": { "approvalStatus": ["pending"] } }
```

Returns `count` and `totalsByCurrency` (one block per currency).

⚠️ Three traps verified live:
- `amountDue` is **always 0** in the summary (not computed yet) — never present it as an outstanding balance.
- `netAmount` is a lower bound: invoices with no captured net amount count as 0. Do not derive tax from it.
- Amounts are never added across currencies: present one total per currency.

## Step 2 — List, oldest first

```json
{ "tool": "get_invoices", "params": { "approvalStatus": ["pending"], "sortBy": "createdAt", "sort": "asc", "pageSize": 100 } }
```

Useful fields: `invoiceNumber`, `supplier.name`, `grossAmount.formatted`, `dueDate`, `createdAt`, `purchaseOrders`.

- If `hasNextPage` is `true`, pass `meta.pagination.cursor` back as `cursor`.
- With no `type` filter, only invoices are listed; credit notes need a separate call with `type: "creditNote"`.
- Draft and incomplete invoices are never listed, not even under `pending`.
- `grossAmount` can be `null` on a pending invoice with no captured amount: `null` is not zero.

## Step 3 — Who has to approve

The list does not carry the approval chain. For each invoice to chase:

```json
{ "tool": "get_invoice_by_id", "params": { "id": "<invoice id>" } }
```

Read `approval.steps`: the step whose `state` is `current` holds the expected `approvers`. These are raw `userId` values — resolve them in one call:

```json
{ "tool": "get_users", "params": { "ids": ["<userId1>", "<userId2>"] } }
```

Never show a bare ID. If an ID does not resolve (a former member of the entity), say so. The invoice's `buyer` field also gives the requester, with their name.

## Recommended output format

```
Invoices waiting for approval — <today's date>
Total: N invoices — X EUR · Y USD (per currency, never added together)

| Invoice | Supplier | Amount | Due date | Received on | Expected approver(s) |
```

Flag first the invoices whose due date has already passed: they are late before even being approved.

## Observed result (demo account)

2 invoices pending: 1 in EUR (2,616.00) and 1 in USD (19,513.20). On the USD invoice, the current step expected two approvers, resolved with `get_users`. Both invoices were past their due date and had no linked purchase order.

## Example user prompts

- "Which supplier invoices are waiting for approval, and with whom?"
- "Draft a chaser for the approvers of invoices pending for more than 7 days"
- "How many invoices are stuck in approval, by currency?"