# `Beancount.Directives.Posting`
[🔗](https://github.com/thanos/beancount_ex/blob/v0.6.0/lib/beancount/directives/posting.ex#L1)

A single posting (leg) of a `Beancount.Directives.Transaction`.

See [Costs and Prices](https://beancount.github.io/docs/beancount_language_syntax/#costs-and-prices)
in the Beancount syntax guide.

## Beancount syntax

    Assets:ETrade:IVV   -10 IVV {183.07 USD} @ 197.90 USD
      trade-id: "T-991"

    Expenses:Restaurant

A posting may elide amount and currency; Beancount infers them when balancing.

## Elixir struct

    %Beancount.Directives.Posting{
      account: "Assets:ETrade:IVV",
      amount: Decimal.new("-10"),
      currency: "IVV",
      cost: %Beancount.CostSpec{
        per_amount: Decimal.new("183.07"),
        per_currency: "USD",
        total_amount: nil,
        total_currency: nil,
        date: nil,
        label: nil,
        merge: false
      },
      price: %{amount: Decimal.new("197.90"), currency: "USD", type: :unit},
      flag: nil,
      metadata: %{"trade-id" => "T-991"}
    }

Elided amount (inferred by Beancount):

    %Beancount.Directives.Posting{
      account: "Expenses:Restaurant",
      amount: nil,
      currency: nil,
      cost: nil,
      price: nil,
      flag: nil,
      metadata: %{}
    }

Or use `Beancount.posting/4`:

    Beancount.posting("Assets:ETrade:IVV", Decimal.new("-10"), "IVV",
      cost: %{amount: Decimal.new("183.07"), currency: "USD"},
      price: %{amount: Decimal.new("197.90"), currency: "USD", type: :unit},
      metadata: %{"trade-id" => "T-991"}
    )

## Fields

  * `account` - colon-separated account receiving the posting.
  * `amount` - `Decimal.t()` units posted, or `nil` to elide (Beancount
    interpolates the balancing amount).
  * `currency` - commodity symbol for `amount`, or `nil` when elided.
  * `cost` - `Beancount.CostSpec` (or legacy `%{amount:, currency:}` map)
    for inventory held at cost, e.g. `{183.07 USD}`. `nil` for simple amounts.
  * `price` - unit price `%{amount:, currency:, type: :unit}` (`@ 1.2 USD`)
    or total price `type: :total` (`@@ 120 USD`). `nil` when absent.
  * `flag` - optional per-posting flag (`"!"`, etc.) rendered before the
    account name.
  * `metadata` - optional map rendered as indented lines under the posting.

# `cost`

```elixir
@type cost() :: Beancount.CostSpec.t() | map() | nil
```

A cost specification. See `Beancount.CostSpec`.

# `price`

```elixir
@type price() ::
  %{amount: Decimal.t(), currency: String.t(), type: :unit | :total} | nil
```

A price annotation, e.g. `@ 1.2 USD` or `@@ 120 USD`.

# `t`

```elixir
@type t() :: %Beancount.Directives.Posting{
  account: String.t(),
  amount: Decimal.t() | nil,
  cost: cost(),
  currency: String.t() | nil,
  flag: String.t() | nil,
  metadata: map(),
  price: price()
}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*