# `LLMDB.Pricing`
[🔗](https://github.com/agentjido/llm_db/blob/main/lib/llm_db/pricing.ex#L1)

Pricing pipeline for converting legacy cost data and applying provider defaults.

This module handles two key transformations during snapshot loading:

1. **Legacy cost conversion** - Converts the simple `cost` map (input/output/cache rates)
   into the flexible `pricing.components` format for backward compatibility.

2. **Provider defaults** - Merges provider-level pricing defaults (e.g., tool pricing)
   into each model's pricing, respecting merge strategies.

## Pipeline

The pricing transformations run during `LLMDB.Loader.load/1`:

    models
    |> Pricing.apply_cost_components()      # Convert cost -> pricing.components
    |> Pricing.apply_provider_defaults()    # Merge provider defaults

## Pricing Structure

The `pricing` field on models contains:

    %{
      currency: "USD",
      merge: "merge_by_id",  # or "replace"
      components: [
        %{id: "token.input", kind: "token", unit: "token", per: 1_000_000, rate: 3.0},
        %{id: "tool.web_search", kind: "tool", tool: "web_search", unit: "call", per: 1000, rate: 10.0}
      ]
    }

See the [Pricing and Billing guide](pricing-and-billing.md) for full documentation.

# `apply_cost_components`

```elixir
@spec apply_cost_components([LLMDB.Model.t()]) :: [LLMDB.Model.t()]
```

Converts legacy `cost` fields to `pricing.components` format.

For each model with a `cost` map, generates corresponding pricing components:

| Cost Field | Component ID |
|------------|--------------|
| `input` | `token.input` |
| `output` | `token.output` |
| `cache_read` | `token.cache_read` |
| `cache_write` | `token.cache_write` |
| `reasoning` | `token.reasoning` |

Existing `pricing.components` are preserved and take precedence over
generated components (merged by ID).

## Examples

    iex> models = [%{id: "gpt-4", provider: :openai, cost: %{input: 3.0, output: 15.0}}]
    iex> [model] = LLMDB.Pricing.apply_cost_components(models)
    iex> model.pricing.components
    [
      %{id: "token.input", kind: "token", unit: "token", per: 1_000_000, rate: 3.0},
      %{id: "token.output", kind: "token", unit: "token", per: 1_000_000, rate: 15.0}
    ]

# `apply_provider_defaults`

```elixir
@spec apply_provider_defaults([LLMDB.Provider.t()], [LLMDB.Model.t()]) :: [
  LLMDB.Model.t()
]
```

Applies provider-level pricing defaults to models.

For each model, looks up its provider's `pricing_defaults` and merges them
into the model's `pricing` field. The merge behavior depends on the model's
`pricing.merge` setting:

- `"merge_by_id"` (default) - Provider defaults are merged with model components
  by ID. Model components override matching defaults.
- `"replace"` - Model pricing completely replaces provider defaults.

Models without existing `pricing` inherit the full provider defaults.

## Examples

    iex> providers = [%{id: :openai, pricing_defaults: %{
    ...>   currency: "USD",
    ...>   components: [%{id: "tool.web_search", kind: "tool", rate: 10.0}]
    ...> }}]
    iex> models = [%{id: "gpt-4", provider: :openai, pricing: nil}]
    iex> [model] = LLMDB.Pricing.apply_provider_defaults(providers, models)
    iex> model.pricing.components
    [%{id: "tool.web_search", kind: "tool", rate: 10.0}]

---

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