> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.nozle.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Cost Model

Create a new cost model for margin calculations.

**Auth:** `sk_` only

<Warning>
  All cost model endpoints require a secret key (`sk_`). Publishable keys will receive a 403 Forbidden response.
</Warning>

<ParamField body="name" type="string" required>
  Human-readable name for the cost model (e.g. "GPT-4 API Cost")
</ParamField>

<ParamField body="metric_code" type="string" required>
  Billable metric code this cost model applies to
</ParamField>

<ParamField body="cost_per_unit_cents" type="number" required>
  Cost per unit in cents
</ParamField>

<ParamField body="model" type="string">
  AI model identifier (e.g. `gpt-4`, `claude-sonnet-4-20250514`)
</ParamField>