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

# Estimate Eval Run

> Preview the size and cost of a run before starting it.

### Headers

<ParamField header="authorization" type="string" required>
  Your API key for authentication.
</ParamField>

### Body Parameters

Accepts the same body as [Create Eval Run](/api-v1/post/evals-runs). Key fields:

<ParamField body="call_ids" type="array of string" required>
  The call IDs to include in the estimate. Between 1 and 5000 calls.
</ParamField>

<ParamField body="attached_agents" type="array of objects">
  The eval agents to score with. Required when `workbench_setup_version_id` is not provided.
</ParamField>

<ParamField body="workbench_setup_version_id" type="string">
  Pinned workbench setup version whose agent roster supplies the agents. Required when `attached_agents` is not provided. Must be provided together with `workbench_setup_id`.
</ParamField>

### Response

<ResponseField name="resolved_atom_count" type="integer">
  Number of call-by-agent evaluations the run will perform.
</ResponseField>

<ResponseField name="estimated_input_tokens" type="integer">
  Estimated number of input tokens consumed by judge calls.
</ResponseField>

<ResponseField name="estimated_output_tokens" type="integer">
  Estimated number of output tokens produced by judge calls.
</ResponseField>

<ResponseField name="estimated_cost_usd_cents" type="number">
  Estimated billable cost in USD cents.
</ResponseField>

<ResponseExample>
  ```json Response theme={null}
  {
    "data": {
      "resolved_atom_count": 150,
      "estimated_input_tokens": 420000,
      "estimated_output_tokens": 15000,
      "estimated_cost_usd_cents": 87.5
    },
    "errors": null
  }
  ```
</ResponseExample>