# GET /api/v1/metrics/usage

Auth: Bearer

HTML: https://cooperemail.com/docs/reference/metrics-usage

## Summary

Current inbox_count, message_count, thread_count, and storage_bytes. storage_bytes is the UTF-8 byte length of text plus html, plus attachment size_bytes. It is not the message body. Passing inbox_id, or calling with an inbox-scoped key, omits domain_count and workspace_count. An account-wide key also receives those two counts for this account only. A sub-account does not see the parent account or a sibling sub-account. Another account's inbox is 404 inbox_not_found. A key without message_read is 403 permission_denied. MCP: cooper_get_metrics with kind usage.

## Query

```json
?inbox_id=inb_…
```

## Response

HTTP 200. Sample values illustrate the schema.

```json
{
  "inbox_count": 1,
  "message_count": 1,
  "thread_count": 1,
  "storage_bytes": 1
}
```

## Errors

- HTTP 404 inbox_not_found
- HTTP 403 permission_denied

The live `message` is the sentence for that code. Branch on `code`.

```json
{
  "error": {
    "type": "not_found",
    "code": "inbox_not_found",
    "docs_url": "https://cooperemail.com/docs#inbox_not_found"
  }
}
```

## Idempotency

This route does not document Idempotency-Key or client_id.