# Copilot Usage API Updates Add BYOK and Custom Models

URL: https://3ammarketer.com/news/copilot-usage-api-updates-byok-custom-models
Published: 2026-11-04

> GitHub has updated the Copilot usage metrics API to differentiate Bring Your Own Key usage and enterprise custom model activity across reports.

The GitHub Copilot usage metrics API now reports bring your own key (BYOK) activity alongside enterprise custom model calls, separating them from standard Copilot-hosted model usage in enterprise and organization reports. The schema update exposes these dimensions at both the individual user and aggregate level across 1-day and 28-day reports. [1][2]

## Tracking local BYOK activity across CLI and apps

The API introduces used_local_byok, a boolean indicating whether a user made at least one local BYOK request in Copilot CLI or the Copilot app that day. Detailed volumes arrive in the totals_by_local_byok object, which provides session counts alongside request, prompt, and token metrics. [1]

To support granular accounting, local BYOK metrics break down across two specific dimensions: byok_kind and surface. The API groups these records into defined categories: [1]

- byok_kind values: local_managed, local_user, local_auto, or remote_user.
- surface values: copilot_cli or copilot_app. [1]

For seat and adoption monitoring, the schema introduces three separate active-user fields: [1]

- daily_active_local_byok_users for distinct users active that day
- weekly_active_local_byok_users for the calendar week
- monthly_active_local_byok_users for the calendar month [1]

## Differentiating enterprise custom models server-side

Deployments using custom-configured endpoints now carry distinct identifiers in consumption data. GitHub added is_custom_enterprise_model as a boolean field on each totals_by_client[].totals_by_model[] entry. The value returns true whenever a request targets a custom model configured specifically for your enterprise or organization. [1]

When a single model serves both as a standard Copilot-hosted model and as a custom enterprise model, the API outputs two separate entries so the counts stay separate. Because GitHub observes enterprise custom model requests server-side, tracking covers every client, including IDEs. [1]

## Telemetry limits and administrative prerequisites

A key operational distinction lies between server-side custom models and client-side BYOK telemetry. While enterprise custom model counts are recorded on the server without client dependencies, local BYOK fields rely strictly on client telemetry. If a developer disables client telemetry, local BYOK requests will undercount. [1]

Access to the updated metrics requires that the Copilot usage metrics policy is enabled. The endpoints are restricted to enterprise owners, organization owners, enterprise billing managers, or roles granting the View Copilot Metrics permission. Report days before the release on November 3, 2026, do not include the is_custom_enterprise_model field. [1][2][3]

![A screenshot of the documentation for the GitHub Copilot usage metrics REST API.](https://dygolixznokmekyvajbb.supabase.co/storage/v1/object/public/images/content/2f1deb2f0995f468d79bad9f.png)

Our read: Treat totals_by_local_byok as a baseline minimum rather than a definitive ceiling for BYOK billing reconciliation, because client telemetry opt-outs cause undercounting. For custom model workloads, rely on the server-side is_custom_enterprise_model flag for audit logs.

Limit: The release notes specify no backfill for reports prior to the release date, and local BYOK metrics undercount whenever client telemetry is disabled.

## Sources

1. [BYOK and enterprise custom models in the Copilot usage API - GitHub Changelog](https://github.blog/changelog/2026-11-03-byok-and-enterprise-custom-models-in-the-copilot-usage-api)
2. [REST API endpoints for Copilot usage metrics - GitHub Docs](https://docs.github.com/en/rest/copilot/copilot-usage)
3. [The latest developer news & insights - The GitHub Blog](https://github.blog/news-insights)