Copilot CLI becomes default agent harness for JetBrains IDEs on June 15 — local harness deprecated, GitHub consolidates on single agent execution model across surfaces
GitHub made Copilot CLI the default agent harness for Copilot in JetBrains IDEs on June 15, deprecating the prior local harness implementation. The consolidation on CLI as the agent execution layer unifies the agent runtime across IDE surfaces (VS Code, JetBrains, web) and command-line surfaces (Copilot CLI standalone, CI/CD integrations).
The substantive piece is the agent-runtime-consolidation pattern. Through 2025 GitHub maintained separate agent runtime implementations per IDE surface — local harness for JetBrains, separate runtime for VS Code, standalone CLI. The June 15 consolidation moves all JetBrains agent work through the same CLI runtime that powers Copilot CLI and the CI/CD integrations. The operational benefit is feature-parity across surfaces; the architectural benefit is reduced maintenance surface.
The procurement read for H2 2026 developer-tools selection is that GitHub's consolidation around CLI-as-runtime is the right architectural play for an agent-control-plane category. The Copilot Desktop App GA two days after the JetBrains consolidation reflects the same consolidation thesis. GitHub is positioning Copilot as a single agent platform with multiple surfaces, rather than separately-managed products per surface.
Microsoft DevBlogs — GitHub Copilot for JetBrains is moving to Copilot CLI as the default agent harness → · ClickUp — GitHub Copilot Updates and Changelog (2026) →