Appendix: Unified agent architecture (v1.107+)

tech
github-copilot
prompt-engineering
agents
Appendix covering Agent HQ, execution contexts (local, background, cloud), work tree isolation, session management, and cross-platform agent features introduced in VS Code 1.107+
Author

Dario Airoldi

Published

March 7, 2026

Appendix: Unified Agent Architecture (v1.107+)

Parent article: How to structure content for GitHub Copilot agent files

Related concept: Chat modes, Agent HQ, and execution contexts

VS Code 1.107 introduced a paradigm shift in how agents execute, providing a unified interface for managing agent sessions across multiple execution contexts.

Agent HQ Interface

Agent HQ is the centralized interface for managing all agent sessions:

Feature Functionality
Recent Sessions List Displays local, background, and cloud sessions with unified status
Read/Unread Markers Blue dots indicate unread completed sessions
Filtering & Search Filter by session type, search across session history
Archive Capability Move completed sessions to archive for cleaner workspace
Expand to Sidebar Full sidebar view for detailed session management

Execution Context Details

Local Agents

  • Execute in the current VS Code session
  • Interactive—user can observe and intervene in real-time
  • No isolation—changes affect workspace directly
  • Best for: Quick tasks, iterative refinement, learning agent behavior

Background Agents

  • Execute autonomously without blocking VS Code
  • Use Git work trees for complete filesystem isolation
  • Sessions continue even when VS Code loses focus
  • Changes reviewed and merged after completion
  • Best for: Long-running tasks, parallel work on multiple features

Work Tree Workflow:

  1. Create background agent session (dropdown option to use work tree)
  2. Agent works in isolated work tree—no conflicts with local changes
  3. Work tree appears in Source Control view
  4. Review changes after completion
  5. Use “Apply” action to integrate changes into main workspace

Cloud Agents

  • Execute on GitHub infrastructure
  • Automatically create branch and pull request
  • Fully asynchronous—can close VS Code entirely
  • Best for: Large changes, team collaboration, code review workflows

Delegation Flow

The unified architecture enables seamless delegation between execution contexts:

Planning Mode → Local Agent → Background Agent → Cloud Agent
      ↓              ↓              ↓               ↓
   Creates      Implements     Isolates via      Creates
    Plan         Locally      Work Trees     Branch + PR

“Continue In” options available from:

  • Chat view “Continue in” button
  • Planning mode delegation dropdown
  • Untitled prompt file button

Claude Skills Support

VS Code 1.107 added Claude Skills support, enabling agents to leverage the growing Claude skills ecosystem for extended capabilities. This allows custom agents to access specialized tools and behaviors defined in Claude skill files.

Impact on Agent Design

When designing custom agents, consider the execution context:

Agent Type Recommended Context Rationale
Planning agents Local Interactive refinement of plans
Implementation agents Background or Cloud Long-running, benefits from isolation
Review agents Local Interactive feedback needed
Documentation agents Background Can run while developer works

Best Practices:

  • Use target: github-copilot for agents intended for cloud execution
  • Design agents to work autonomously for background execution
  • Include clear success criteria so background/cloud agents know when complete
  • Consider using handoffs to transition from planning (local) to implementation (background/cloud)