VS Code 1.135 runs agent harnesses in a dedicated process on a new Agent Host Protocol
VS Code 1.135 ships the agent host, which runs agent harnesses in a separate process on the new Agent Host Protocol so one session can be attached from several windows, with its Copilot agent built on the Copilot SDK to match the Copilot CLI and standalone app. A developer can now pick up a Copilot or Claude session started in another application, invoke the experimental /rubber-duck command for a second opinion from a complementary model, and read a per-model breakdown of input, cached-input, and output tokens per chat turn. Sandboxing for the local agent harness went the other way — the rollout was pulled back from 50% of users to 0%, opt-in only.
Source: code.visualstudio.com ↗
The agent host lets you connect to the same agent session from multiple VS Code windows.
Why this matters
- → Agent sessions now portable across VS Code windows and other apps
- → Token usage breakdown per chat turn helps track model costs
- → Rubber Duck adds second-opinion capability from complementary models