guanghu/docs/adr/0150-github-copilot-cli-agent-adapter.md

type, id, title, status, date, supersedes

type	id	title	status	date	supersedes
ADR	0150	GitHub Copilot CLI agent adapter	active	2026-07-02

Context

Tolaria already exposes several app-managed local AI agent adapters through one normalized AI panel contract. GitHub Copilot CLI is a mainstream local agent with programmatic copilot -p ... execution, per-session tool permissions, current-directory path scoping, custom instructions support including AGENTS.md, and MCP server support.

Users who prefer Copilot should not have to leave Tolaria or manually configure a generic/custom agent to get vault-aware assistance.

Decision

Tolaria adds GitHub Copilot as a first-class local agent with product-facing id copilot.

The desktop backend:

• discovers copilot through PATH, login-shell lookup, and common local install locations including npm, pnpm, Bun, Mise, asdf, nvm-managed Node versions, Homebrew, and Windows npm/pnpm/Scoop shims
• runs copilot -p <prompt> -s --no-ask-user from the active vault directory
• passes Tolaria MCP as a per-session --additional-mcp-config JSON payload instead of mutating ~/.copilot/mcp-config.json
• uses Safe mode with --available-tools=write,tolaria, --allow-tool=write,tolaria, and --deny-tool=shell
• maps Power User mode to --allow-all-tools
• intentionally avoids --allow-all, --yolo, --allow-all-paths, and --allow-all-urls
• streams line-oriented stdout through the shared agent event contract and registers the child process under the request-scoped stream id for cancellation
• maps authentication, organization policy, subscription, and directory-trust stderr into Copilot-specific setup guidance

The renderer adds Copilot to the shared AI-agent registry so the onboarding prompt, Settings target picker, command palette switch command, AI workspace target groups, and persisted agent:copilot target all use the same definition.

Consequences

• Users can select GitHub Copilot anywhere Tolaria lists local/app-managed AI agents.
• App-managed Copilot sessions stay vault-scoped by current working directory and Copilot's default path verification unless the user chooses Tolaria Power User, which still does not bypass all paths or URLs.
• Tolaria does not persist Copilot credentials, model-provider secrets, or durable third-party MCP files.
• Native end-to-end QA requires a local Copilot CLI install and authentication; automated tests use fake executables for deterministic streaming and error coverage.
• Future Copilot CLI permission or MCP flag changes must update this adapter and ADR rather than falling back to broad --allow-all / --yolo behavior.