GitHub Copilot

GitHub Copilot is available in VS Code, JetBrains IDEs, and the terminal via the gh copilot extension. devai:install configures it with workspace instructions and MCP server registration.

Prerequisites

GitHub Copilot subscription active on your GitHub account
VS Code with the GitHub Copilot extension, or a JetBrains IDE with the Copilot plugin
marko/devai installed (see Installation)

What devai:install writes

Running marko devai:install with Copilot detected produces the following files:

.github/copilot-instructions.md    # Workspace-level guidelines for Copilot Chat
.vscode/mcp.json                   # MCP server registration (marko mcp:serve)
AGENTS.md                          # Shared guidelines file (devai-managed marker block)

Copilot does not implement LSP registration and no skills are distributed for Copilot.

copilot-instructions.md

The .github/copilot-instructions.md file is read by Copilot Chat for every workspace session. The installer writes merged Marko guidelines inside a  marker block, so your own edits outside the markers survive re-runs (see Editing generated files):

Module structure and naming conventions
Available MCP tools
Project-specific guidelines from every installed package’s resources/ai/guidelines.md

MCP registration

The .vscode/mcp.json file registers marko mcp:serve as an MCP server using the servers key (not mcpServers). Each entry includes a type field for the transport. Copilot Chat’s agent mode can call tools like find_event_observers and validate_module when answering questions about your project.

AGENTS.md

devai:install writes the shared AGENTS.md guidelines inside a  marker block: created if absent, and on later runs only the marked region is refreshed, so content you add outside the markers is preserved. Remove the markers to take full ownership — devai then leaves the file alone. See Editing generated files.

Manual verification

Open your project in VS Code with Copilot enabled.
Open Copilot Chat and ask: What Marko MCP tools are available?
In agent mode, ask: Search Marko docs for "dependency injection" — search_docs should run and return results if a docs driver is installed.
Check that .github/copilot-instructions.md exists and .vscode/mcp.json uses the servers key.

Agent-specific tips

Agent mode: MCP tool calls require Copilot Chat to be in agent mode (#agent). Switch to it by clicking the agent icon in the chat panel.
gh copilot: The terminal extension does not yet support MCP. Guidelines from copilot-instructions.md are not loaded in the terminal context.