feat(extension): add VS Code extension and extension bundle for GitHub Copilot Chat

[Andrew Coates (coatsy)]

Summary

This PR adds a VS Code extension that packages the existing agents and skills from this repository for use inside GitHub Copilot Chat. Instead of requiring a Claude Code CLI or GitHub Copilot CLI setup, users can install a single VS Code extension (or an extension bundle) and immediately access all four Copilot Studio agents — Author, Manage, Test, and Troubleshoot — directly in the VS Code chat panel.

What's included

Copilot Studio Skills extension (extension/)

A VS Code Chat extension that takes the agents (.agent.md files) and skills (SKILL.md files + supporting references) from this repository and packages them as a .vsix for the VS Code Marketplace. At build time, a template-driven process (package.template.json) discovers all agents, skills, hooks, templates, scripts, and reference files and registers them as extension contributions. This means:

• All four agents (Author, Manage, Test, Troubleshoot) are available as chat participants in GitHub Copilot Chat
• All skills are bundled and available for the agents to invoke
• Reference schemas, connector definitions, templates, and bundled scripts are included — the extension is self-contained
• No manual file copying or plugin installation required

Copilot Studio Development Bundle (extension-pack/)

An extension pack that installs both:

1. Copilot Studio Skills (this extension)
2. Copilot Studio (ms-copilotstudio.vscode-copilotstudio) — the official Microsoft extension for push/pull/clone operations

This gives users a one-click install for the complete agent development experience.

Build and CI/CD

• extension/test-local.sh — local build script that stages artifacts from across the repo, generates package.json from the template by discovering agents and skills, strips YAML frontmatter from the README, and packages the VSIX. Supports --package-only (build without installing) or full build-and-install into VS Code.
• .github/workflows/build-extension.yml — CI workflow that builds and validates the VSIX on every push
• .github/workflows/publish-extension.yml — publish workflow for pushing to the VS Code Marketplace

Local testing with a dev build of VS Code

For contributors who want to debug and test the extension in an isolated environment, this PR includes tooling to build VS Code from source and use it as a dedicated extension debug host:

• extension/setup-devhost.sh — idempotent script that clones the VS Code repository, installs dependencies, and builds a self-hosted VS Code instance. Supports --shallow for faster initial clone, --skip-launch for CI, and configurable --vscode-dir, --user-data-dir, and --extensions-dir paths.
• .vscode/launch.json — pre-configured debug configurations:
  • "Launch Extension (Dev Host)" — launches the Extension Development Host using the locally built VS Code with isolated user data and extensions directories, with a pre-launch task that packages the extension first
  • "Attach to Extension Host" — attaches the debugger to an already-running Extension Development Host
• .vscode/tasks.json — build tasks for "Package Extension" and "Build and Install Extension" that drive test-local.sh

The dev host approach avoids cross-contamination with the developer's primary VS Code installation — extension state, settings, and other extensions remain completely separate, giving a clean environment for reproducing issues and stepping through integration code.

Dev host prerequisites

Requirement	Version	Notes
Git + Git LFS	2.x+	Required by the VS Code repo for binary assets
Node.js	22+	Check vscode/.nvmrc for the exact minor version
Python	3.11+	Required by native module compilation (node-gyp)
C++ toolchain	Platform-specific	VS 2022 Build Tools on Windows, Xcode CLT on macOS, build-essential on Linux

Documentation

• README.md — updated with the VS Code extension bundle as the recommended installation method, with Claude Code / Copilot CLI instructions preserved as alternatives
• SETUP_GUIDE.md — expanded with VS Code extension walkthrough
• CONTRIBUTING.md — updated with extension build instructions
• extension/PACKAGING.md — detailed packaging and publishing guide
• extension/docs/LOCAL_DEV_HOST.md — full guide to building VS Code from source for extension debugging
• extension/docs/DEBUG_CONFIG.md — launch.json configuration reference
• Architecture Decision Records:
  • ADR-001: Artifact file strategy (how the build discovers and stages files)
  • ADR-002: Dev host tooling location (why setup scripts live in extension/)

How the build works

The extension build process (test-local.sh):

1. Creates a clean .staging directory
2. Copies agents from agents/*.md, renaming them to *.agent.md for VS Code compatibility
3. Copies skills/, scripts/, templates/, reference/, and hooks/ directories
4. Reads extension/templates/package.template.json as the base manifest
5. Runs a Node.js script that scans staged directories, extracts agent names/descriptions from YAML frontmatter, and populates the contributes section of package.json
6. Strips YAML frontmatter from Markdown files (required for Marketplace rendering)
7. Packages everything into a .vsix using @vscode/vsce

This means the extension stays in sync with the repo — when new skills or agents are added upstream, the build automatically discovers and includes them.

TODOs

• Update publisher from coatsy to the official Microsoft publisher
• Remove/change all coatsy references (repo, etc)
• Get Marketplace publishing token for the new publisher
• Update the PAT secret used by the publish workflow

Stats

32 files changed, ~2,400 lines added

[Giorgio Ughini (GiorgioUghini)]

Lots of commits -- thank you Andrew!

I'd love to know more about this: from my understanding this will package the plugin into a VS Code Extension, which would mean we would need to manage updates by our own? If we accept this in the main branch, would it mean that people would not need the Copilot Studio Extension anymore?

[Andrew Coates (coatsy)]

Hi Giorgio Ughini (@GiorgioUghini)

this will package the plugin into a VS Code Extension

Correct

which would mean we would need to manage updates by our own?

The CI/CD pipeline publishes the extension and the bundle automatically each time we (you) do a release

would it mean that people would not need the Copilot Studio Extension anymore?

No, the copilot studio extension is still a pre-requisite, but installing the bundle would mean that people get both the copilot studio extension and the agents/skills extension

[Andrew Coates (coatsy)]

Giorgio Ughini (@GiorgioUghini) more explanation in a blog post I helped copilot write: https://github.com/coatsy/skills-for-copilot-studio/blob/coatsy/vscode-extension/extension/docs/blog/blog-post.md

[Chris Garty (ChrisGarty)]

Andrew Coates (@coatsy), perhaps this would be ideal as a separate repository that builds upon the standard VS Code Extension for Copilot Studio and these skills? That would allow VS Code users to take advantage of it without adding substantially to the code base of this repository. Then it could be iterated separately to evolve the VS Code capabilities.
Thoughts?

[Andrew Coates (coatsy)]

Chris Garty (@ChrisGarty) - this could make sense. We might even include it in the suite of hve-core extensions (see https://marketplace.visualstudio.com/search?term=hve%20core&target=VSCode&category=All%20categories&sortBy=Relevance).

I guess we can add a workflow that watches this repo and rebuilds/republishes whenever a new release is pushed here.