@manuelvanrijn/copilot-instructions-plugin

An OpenCode plugin and Claude Code plugin that loads .github/instructions/ files into the AI agent's system prompt — following the same applyTo: convention as GitHub Copilot custom instructions.

Variants

This repo contains two plugin variants that share the same instruction source (.github/instructions/*.md):

| Variant | Target | Entry point | |---|---|---| | OpenCode plugin | OpenCode | src/index.ts (npm package) | | Claude Code plugin | Claude Code | .claude-plugin/ (hook-based) |

How it works

• .github/copilot-instructions.md is always injected if it exists — this is the repository-level instructions file used by GitHub Copilot
• Files with applyTo: are injected on-demand when the agent reads, edits, or writes a file matching the glob pattern
• Files without applyTo: are always injected at the start of every session

This means you can keep your existing .github/copilot-instructions.md and .github/instructions/ setup and it works in both Copilot and OpenCode without any duplication.

Installation

opencode plugin @manuelvanrijn/[email protected] --global

Or add it to your opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["@manuelvanrijn/[email protected]"]
}

Instruction file format

Same format as GitHub Copilot — YAML frontmatter with applyTo::

---
applyTo: "app/controllers/**"
---
# Controllers Guide

Your instructions here...

Multiple globs (comma-separated):

---
applyTo: "app/models/**, test/**"
---
# Models

No frontmatter = always active:

# General Rails Guidelines

Always use...

Debugging

Enable verbose logging:

COPILOT_INSTRUCTIONS_DEBUG=1 opencode

Tool: list_injected_copilot_instructions

The plugin exposes a tool the agent can call to report the current injection status:

list_injected_copilot_instructions

Output shows which files are injected, which are pending, and which file paths have been seen in the session.

Releasing

Publishing to npm is fully automated via .github/workflows/publish.yml, triggered by pushing a v*.*.* tag.

Use the release script from a clean main:

git switch main && git pull
./scripts/release.sh patch   # or: minor | major

The script:

1. Verifies the working tree is clean.
2. Bumps the version in package.json (npm version --no-git-tag-version).
3. Updates CHANGELOG.md: renames ## Unreleased to ## vX.Y.Z — YYYY-MM-DD and adds a fresh ## Unreleased section at the top.
4. Commits (chore: release vX.Y.Z), creates tag vX.Y.Z, and pushes both to origin/main.

The tag push then triggers the GitHub Actions workflow, which:

1. Verifies the tag matches package.json version.
2. Creates a GitHub Release with auto-generated notes.
3. Publishes to npm with --provenance (OIDC / sigstore).

License

MIT

Claude Code plugin

The .claude-plugin/ directory contains a Claude Code plugin variant that uses Claude hooks for the same lazy instruction loading.

How it works

• SessionStart adds always-active rules to Claude context.
• UserPromptSubmit extracts file paths from prompts and activates matching conditional rules.
• PreToolUse (Read, Write, Edit, Glob, Grep) tracks accessed files and activates matching rules.
• PreCompact preserves context paths across compaction.

Rules are delivered through Claude Code hook additionalContext, not systemMessage, so Claude receives them as hidden context instead of a user-facing warning. Current-session state is stored under Claude's persistent plugin data directory. When Claude resumes, active rules are re-sent because hook context is process-local even when the session id is reused.

Installation

For local development, register this checkout as a Claude Code marketplace and install the plugin:

claude plugin marketplace add /path/to/copilot-instructions-plugin
claude plugin install copilot-instructions@copilot-instructions --scope user

In Claude Code, the status helper is available as:

/list-copilot-instructions

If you previously installed the early development marketplace name, remove it before reinstalling:

claude plugin uninstall copilot-instructions@copilot-instructions-plugin --scope user

Publishing

This repo can act as the Claude marketplace source directly.

Add it to Claude Code with:

claude plugin marketplace add manuelvanrijn/copilot-instructions-plugin
claude plugin install copilot-instructions@copilot-instructions

For a public Claude marketplace listing, submit this repository through Anthropic's plugin submission flow after the repo is live.