diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 0000000..cd43ca9
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,48 @@
+# Repository instructions for GitHub Copilot
+
+This repository is **IdentityLifecycleEngine (IdLE)**: a **generic, headless, configuration-driven identity lifecycle / JML orchestration engine** for **PowerShell 7+**.
+
+Use these instructions when suggesting or generating changes in this repo (chat, code review, coding agent).
+
+## Primary sources of truth
+
+- Agent operating manual: `AGENTS.md`
+- Coding and documentation rules: `STYLEGUIDE.md`
+- Contributor workflow + Definition of Done: `CONTRIBUTING.md`
+- Architecture: `docs/advanced/architecture.md`
+- Security + trust boundaries: `docs/advanced/security.md`
+
+If anything in this file conflicts with those, the more specific document wins.
+
+## Core constraints (do not violate)
+
+- **PowerShell 7+ only.**
+- **Headless core:** `IdLE.Core` must not depend on UI frameworks, interactive prompts, or service/web hosts.
+- **Plan → Execute separation:** planning is deterministic; execution runs the plan as-built.
+- **Configuration is data-only:** workflow PSD1 files must not contain ScriptBlocks or executable objects.
+- **Steps vs providers:**
+  - Steps are idempotent intent/convergence logic and must not do authentication.
+  - Providers handle external system access and authentication via `Context.AcquireAuthSession(...)`.
+
+## Style and quality gates
+
+- Use **approved PowerShell verbs** and **Verb-Noun** naming.
+- Use **4 spaces indentation**, UTF-8, LF.
+- Public commands must have **comment-based help** (`.SYNOPSIS/.DESCRIPTION/.PARAMETER/.EXAMPLE/.OUTPUTS`).
+- Avoid drive-by refactors. Keep PRs focused on **one issue/theme**.
+- Add/adjust **Pester tests** for new behavior or bug fixes.
+- Run repo scripts:
+  - `./tools/Invoke-IdlePesterTests.ps1`
+  - `./tools/Invoke-IdleScriptAnalyzer.ps1`
+
+## Documentation rules
+
+- Do not edit generated references under `docs/reference/` by hand.
+  - Regenerate via the repository tools as documented in `CONTRIBUTING.md`.
+
+## Git / PR conventions
+
+- Use small, reviewable commits; one logical change per commit.
+- Prefer branch names like `issues/<issueNumber>-<sanitizedTitle>` for human work.
+
+> Note: **Copilot coding agent** is restricted to creating/pushing to branches that start with `copilot/` on GitHub.com.