microkernel

name	microkernel
description	Use when building plugin or extension architecture: a stable core kernel with explicit extension points, plugin contracts, registration, isolation, versioning, and compatibility checks.

Microkernel / Plugin Architecture

Use this skill when the codebase needs a small core and independently variable plugins.

Fit

Use for CLIs, editors, rules engines, integrations, workflow engines, agent tools, and product variants. Avoid when variation is low or plugin isolation would add more complexity than it removes.

Agent Workflow

1. Read graphify-out/GRAPH_REPORT.md.
2. Run graphify query "microkernel plugin extension points core adapters".
3. Identify stable core responsibilities versus variable behavior.
4. Define extension contracts before extracting plugins.
5. Move one variable feature behind a plugin boundary.
6. Add compatibility and registration checks.

Target Shape

codebase/kernel/
  contracts           # plugin interfaces, capabilities, lifecycle
  registry            # discovery, validation, ordering
  runtime             # core orchestration
codebase/plugins/
  <plugin-name>/
    entrypoint        # manifest + implementation
    tests/

Implementation Rules

• Kernel owns orchestration, lifecycle, contracts, capability negotiation, and safe defaults.
• Plugins own optional behavior only; they must not mutate kernel internals.
• Plugin APIs are versioned and narrow.
• Registration validates name, version, capabilities, dependencies, and conflicts.
• Side effects are exposed through kernel-provided services, not global imports.

Migration Steps

1. Name the extension point.
2. Create contract and manifest types.
3. Implement an in-process registry.
4. Wrap one existing variation as the first built-in plugin.
5. Replace direct branching with registry dispatch.
6. Add contract tests reused by every plugin.

Verification

• graphify explain "registry" should show kernel-to-plugin direction, not plugin-to-kernel internals.
• Add tests for plugin registration, invalid manifests, lifecycle failures, and version mismatch.
• Search for plugin imports of kernel private paths.

Output Contract

Return: kernel boundary, extension points, plugin contract, migrated plugin, compatibility tests, and known limitations.