ADR 0005: User-installable plugin system

• Status: Accepted
• Date: 2026-07-25
• Updated: 2026-07-25

Context

Built-in features alone are not enough. Users need to install and develop plugins that extend:

• commands
• panels
• agent tools
• skills

Decision

Adopt a first-party plugin system:

• directory-based plugin packages
• manifest.json contribution + permission declarations
• command palette integration
• agent tool registration support
• local install / enable / disable / uninstall
• default-deny permissions with explicit grants

Rationale

1. Enables user customization without forking the app
2. Safer than arbitrary Electron main-script loading
3. Serves both UI extension and agent extension
4. Leaves room for a later marketplace protocol

Consequences

Positive

• Extensible product surface
• Clear contribution model
• Aligns with skills/tools ecosystems

Negative

• Extra architecture and security complexity
• Needs management UI, validation, and auditing

Scope control

• MVP prioritizes local plugin loading, not marketplace
• First contributions: commands / panel / agentTools / skills
• Plugins are isolated and permissioned by default