0001. TypeScript, ports-and-adapters core

• Status: accepted
• Date: 2026-10-03
• Issue: #1

Context

Pixel has to be useful on Discord now, and on other platforms later, without rewriting features each time. Interactive chat (commands, replies) and outbound announcements (space open/closed) are different jobs.

Decision

• TypeScript on Node.js LTS, ESM only. Strict types, no any. All user-facing text is English.
• Ports-and-adapters. Dependency direction is adapters → core ← features → services. core imports nothing from the other folders.
• Two kinds of adapter. Interactive adapters turn a platform event into a PlatformActor, call the dispatcher, and render a Reply. Publisher adapters only post announcements. Discord is both. Mastodon is publisher-only. Telegram is later.
• Platform SDKs stay in their adapter. discord.js is imported only in src/adapters/discord/. When the core needs platform data, it takes a port (core/ports/) that the adapter implements.
• One dispatcher. Every command is rate-limited, identified, authorised, then handled. Features never talk to a platform.

Consequences

• A new feature is one folder under src/features/ and needs no platform plumbing.
• A new platform is an adapter; existing features do not change.
• Features are tested against a fake CommandContext. Adapter tests use plain objects, never a live Discord connection.