The previous three posts covered how events flow from the SDK to the UI, how the timeline renders, and how tool cards visualize. This final post looks at SwiftWork's infrastructure — how data is stored, how state is restored, how Markdown is rendered, how code is highlighted, and how API keys are managed. These components are independent, but all essential to making the app usable. SwiftWork uses
Every AI app I've shipped recently rewrote the same plumbing. The OAuth dance for Slack. Encrypted storage for an API key. Refresh-token logic that finally fails on the 3rd call after an hour. Wiring up an MCP client to a server behind a bearer token someone pasted into a Notion page.