Claude Code Projects: Retire an API Across 3 Repos

On September 17, 2026, Anthropic quietly shipped one of the biggest changes to how you actually manage agentic coding: a rebuilt Claude Code Projects. It went from "a folder of chats and reference files" to something closer to a chief-of-staff conversation that spins up, tracks, and reports back on parallel coding threads for you. A week later it's still spreading through dev Twitter/X and Hacker News threads, alongside coverage from VentureBeat, MarkTechPost, and The New Stack, because it solves a problem every agentic-coding user has run into: running five Claude Code sessions at once means you become the scheduler, repeating context in each one and manually checking which finished.

This guide walks through the whole feature end to end, using the exact real-world scenario Anthropic itself points to: retiring a deprecated API endpoint across three repositories (a backend service, a web app, and a mobile app) with one coordinator conversation instead of three separate terminals. By the end, you'll know how to create a project, write project instructions that every thread inherits, hand off multi-repo work, review the pull requests that come back, and avoid the usage traps that catch people in week one.