Modern software rarely lives in one repository. It's a web service here, a mobile client there, a shared library, a data pipeline, three internal tools, and a fork of somebody else's project — each with its own conventions, build system, and blast radius. Most advice about AI coding agents doesn't seem to know this: it's written as if \"the codebase\" is one directory, and stops working the moment real engineering happens at the seams between repositories. Claude Code Across Multiple Codebases is the field guide for engineers who want to bring an AI coding agent into that reality without losing control of it. Drawing on real workflow patterns rather than theory, it builds a complete operating model, piece by piece: how to lay out a workspace that holds several repositories at once, how to write a two-tier CLAUDE.md configuration system so shared conventions and repo-specific rules never collide, how to use git worktrees and subagents to run genuinely parallel agent work without file collisions or lost context, and how to scope permissions so an agent's reach always matches a repository's actual risk. From there the book goes further than most guides even attempt: testing and validating changes that cross repository boundaries, keeping documentation useful to both humans and agents, securing secrets and credentials at workspace scale, working responsibly with vendored and forked code, debugging defects whose cause and symptom live in different repositories, managing cost and model selection deliberately, migrating an estate that already exists into this system, recognizing and recovering from the specific ways it all tends to degrade, and rolling the whole thing out as a durable team standard — not just a personal habit. Every pattern is something you could set up this afternoon: a workspace directory, a registry file, a permission rule, a worktree. Ten detailed case studies show how the same patterns land differently across a five-service backend team, a mobile-and-SDK triad, a large legacy monorepo, and a solo open-source maintainer working across forks. No hype, no magic — just a working system for turning Claude Code from a single-repo assistant into a disciplined operator across your entire multi-repo estate, individually or as a team.", "short_description": "A practical field guide to running Claude Code across multiple repositories at once — workspace layout, layered CLAUDE.md configuration, git worktrees, subagent delegation, permission hygiene, and team rollout, built from real workflow patterns rather than theory.
