basecamp

Claude Code multi-project workspace launcher with custom prompts and isolated worktrees.

git clone https://github.com/btimothy-har/basecamp.git
cd basecamp && uv run install.py
basecamp setup
basecamp start basecamp

Why basecamp?

When working with Claude Code across multiple projects, you face friction:

• Scattered context — Each project needs different prompts, working styles, and domain knowledge
• Branch conflicts — Parallel conversations on the same repo compete for the working directory
• Repetitive setup — Re-configuring directories and prompts for each session

basecamp solves this with a single command that:

1. Replaces Claude's default system prompt — Full control over behavior, consistency across sessions, tailored to your workflow (Claude Code still appends its tool definitions)
2. Configures project context — Loads project-specific prompts and working styles automatically
3. Supports isolated worktrees — Use -l <label> to work in a labeled worktree for parallel conversations
4. Manages multi-repo projects — Groups related repositories under one project definition

Features

Multi-Project Management

Define projects in ~/.basecamp/projects.json with their directories, descriptions, and working styles. Launch any project with basecamp start <project>.

{
  "my-project": {
    "dirs": ["GitHub/my-project", "GitHub/my-project-docs"],
    "description": "My awesome project",
    "working_style": "engineering"
  }
}

Custom Prompts

Layer prompts for different contexts:

Layer	Purpose
Environment	CLI context, Python/uv usage, project paths
Core	Working principles, task management, tool usage
Working Style	Role definition, communication style, code quality practices
Project Context	Domain knowledge, project-specific patterns

Git Worktree Isolation

Use -l <label> to work in an isolated worktree:

basecamp start myproject -l auth      # Create or re-enter "auth" worktree
basecamp start myproject -l bugfix    # Create or re-enter "bugfix" worktree

Worktrees live in ~/.worktrees/<repo>/<label>/ with branches named wt/<label>.

Installation

Requires uv and Claude Code.

git clone https://github.com/btimothy-har/basecamp.git
cd basecamp
uv run install.py           # interactive (prompts for editable mode)
uv run install.py -e        # editable (recommended for development)
uv run install.py --no-editable

This installs two tools (basecamp and observer) and saves the install directory to ~/.basecamp/config.json.

Then initialize the environment:

basecamp setup                     # check prerequisites, scaffold dirs, create default config

If basecamp or observer aren't in your PATH:

export PATH="$HOME/.local/bin:$PATH"

Upgrading

uv tool upgrade basecamp-core && uv tool upgrade basecamp-observer

Uninstalling

uv tool uninstall basecamp-core && uv tool uninstall basecamp-observer

Usage

Launching Projects

basecamp start <project>                # Start in project directory
basecamp start <project> --resume       # Resume previous conversation (-r)
basecamp start <project> -l <label>     # Work in labeled worktree (creates if new)

Opening in VS Code

basecamp open <project>                  # Open basecamp + project directories
basecamp open <project> -n               # Open in new window
basecamp open <project> -l <label>       # Open in existing worktree

Managing Worktrees

basecamp worktree list <project>         # List worktrees for project
basecamp worktree list --all             # List all worktrees (-a)
basecamp worktree clean <project>        # Interactive cleanup
basecamp worktree clean <project> <name> # Remove specific worktree
basecamp worktree clean <project> --all  # Remove all worktrees
basecamp worktree clean <project> -f     # Force removal (--force)

Listing Projects

basecamp projects                        # Show available projects

Configuration

Projects are defined in ~/.basecamp/projects.json:

{
  "web-app": {
    "dirs": ["GitHub/web-app"],
    "description": "Main web application",
    "working_style": "engineering"
  },
  "data-pipeline": {
    "dirs": ["GitHub/pipeline", "GitHub/pipeline-config"],
    "description": "ETL pipeline and configuration",
    "working_style": "engineering",
    "context": "pipeline"
  }
}

Field	Required	Description
dirs	Yes	Paths relative to $HOME. First is primary (cwd), rest are --add-dir
description	No	Shown in basecamp projects list
working_style	No	Loads ~/.basecamp/prompts/working_styles/{name}.md (user override) or package default
context	No	Loads ~/.basecamp/prompts/context/{name}.md for project context

Prompt System

basecamp replaces Claude Code's default system prompt via the --system-prompt flag. This gives you:

• Full control — Define how Claude approaches work, not Anthropic's defaults
• Consistency — Same behavior across sessions; immune to upstream prompt changes
• Customization — Prompts designed for your specific workflow

Claude Code still appends its own tool definitions section (tool schemas, permissions, MCP servers) which cannot be modified. basecamp controls everything else.

Prompt Assembly

The system prompt is assembled from layered sources:

Runtime context (paths, platform, date)
         ↓
environment.md (CLI usage, Python/uv)
         ↓
working_styles/{name}.md (if configured)
         ↓
system.md (working principles, tools, agents)

Override system.md by placing a file at ~/.basecamp/prompts/system.md.

Project context is injected separately via a SessionStart hook, not included in the system prompt. This places the project context alongside any CLAUDE.md file in the primary repository.

Working Styles

Style	Description
engineering	Partner role, quest-based work, code quality focus, frequent check-ins
advisor	Advisor role, efficient discovery, direct communication, decision support

Create custom working styles in ~/.basecamp/prompts/working_styles/.

Project Context

For multi-repo projects, add cross-repo context in ~/.basecamp/prompts/context/. The context field in project config points to this file.

Single-repo projects typically use CLAUDE.md in the repo itself.

Plugins

basecamp includes optional plugins for extended functionality. These are complementary, not required.

Plugin	Description
bc-collab	Collaborative discovery and planning for ideation and requirements
bc-eng	Code review, PR workflows, testing patterns, Python/SQL development
bc-cursor	Discovers .cursor/*.mdc context files
bc-gpg-check	Verifies GPG card before git commit/tag

Installing Plugins

From within a Claude Code session started via basecamp:

/plugin marketplace add /path/to/basecamp
/plugin install bc-eng@basecamp

The first command registers basecamp as a marketplace (it discovers .claude-plugin/marketplace.json). The second installs a plugin from it. Available plugins: bc-collab, bc-cursor, bc-eng, bc-gpg-check.

Create custom plugins in plugins/ following Claude Code plugin docs. Plugins in plugins/private/ are gitignored.

License

Apache 2.0