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Core concepts

Before diving deep into p0, familiarize yourself with the key concepts that shape how you work with the AI coding assistant. These building blocks work together to create a safe, productive development workflow.

Foundational concepts

Workspaces

Workspaces

A workspace is a container for one or more git repositories, along with shared settings, coding standards, and plugins. Workspaces let you:
  • Work across multiple repos in a unified environment
  • Define project-wide conventions and preferences
  • Share context between sessions
  • Install workspace-scoped plugins
Think of a workspace as your project’s home base in p0.

Sessions

Sessions

A session represents a single coding task within a workspace. Each session:
  • Gets its own isolated git worktree for safety
  • Has a dedicated chat thread for communication
  • Can run in Plan mode (read-only) or Agent mode (full execution)
  • Tracks all changes and tool executions
Sessions keep your work organized and your main branch protected.

Modes

Plan vs Agent modes

p0 operates in two distinct modes:Plan mode (read-only):
  • Analyzes your codebase without making changes
  • Generates detailed implementation plans
  • Researches files and dependencies
  • Safe for exploration and brainstorming
Agent mode (execution):
  • Implements changes using real tools
  • Runs bash commands, edits files, searches the web
  • Shows real-time tool output
  • Creates commits and manages git
Start with Plan, switch to Agent when ready.

Spec-driven workflow

Spec-driven workflow

p0 follows a five-phase pipeline for complex features:
  1. Product spec: Define what you’re building and why
  2. Tech spec: Plan the technical implementation
  3. Implementation: Execute the changes
  4. Pull request: Review and merge
  5. Post-PR: Follow-up tasks and refinements
This structured approach ensures quality at every step.

Tools

Real-time tools

When running in Agent mode, p0 uses tools to interact with your codebase:
  • Bash: Run terminal commands
  • File operations: Read, write, edit files
  • Web search: Research APIs and documentation
  • Git operations: Commit, branch, diff
Every tool execution is visible in real-time with full output, giving you complete transparency into what p0 is doing.

Sub-chats

Sub-chats

Complex sessions can have multiple conversation threads called sub-chats:
  • Break large tasks into focused discussions
  • Work on parallel concerns simultaneously
  • Keep related context together
  • Switch between threads without losing progress
Sub-chats help manage complexity in long-running sessions.

How it all fits together

Here’s how these concepts work together in a typical p0 workflow:
  1. You create a workspace for your project and add repositories
  2. You start a session for a specific task (e.g., “Add user authentication”)
  3. p0 operates in Plan mode to analyze and create a plan
  4. You review the plan and switch to Agent mode for execution
  5. p0 uses tools (bash, file edits) to implement changes in an isolated git worktree
  6. For complex features, you follow the spec-driven workflow with multiple phases
  7. You use sub-chats to work on different aspects in parallel
  8. When complete, you review the diff and create a pull request

Git worktree isolation

One of p0’s most important safety features is git worktree isolation. Each session runs in its own worktree, which means:
  • Your main branch stays clean and untouched
  • Multiple sessions can run concurrently without conflicts
  • You can experiment freely without risk
  • Failed sessions don’t pollute your workspace
Learn more about git worktree isolation.

Available models

p0 is powered by Anthropic’s Claude models. You can switch between models using the /model command or the model selector in the chat header:
  • Claude Sonnet — fast, efficient performance for most coding tasks (default)
  • Claude Opus — maximum capability for complex reasoning and planning
  • Claude Haiku — lightweight model for quick tasks

Next steps

Now that you understand the core concepts, explore specific areas: