Quickstart & First Session

px0 is an IDE built for reviewing AI-generated code, optimized for speed. It turns your browser into a zero-latency console with native Git and GitHub integrations, instant search across massive codebases, and seamless handoff to local AI coding harnesses. This guide walks you through launching your first session, navigating the interface, and driving multi-turn agent threads.

Launching Your First Workspace or PR Review

Open any directory, repository, or GitHub pull request by passing it to px0:

# Open current working directory
px0 .

# Open any repository path
px0 ~/projects/backend

# Review a GitHub pull request directly in the browser
px0 https://github.com/owner/repo/pull/123

px0 instantly scans the tree or checks out the PR in a few milliseconds, launches an embedded HTTP server, and opens your default browser.

Interface Anatomy

The px0 interface is designed for high-density reading and zero visual clutter. It consists of six primary regions:

px0 Interface Overview

1. Left Activity Rail

The narrow leftmost bar lets you toggle sidebar panels:

  • Files (Explorer): View folder hierarchy and changed files.
  • Workspace Search: Full-text regex search across the repository.
  • Symbol Outline: Instant symbol hierarchy for the active file.
  • Themes: Cycle or select from 14 built-in syntax themes.
  • Shortcuts (?): Show the interactive keyboard shortcut sheet.

2. Collapsible Sidebar

  • Project Root: Displays the root folder name.
  • Changed Files Filter (*): Filters the tree to show only files with git changes (M, A, D, U).
  • File Tree Context Actions: Right-click or click the three-dots button on any file or folder to copy its relative path, file name, or absolute path.
  • Reindex Button (↻): Re-scans the project tree and updates git diff badges in under 50 ms.
  • Git Panel: Stage, commit, generate AI messages, push, and pull at the bottom of the sidebar.

3. Tab & Breadcrumbs Bar

  • Displays active tabs with language icons.
  • Tab Context Menu: Right-click any tab to access Close, Close Others, Close to the Right, Close to the Left, or Close All.
  • Click any path segment in the breadcrumbs bar to reveal that directory in the file explorer.
  • Reopen closed tabs quickly with Ctrl+Shift+T (Cmd+Shift+T on macOS).

4. Virtualized Code Viewport

  • Windowed Rendering: Opening a 500,000-line file costs the same memory as a 10-line file. Only the visible ~60 rows are mounted in the browser DOM.
  • Permanent Line Numbers: Clean, non-intrusive line numbers remain visible by default in the gutter.
  • Line Hover Thread Icon: Hovering any line number displays a thread icon to start a thread, stage an inline edit, or leave a PR review comment.
  • Selection & Context Actions: Select code with your mouse or classic Shift and Ctrl keyboard navigation. Right-click any selection, click footer actions, or press Alt+T / Alt+E to converse with or dispatch edits to your coding harness.
  • Hover Inspection: Move your mouse over any identifier to inspect its type signature and documentation.

5. Right Inspector & Threads Pane

Located on the right side of the window (with a header button to reopen when collapsed):

  • Threads: Conduct persistent multi-turn conversations with your coding harness, view real-time tool steps (Read, Edit), inspect changed file chips, and manage staged batch edits.
  • References: View all workspace references for an identifier (Shift+F12).
  • Symbols: Document symbol outline.
  • Calls: Call hierarchy trails (incoming callers and outgoing callees).
  • Search: In-file and workspace search results.

6. Status Bar

Located at the bottom of the window, the status bar displays:

  • Active coding harness (Claude Code, Antigravity, Gemini CLI, Cursor Agent, OpenCode, Codex, Aider, or Goose) and selected model
  • Language mode (e.g. Go, Rust, TypeScript, Python)
  • Line count and file size
  • Cursor position (line and column)
  • Language Server (LSP) status indicator and install recipe trigger
  • Interactive CPU and RAM process metrics popover

Core Navigation & Editing Workflows

1. Jump to Any File (Ctrl+P or Cmd+P)

Press Ctrl+P (or Cmd+P on macOS) to open the fuzzy file finder. Type any part of a file path (for example srv/http or pkg/index) and press Enter to open it immediately.

2. Full Workspace Search (Ctrl+Shift+F or Cmd+Shift+F)

Press Ctrl+Shift+F to open the full-text search panel. Searches execute in parallel across all CPU cores, bypassing .gitignore files automatically. Closing the panel automatically cancels in-flight searches.

3. Jump to Symbol in File (Ctrl+Shift+O or Cmd+Shift+O)

Quickly jump to functions, methods, structs, or classes within the current file. Symbols are extracted via LSP when available, or instant regex parsing as fallback.

4. Inspect Git Diffs (Ctrl+D or Cmd+D)

Press Ctrl+D on any modified file to view side-by-side or unified diffs against HEAD. Uncommitted agent changes are highlighted with green and red gutter markers and Chroma syntax highlighting.

5. Start a Multi-Turn Thread (Alt+T or Option+T)

Highlight code or position your cursor and press Alt+T (or click the line thread icon). Type your prompt to start a conversation in the Threads pane. Follow up across multiple messages as the agent reads files, executes tool steps, and suggests modifications.

6. Edit with Coding Agent (Alt+E or Option+E)

Highlight any range of code in source view or git diff view and press Alt+E (or right-click). Type your instruction into the comment box. Press Enter to queue the comment for a batch, or Ctrl+Enter (Cmd+Enter on macOS) to apply immediately. px0 streams the agent output, guards against conflicting edits, reloads modified files automatically, and saves the run as a thread.

Stopping px0

When you are done reviewing code, switch to your terminal and press Ctrl+C. The server cleanly stops child language server processes and terminates without leaving temporary cache files or lockfiles on your system.