claude-devtools

Parses Claude Code's JSONL session files stored at ~/.claude/projects/ to reconstruct the complete execution trace of each turn, including file reads, tool calls, token consumption, and context injections. Uses a streaming JSONL parser with caching strategy to handle large session files efficiently without loading entire logs into memory, enabling post-hoc analysis of sessions regardless of execution environment (terminal, IDE, or wrapper tool).

Reverse-engineers the per-turn context window contents by analyzing session logs and attributing tokens across discrete categories: CLAUDE.md files, skill activations, tool I/O, thinking blocks, and system prompts. Uses a token accounting system that maps each context component back to its source in the session log, enabling developers to understand exactly why the context window grew or shrank at each step.

Implements an auto-update mechanism using Electron's update framework with code signing (macOS) and notarization to ensure app integrity. Detects new releases from GitHub, downloads updates in the background, and prompts users to install with a visual dialog. Supports staged rollouts and rollback on update failures.

Scans the Claude projects directory to discover all projects and their sessions, using a path encoding scheme that creates stable Project IDs from file paths. Handles both local paths and remote SSH paths uniformly, enabling a single project ID to reference sessions across different machines. Caches project metadata to avoid repeated directory scans.

Connects to remote machines via SSH/SFTP to discover and parse Claude Code sessions running on remote servers, enabling inspection of remote session logs as if they were local. Implements an SSH Connection Manager that handles authentication (key-based and password), remote path resolution, and transparent SFTP file operations, with a caching layer to avoid repeated remote file transfers. Supports multi-machine setups where developers run Claude Code on different servers.

Monitors the ~/.claude/projects/ directory (local and remote) for new or updated session files using file system watchers, automatically discovering new sessions and refreshing existing session data without requiring manual refresh. Implements a Project Scanner that enumerates project directories, detects new sessions, and triggers incremental JSONL parsing for updated files. Uses debouncing and throttling to prevent excessive re-parsing during rapid file writes.

Renders a visual timeline of session turns with expandable details for each turn, showing tool calls, file reads, token consumption, and context state. Implements a React-based UI with virtualization to handle sessions with hundreds of turns efficiently, combined with a command palette for quick navigation and filtering. Each turn can be expanded to show full tool call arguments, results, and context composition.

Implements a configurable notification system that triggers alerts based on session events (e.g., tool call failures, context window near capacity, session completion). Uses a Notification Manager with a trigger system that evaluates conditions against session data and supports filtering/throttling to prevent notification spam. Notifications can be configured per-project or globally, with support for custom trigger expressions.

Aggregates token usage and cost data across multiple sessions, projects, and time periods to provide analytics dashboards showing trends, per-project costs, and cost-per-task metrics. Implements a Session Analyzer that computes statistics from parsed session data and supports filtering by date range, project, or session type. Integrates with Claude API pricing to calculate estimated costs based on token counts.

Implements a multi-context system using Electron's IPC (Inter-Process Communication) to separate concerns between the main process (file I/O, SSH, session parsing) and renderer process (UI, visualization). Uses a service context API that abstracts file operations and session parsing behind IPC handlers, enabling the renderer to request data without direct file system access. Supports concurrent session parsing and SSH operations in the main process while keeping the UI responsive.

Provides a settings interface for configuring Claude root directory, SSH connections, notification triggers, and UI preferences, with IPC-based persistence to store configuration in the main process. Implements Config IPC Handlers that validate and persist settings to disk, with support for per-machine and per-user configuration. Includes automatic Claude root detection to simplify initial setup.

Exposes an HTTP API server running alongside the Electron app to enable external tools and integrations to query session data and trigger notifications. Implements REST endpoints for session queries, cost analytics, and notification triggers, with optional authentication. Enables integration with CI/CD pipelines, monitoring systems, and custom dashboards.