edobreque/clens

cLens — Session Observability for Claude Code

Local-first session capture and analysis for Claude Code agents. See what your agent actually did — every tool call, backtrack, decision, and reasoning step — without any network dependencies.

What it does

cLens hooks into Claude Code to capture complete session traces as local JSONL files. Every tool call, session lifecycle event, and agent message is appended to a flat file in your project — no network, no server, no external dependencies. After a session, the distill command runs 23 extractors to surface decision points, backtracks, reasoning patterns, edit chains, plan drift, multi-agent communication, and more for post-hoc analysis.

Key capabilities

• Session capture — zero-config hooks, ~2ms overhead per event
• Backtrack detection — find where agents reversed course and why
• Decision analysis — trace decision points through agent reasoning
• Edit chains — link thinking blocks to the code changes they produced
• Plan drift — compare intended spec vs actual execution
• Multi-agent tracing — communication graphs, team metrics, agent trees
• Interactive TUI — explore sessions with keyboard-navigable tabs
• OpenTelemetry export — bridge to existing observability stacks

Prerequisites

Bun >= 1.0

Quick Start

npm install -g clens       # or: bun install -g clens

Then in any project:

clens init                          # install hooks
# use Claude Code normally
clens list                          # see captured sessions
clens distill --last                # analyze latest session