AI tool comparison
Ferretlog vs smolvm
Which one should you ship with? Here is the side-by-side panel verdict, pricing read, reviewer split, and community vote comparison.
Developer Tools
Ferretlog
git log for your Claude Code agent runs — local, zero dependencies
50%
Panel ship
—
Community
Free
Entry
Ferretlog is a zero-dependency pure Python CLI that treats your Claude Code session logs like a git repository. It parses the raw JSONL logs in `~/.claude/projects/` and gives you git-style history browsing, diff between runs, per-tool-call breakdowns, and cost/token stats — entirely locally, with no network calls and no configuration required. If you've been using Claude Code heavily, you've likely experienced the frustration of losing track of what changed across sessions, what tools were called how many times, and how much each session actually cost across sub-agent calls. Ferretlog makes that history explorable and comparable the same way `git log` makes code history explorable. This is an indie solo project from Eitan Lebras, submitted as a Show HN. It's genuinely useful as a power-user tool for anyone doing serious Claude Code work, especially those managing multi-session agent pipelines where debugging "what did the agent do last time?" is a real pain. The zero-dependency, local-only design means there's no trust surface and no setup friction.
Developer Tools
smolvm
Sub-200ms microVMs for sandboxing AI coding agents safely
75%
Panel ship
—
Community
Paid
Entry
smolvm is a lightweight microVM runtime built in Rust on top of libkrun, designed specifically for sandboxing AI coding agents and untrusted code execution. VMs cold-start in under 200ms and ship as portable `.smolmachine` files — think Docker images but hardware-isolated. It supports macOS (Apple Silicon and Intel) and Linux, with opt-in networking so that untrusted code can't exfiltrate credentials or phone home by default. The project includes an explicit AGENTS.md to help coding agents understand how to use it, and was built with autonomous code execution in mind. When an AI agent needs to run user-submitted code or iterate on its own suggestions, smolvm gives it a proper hardware sandbox rather than a leaky container. Version v0.5.18 landed April 17, 2026. With AI coding agents increasingly running arbitrary code in tight loops, the security story around containerization has become critical. smolvm fills a real gap: fast enough to not break agentic workflows, isolated enough to actually protect the host machine and credentials. It surfaced on Hacker News with 259 points and strong technical discussion, suggesting genuine resonance with the developer community building agentic tools.
Reviewer scorecard
“If you run Claude Code daily, you need this immediately. Being able to diff two sessions like git commits and see exactly which tools fired and what they cost is something that should have existed from day one. Zero-dependency Python means it just works.”
“This is the missing layer for anyone running AI agents that execute code. Docker containers have always been too porous for untrusted execution, and smolvm's sub-200ms coldstart means you can spin a fresh VM per agent turn without killing your latency budget. The AGENTS.md is a thoughtful touch — shows the authors actually understand the workflow.”
“This is a niche tool for a niche user (heavy Claude Code power users) and the session log format Anthropic uses is undocumented and could change at any update. Tying workflows to internal log parsing is fragile infrastructure — treat it as a convenience, not a dependency.”
“At v0.5.18 this is still early software and the docs are sparse. libkrun has its own surface area of bugs, and running microVMs at agent-loop speed on macOS introduces a whole class of Apple Hypervisor Framework edge cases. I'd wait for v1.0 and a production case study before betting real workloads on this.”
“Agent observability tooling built by the community, not the vendor, is how this ecosystem will mature. Ferretlog is primitive but it points at a real gap: we need git-style versioning and auditability for agent sessions, not just for code.”
“Every autonomous agent that executes code needs a proper sandbox — not a polite request for the agent to be careful. smolvm represents the infrastructure layer that makes truly autonomous code execution safe enough to deploy at scale. This kind of primitive is foundational for the agentic software era.”
“Terminal-only, Claude Code-specific, no visuals — this tool exists entirely outside my workflow. The underlying insight (session replay and cost tracking) is useful, but it needs a UI before it reaches anyone outside the developer community.”
“For anyone building AI tools that touch code, smolvm means you can let your AI actually run things without fear. That unlocks a whole category of 'show me the output' UX patterns that weren't safe before. Less time explaining sandboxing to users, more time shipping features.”
Weekly AI Tool Verdicts
Get the next comparison in your inbox
New AI tools ship daily. We compare them before you waste an afternoon.