AI tool comparison
Ferretlog vs Pretty Fish
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
Pretty Fish
Free, beautiful Mermaid diagram editor that works offline
75%
Panel ship
—
Community
Free
Entry
Pretty Fish is a free, open-source Mermaid diagram editor with live preview, 5 built-in themes, multi-page workspaces, and one-click SVG/PNG export. It works offline as a Progressive Web App (PWA) and requires no account, no login, and no installation. It supports all 14+ Mermaid diagram types including flowcharts, sequence diagrams, Gantt charts, entity-relationship diagrams, and Git graphs. The editor includes syntax highlighting, auto-completion, instant error feedback, and a clean split-pane layout. The multi-page workspace lets you manage entire diagram projects in a single session. Export quality is excellent — SVG output is clean and scaling-ready for use in presentations, docs, or design systems. Pretty Fish hit Hacker News front page today with 128 points and has the makings of the go-to Mermaid editor for developers who generate diagrams from AI-assisted documentation workflows. With LLMs increasingly generating Mermaid syntax in their outputs, having a polished renderer and editor matters more than ever.
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.”
“The official Mermaid live editor is clunky and slow. Pretty Fish loads instantly, works offline, and the multi-page workspace means I can manage all my architecture diagrams in one place. Bookmarking this immediately as my default Mermaid editor.”
“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.”
“It's a genuinely nice editor but it's solving a niche problem — most devs who need Mermaid diagrams already use VS Code extensions or embed them in Notion. And with no backend, there's no collaboration or sharing story, which limits its use in team workflows.”
“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.”
“As AI tools increasingly output Mermaid syntax to explain architectures and flows, the need for a great rendering environment grows. Pretty Fish positions itself at the intersection of AI-generated diagrams and human editing — that's a well-timed niche.”
“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.”
“Five beautiful themes and clean SVG exports mean I can finally use Mermaid diagrams in client-facing presentations without them looking like developer scratch notes. This is the Mermaid editor I've always wanted and the zero-friction setup seals it.”
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