Full-stack and AI engineer. I build open-source tools that make coding agents (Claude Code, Codex, Cursor) finish what they start, remember what they learn and spend less. More at nirfeinste.in.
Choose a job, then try the tool. Free and paid parts are described beside each link.
| Product | Start here |
|---|---|
| Betterloop | Paste a website URL for a free check, with no signup. Ongoing monitoring has Free and Pro plans. |
| Plainer | Explore a workspace for notes, files and planning. Notes and planning are free; the signed-in assistant has an optional Pro allowance. |
| Modurobot | Try a robot in a free 3D simulation, then compare parts with the SO-101 buying worksheet. Parts links may earn me an affiliate commission. |
| KeepFinding | Save a link or import bookmarks into a free read-later library. Try it in this browser; sign in to sync across devices. |
| MyFeed | Read a free topic feed or create one about something you care about. Optional email digests. |
| Gramfix | Correct selected text in compatible Mac apps with a shortcut. Apple Silicon; limited included corrections or your own OpenAI key. |
| WebSkins | Give websites a different look with an AI-powered Chrome extension. The public Store version requires your own Anthropic key. |
| AI Your Work | Start a free guided assessment of useful automations for your business, on the website or Telegram. |
| Human in da Loop | Let an AI agent ask your team for help. Start with the free software's setup guide; hosting and provider costs are your own. Paid worker jobs are not live. |
| OpenWorld | Play a free 3D browser game and change it with words. AI edits use limited included credit when available, or your own provider-billed key. (Source) |
| VidGen Studio | Turn a story into a free 3D storyboard, then film scenes with AI. Generated video, images and narration use prepaid credit. |
These are concepts to explore, not products available to order.
| Concept | Explore |
|---|---|
| Small Living | A modular electric-camper concept in 3D. |
| Nested Blocks | A modular-furniture concept that starts with a conversation. |
Hired in 60: start with six short, visual developer interview-prep lessons, then explore the YouTube channel. Also on Instagram and TikTok; those platforms may ask you to sign in.
| Project | What it does | |
|---|---|---|
| most-capable-agent-system-prompt | A copy-paste system prompt that has your coding agent build a self-improving agent system for any computer work |  |
| agent-harness | Skills, rules and hooks that make Claude Code or Codex act as a product team, a CEO or a portfolio manager |  |
| frugal | Your agent finds free tiers, programs, verified promo codes and cheaper alternatives before it pays for anything |  |
| flipback | An automatic /goal for every turn: sends Claude Code back when it stops before the work is done |
 |
| recall | Your Claude Code memory in every agent: Codex, Cursor and others read and write it over MCP |  |
| conductor | Verified, retried and fallback-backed commands for Claude Code, served as MCP tools |  |
| account-access | Scoped, resumable account access for coding agents, with OAuth renewal |  |
| mac-keepawake | Keep your Mac awake with the lid closed, and dim the backlight while it's shut |  |
| handy-ai | Android assistant that completes tasks on your phone: it taps, types and follows through |  |
| regressguard | Self-hosted CI eval harness for prompt regression testing (Docker + CLI) |  |
| standup | Writes your standup update from your git commits, in one command |  |
If one of these saves you time or money, a star helps other people find it.