The Spark · three plays every Sunday

Most ideas aren’t worth building. Find the one that is.

You've got more ideas than time — or one you can't tell is real. Sparkfile is how you find the one worth building and kill the rest before they cost you a season, then run it: no team to hire, no app to buy, just you and Claude.

Or run your idea through the filter, free →

The flagship

Find the idea worth building.

Drop in an idea — or three — and Sparkfile runs each one through four honest gates: real demand, a real wedge, a cheap way to validate it, and whether you can actually build and run it yourself. Most ideas don't survive. That's the point: you find the one that does in an afternoon instead of a lost quarter. Free to try, and it runs in your own Claude — nothing to install.

Run your idea through the filter →

Then run it

Kept the idea? Hire the team.

Once you've found the one worth building, the free 90-day roadmap takes you from an empty folder to a running business: three AI cofounders — Growth, Ops, Brand — that you direct as CEO, on Claude alone. A Claude Code path for people who've never opened a terminal, and a chat-only track you can start today. Find it, then run it.

See the 90-day roadmap →

The live run

All entries →

Jul 15, 2026

Shopify said yes.

Seventh build log. Two days after I wrote about submitting Kōkua and not knowing if it'd get approved, Shopify approved it. It's live on the App Store.

Who it's for

You've got a folder of ideas and no honest way to choose — or you've already picked the thing and you're doing every job yourself: the spec at midnight, the proposal, next week's schedule. Sparkfile is for both ends of that. Find the idea worth building, then run it without hiring a team you can't afford. Written by someone who's done the jobs, not someone selling a future.

The difference

Claude only. No app in the middle.

You don't need an orchestration layer, a drawer of third-party agents, or one more SaaS wrapper. The filter runs in your Claude. The team is memory files and prompts you own. Everything here runs on Claude's own tools — Chat, Cowork, Claude Code — because that's already the whole stack. A wrapper would just put a tollbooth between you and the thing that does the work.

From the library

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FoundationsWORKFLOWHANDS-ONStart Here

Validate demand before you build

Pull real search-demand signal for your idea, its category, and a competitor — programmatically, no screenshots — and get a plain read on whether interest is growing or dying before you commit a week to building.

Jul 10, 2026 · 20 min

FoundationsWORKFLOWSTART HEREStart Here

Run the idea filter before you hire the team

Four gates and two human checks that turn 'should I build this' into a verdict (Keep, Bench, or Scrap) before you write a single role file.

Jul 4, 2026 · 45 min

FoundationsCOMPARISONHANDS-ONBuilding the Product

Claude Code vs. Cursor for a non-engineer founder

Cursor is a full code editor with AI built in; Claude Code is conversation-and-diff-first with no editor to learn. The right pick depends on whether you want to live in an IDE or not.

Jul 1, 2026 · 4 min

FoundationsCOMPARISONHANDS-ONWorking with Claude

Cowork vs. no-code builders

No-code builders are for structured, persistent apps with a defined data model. Cowork is for conversational, judgment-heavy workflows. Most founders need both, for different jobs.

Jul 1, 2026 · 3 min

FoundationsCOMPARISONSTART HEREWorking with Claude

Free vs. paid Claude: what's actually worth paying for

A framework for deciding whether to pay, since exact plans and prices change: usage volume, whether you need Cowork or Claude Code, and how much context you regularly need in one conversation.

Jul 1, 2026 · 3 min

The operator

25 years building audio products and companies: Grace Design, HeadRoom, now Warren Labs. These days I ship real products by directing Claude instead of hand-writing every line — and I run every one through this same filter first. The most recent one it greenlit, Kōkua, a Shopify accessibility scanner, is now live on the Shopify App Store underKahakai LLC.

Read the full story →

The Spark

Three plays to run this week — every Sunday.

Read it in three minutes. Ship something by Friday.