Startup idea: Resurfacing Engine for Forgotten Hub Notes
Users link notes to hub ideas like [[Psychology]], but hubs quietly pile up dozens of links and are never revisited to see what has accumulated.
Get the PRD prompt, $9.99 Market: $45K in 3 years
r/ObsidianMD · Sep 14, 2026 – Oct 14, 2026 · 22 upvotes
How do you keep track of recurring ideas in your…
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Resurfacing Engine for Forgotten Hub Notes is a startup idea for Obsidian users. Users link notes to hub ideas like [[Psychology]], but hubs quietly pile up dozens of links and are never revisited to see what has accumulated. A thread in r/ObsidianMD drew 22 upvotes and 11 comments between Sep 14, 2026 – Oct 14, 2026. People get by with Smart Connections and Spaced Repetition plugin, and that still leaves this job open. Hotness is 2.45, Cool. Mild annoyance. Price-sensitive audience. The thread drew 22 upvotes and 11 comments. Gaps in existing tools. A 1-2 week mvp. A first version is weekend-easy, about 1 week, priced under $10 a month and charged as a one-time purchase. The pain, the source, the alternatives, the scope notes, and the questions on this page are free to read and free to build from. The agent starter prompt is the paid part. The first slice is on the page. One credit unlocks the rest, to paste into a coding agent, download as Markdown, or send as a private link.
Who has it
Obsidian users.
- Obsidian users
- B2C
- Global
- r/ObsidianMD
What people use now
2 options, and the gap between them.
Smart Connections
Spaced Repetition plugin
Real gaps in the existing tools.
Resurfacing Engine for Forgotten Hub Notes is built for the part these leave undone.
A way through
A plugin that uses spaced repetition to periodically surface hub notes with the most new connections, prompting a review.
MVP scope
The first version, in 1 week.
- 00 Goal
The one job
Spaced-repetition nudges that bring back the hub notes gaining the most new links.
- 01 Day 1
The core
Find the hub notes with the most new connections.
- 02 Days 2–3
The follow-through
Resurface them on a spaced-repetition schedule, prompting a review.
- 03 Days 4–5
How it ships
As a plugin inside the tool people already work in. AI helps, but the core job works without it.
- — Not in v1
Left out on purpose
Replacing Smart Connections. Version one does the one job above and stops there.
How it could charge
The business model, at a glance.
- Model
- One-time purchase
- Price
- Under $10 a month
- Buyer
- PeopleAn individual or household pays
- Region
- Global
Hotness
Why it scores 2.45.
Mild annoyance. Price-sensitive audience. The thread drew 22 upvotes and 11 comments. Gaps in existing tools. A 1-2 week mvp.
22 upvotes 11 comments r/ObsidianMD Sep 14, 2026 – Oct 14, 2026 verified Oct 14, 2026 Thread ↗
Weights: pain 25%, willingness to pay 20%, demand 20%, gap 15%, ease 10%, recency 10%. Recency is recomputed every build. The source report’s 1–10 score is not shown.
Market size · estimate
How big this could get
A bottom-up estimate for Resurfacing Engine for Forgotten Hub Notes: real customer counts × a realistic price. Not a forecast.
$4.5M
300,000 users · 10% of Obsidian users worldwide (low end of public estimates)
$2.3M
150,000 users · the community plugin directory
$45K
3,000 users · 2% of the reachable segment in three years
What that means
3,000 users at $15 = $45K in sales
Low confidenceHow we estimated this
- Base: 3,000,000 Obsidian users worldwide (low end of public estimates).
- Has the problem: 10% (assume 1 in 10 have a large enough vault).
- Revenue per user: $15 one-time ($15 one-time).
- Reachable: 50% (the community plugin directory).
- Three-year capture: 2% of the reachable segment.
TAM = customers with the problem × revenue per customer. SAM = the part an early product can reach. SOM = a conservative three-year share of SAM. Bars use a log scale. Shares marked “assume” are our judgment, not measured.
Source: No official count; public estimates range 3–10M (CEO Steph Ango, 2025)
Take it to a build
Build Resurfacing Engine for Forgotten Hub Notes with an agent, or with us.
Agent starter prompt
$9.99 / 1 credit
A full PRD written for a coding agent: scope, data model, screens, edge cases, and the first week of tasks for this idea.
- Copy it straight into Claude Code, Cursor, or Codex.
- Download it as a .md file you keep.
- Send your bot a private link that refreshes every seven days.
# Agent starter prompt: Resurfacing Engine for Forgotten Hub Notes You are a senior product engineer. Build only the product described in this document. If a detail is missing, choose the smallest option and write it down in the README. Do not invent a second product, a marketplace of marketplaces, or a growth hack. ## Product Name: Resurfacing Engine for Forgotten Hub Notes One line: Spaced-repetition nudges that bring back the hub notes gaining the most new links. Shape: Plugin AI stance: AI-assisted Region for v1: Global Hotness (context only, not a requirement): 2.45 (cool). Mild annoyance; price-sensitive audience; thread engagement 22▲/11💬 (demand 1/5); gaps in existing tools; a 1-2 week mvp. ## Problem Users link notes to hub ideas like [[Psychology]], but hubs quietly pile up dozens of links and are never revisited to see what has accumulated. Who feels it: Obsidian users.
The first slice is above. The rest unlocks for 1 credit and is never in this page’s HTML.
Credits work on both sites. On Business Ideas to Build the same credit unlocks the business plan and growth playbook for Resurfacing Engine for Forgotten Hub Notes.
Or we build it
Your first version, shipped by our team.
A working product in your repo, built from this PRD. You own the code.
$1,000 scoping fee, credited toward the build.
Equity instead of cash is an application, not a checkout →Questions
Is this idea already taken?
People already use Smart Connections, Spaced Repetition plugin. Those options do not do the job in the solution above. The idea is free to build. Nothing here is an exclusive claim.
How hard is a first version?
Weekend-easy. A tight MVP is about 1 weeks (1 week), assuming the regulated or partner-gated parts are stubbed. The paid prompt turns that into tasks.
Who would pay, and how?
The audience is Obsidian users. Charge a one-time purchase, and test a price under $10 a month. Willingness to pay is one input to Hotness, not a promise that someone will buy.
Can I use the evidence?
Yes. Build the product. The thread title is a short excerpt with a link, not a quote we are putting in someone's mouth. Exact post dates and verbatim lines are added only after a manual check. Ideas are suggestions, not medical, legal, or financial advice.
A business write-up of this idea, with its market size, sits on the sister site. Get the business-plan prompt