Validate an idea before you build it
You have an idea and a free weekend. Before you spend it, you want proof that strangers already want this, not a hunch from one Reddit thread you half remember.
Free plan: 10 requests a day, no card.
Is anyone asking for a self-hosted Calendly? How many in the last 90 days, and where?
demand_evidence"self-hosted Calendly", 90 days 38 asks · not thinfind_asksstrongest 5, with reasons 5 threadsfind_communitieswhere the asks cluster 6 communities
r/selfhosted Anyone found a decent self-hosted Calendly? Cal.com is too heavy for one person.
Hacker News Ask HN: Lightweight scheduling link I can run on a $5 VPS?- r/indiehackers Cancelled Calendly at $16/seat. Back to emailing times like a caveman.
Read-only. Sources cited. Nothing posted.
An evening of tabs.
- Open twelve tabs of Reddit search, which ignores half your words and sorts by nothing useful.
- Skim threads, mentally tally the ones that sound like real asks, lose count around the fourth subreddit.
- Decide based on the two threads you remember best, usually the two that agreed with you.
Three prompts.
- One prompt. Your agent picks the communities, searches all four sources, and classifies every thread.
- A count you can trust, the five strongest asks with permalinks, and an honest flag when demand is thin.
- Two follow-up prompts to read what people tried and where they gather. Done before the coffee is cold.
A real session, prompt by prompt.
Each step is one request. The whole session fits inside a Free day.
- 1
Ask the blunt question
You want a number and a cluster before you want detail. If the number is small, you stop here and you have lost ten minutes, not a weekend.
YouIs anyone asking for a self-hosted Calendly? How many in the last 90 days, and where?
Comes back38 asks across 6 communities in 90 days, clustered in r/selfhosted and Hacker News. The five strongest, each with a permalink and the reason it was counted as an ask rather than a mention.
- 2
Read what they already tried
The rejected alternatives are your spec. "Too heavy" tells you the wedge is a single binary, not a feature list.
YouFor those asks, what did people try, and why did it not stick?
Comes backCal.com comes up in 22 of 38 threads, almost always as too heavy for one person. Price is the trigger in a third of them. Two threads mention a cron-and-ICS hack that broke on timezone changes.
- 3
Find where they gather, and whether you can post
Demand you cannot reach is not demand. Knowing the launch path on day zero changes what you build first.
YouWhich communities do these asks come from, how big are they, and do any allow a launch post?
Comes backSix communities ranked by ask count, with member counts, a rules summary, and a promo-tolerance flag. r/selfhosted allows launch posts with a source link. Hacker News is Show HN.
- 4
Compare it against the other idea
The comparison is the answer more often than the absolute number. Three ideas cost three requests.
YouRun the same check for "self-hosted Cal.com alternative" and "open-source booking page" and compare.
Comes backA three-row table: asks, communities, top rejected alternative, thin-or-not. The phrasing with the most real asks wins, and it is usually not the one you started with.
What the numbers mean.
- You ask
- “Is anyone asking for a self-hosted Calendly? How many in the last 90 days, and where?”
- You get
- 38 asks in 90 days across 6 communities, clustering in r/selfhosted and Hacker News. Not thin. Most mention Cal.com as too heavy and price as the trigger.
An ask is not a mention
Reddibee counts "anyone found a lightweight Calendly?" and ignores "I use Calendly". A count of 38 means 38 people wanting something, not 38 threads that contain the word. The classification reason is on every item, so you can disagree with it.
Thin is a real answer
Under roughly ten asks in 90 days, spread across many communities, the tool says so. Thin does not mean dead. It means Reddit is not where these buyers talk, or the pain is not yet named. Both are worth knowing before you build.
Clusters beat totals
Thirty asks in one community is a launchable niche. Thirty spread over twenty communities is background noise. Look at the cluster before the count.
Run it for three ideas in one call. The tool takes a list, and the comparison is usually the answer.
The tools your agent picks.
You never call these by name. The agent reads the prompt and chooses. Listed so you know what is happening.
demand_evidence- Searches every source for asks about an idea, classifies each thread, returns a count, the strongest examples, and a thin flag.
find_asks- Newest-first list of threads where someone asks for a tool, an alternative, or help with a problem, filtered by community or keyword.
find_communities- Ranks communities for a topic with size, activity, a rules summary, and whether promotion is tolerated.
get_thread- Fetches one thread with its comment tree, each comment classified, so the agent can quote what people actually tried.
Copy, swap the brackets, paste into your agent.
Is anyone asking for a self-hosted Calendly? How many in the last 90 days, and where?
Compare demand for these three ideas over 90 days and tell me which has the strongest, most concentrated asks: [idea A], [idea B], [idea C].
For asks about [idea], what did people try already and why did it fail them?
Show me only asks where someone says what they currently pay. Quote the price.
Which communities produce the most asks for [idea], and which allow a launch post?
Is demand for [idea] growing or shrinking? Compare the last 30 days with the 30 before.
Honest limits.
- Reddit and Hacker News skew technical. If your buyer is a dentist or a florist, the signal here is thin and that is about the source, not the idea.
- Counts are as good as the classification. It is right most of the time and shows its reasoning, but it will occasionally count a rant as an ask. Read the top five yourself.
- Ninety days of history is the default. Older threads exist but are backfilled on demand, so the first check on an obscure niche can take a minute.
Asked before the first request.
How many requests does a validation take?
One for the count, one to read what people tried, one for communities. Three requests. On the Free plan you can validate three ideas a day.
Does it search X and Product Hunt too?
Yes. X is where devtool asks show up first, and Product Hunt shows you who launched into the same demand and how their comments went.
Can I trust a count of 38?
Treat it as 38 people who typed a request in public, with a link to each. It is not market size. It is proof that the pain is named and where it is named.
What if the tool says demand is thin?
Believe it, then try two other phrasings. People rarely ask for your product by your name for it. If all three are thin, Reddit is not your channel, and you have learned that in ten minutes.