The Index shows you how to think. A plan tells you what to do.
The public Index lays out how to reason about building versus buying any of 1,603 software categories. A plan gives you the answer: the call, the numbers behind it, the full vendor field, and a live feed as the market moves.
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Public · free
How to think
The framework. Two axes, four calls, five dimensions.
The directory. 1,603 categories you can search.
The considerations. The build case and the buy case on each.
B4 Web · $49/mo · B4 Agent · $199/mo
What to do
→ The verdict. Build, Buy, Bridge, or Beware.
→ The numbers. The scorecard, the vendors, the pricing.
→ The trajectory. Where it's heading, live, via the Continuum and MCP.
Made for your AI stack
You bring the AI. B4 brings the judgment.
B4 is the decision layer your own AI tools pull from. Connect the MCP and your agents query the verdict, the scorecard, and the vendor field directly — and when you want the dashboard view, the Cockpit holds your watchlist, stack audits, and exports. A stack review or a diligence pass that used to take an analyst a week runs in a few minutes, grounded in an independently researched score that stays current with the market.
What a plan gives you
01
The verdict
Build, Buy, Bridge, or Beware on every one of the 1,603 categories. The call the public Index holds back.
02
The 5-dimension scorecard
Specificity, AI feasibility, vendor value, strategic control, and cost trajectory, each scored 1 to 5 with the reasoning behind it.
03
22K vendors, with pricing
The full vendor field for each category, with pricing and positioning, well past the two names everyone else sees.
04
The Continuum
A live, longitudinal read on AI's progression across the software landscape. Where the ground is moving, how fast, and what to do about it. See the public log →
05
A live MCP server
Query the Index from Claude or your own tools. Re-scores flow straight in, so your agents always get the current call, not a stale export.
06
API, SDK, and export
Pipe B4 into your stack to make it a part of your decision matrix. The whole index exports to CSV and JSON whenever you need it.
Built for the people making the call
Priority use case
Venture capital and investors
Underwrite the category, not just the company.
Before you wire the money, see how defensible the position really is. B4 scores the category a target SaaS company, or a raw idea, lives in on strategic differentiation and AI feasibility, so you can tell a real moat from one AI is about to erase. Use it to pressure-test whether a company is worth investing in, or to gut-check an idea before it ever raises. The Continuum shows you where the category is heading before it shows up in the metrics.
Technology leaders
Walk into planning with the call already made on your stack.
Rationalize a sprawling application stack against an independent score instead of vendor decks or vendor-paid scoring systems. The verdict, the scorecard, and the vendor field give you a defensible position on keep, prune, build, or bridge for every line item.
Executives and operators
A new tool for negotiation.
Know which tools earn their keep, which AI has quietly made optional, and which deserve real investment. The reasoning is there to defend the decision to a board or a budget owner.
Get the call on every category
From $49/month for the whole index in your browser, $199/month to put it inside your agents. Every verdict, the five-dimension scorecard, full vendor pricing, the Continuum, and a live MCP. Cancel anytime.
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Not buying yet? Get the free Build Report — a taste of the verdicts, no purchase needed. (Buying a plan adds you automatically.)