The verdict on every category, and the scores behind it.
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.
Already a member? Log in
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.
Connect B4 to your AI tools
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. Start a stack review or diligence pass with independently researched category scores, then test the recommendations against your scope, costs, and capacity to operate the systems.
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. See a complete scorecard →
03
11,031 vendor files
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 how far AI has come in each part of the software market. 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. Server URL and config →
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
Technology leaders
Walk into planning with a researched starting point for each decision in 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.
Investors
Underwrite the category the company lives in.
B4 scores the category a target company lives in on strategic differentiation and AI feasibility, so you can tell a real moat from one AI is about to erase. The Continuum shows where the category is heading before it shows up in the metrics.
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.
See plansAlready a member? Log in
Not buying yet? Get the free Build Report — a taste of the verdicts, no purchase needed. (Buying a plan adds you automatically.)