The B4 Index
Your software decision engine.
Browse the categories for free. Every plan unlocks the full category and vendor database, and higher tiers hand your agents more powerful tools.
Billed once a year · 2 months free
Billed monthly · annual saves 2 months
B4 Web
For founders and consultants
The full Index in your browser. Every verdict, every vendor, for one person to read, search, and audit.
$98 less than paying monthly Cancel anytime
- Every verdict across 1,600+ categories, in your browser
- The five-dimension scorecard and the reasoning behind each score
- The full vendor field, all 22,000+ vendors with pricing
- Search, facets, and the org-size lens on every category
- Watchlist, saved views, and stack audits
- Browse and score categories and vendors over MCP, included free
B4 Agent
For teams and analysts
Everything in Web, plus the full Index over MCP, so your own AI queries the current call. Comes with the workflow tools and export.
$398 less than paying monthly Cancel anytime
- Everything in B4 Web
- Full MCP workflow tools: audit your stack, compare build vs. buy, get vendor recommendations
- Full vendor lists through MCP
- CSV and JSON export of the index
Enterprise
For agentic workflows
The whole Index over a REST API. Query it programmatically, in bulk, wired into how your team already works.
Quoted per contract
- Everything in B4 Agent
- Full REST API to query the whole index programmatically
- Bulk access and higher rate limits
- Onboarding scoped with your team
- Invoiced annually
The directory
The whole Index, one screen
A plan opens the live directory. All 1,600+ categories, each scored on five dimensions, filterable and searchable, sortable any way you want, and tuned to your own AI-maturity lens. This is the room you're buying a key to.
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Star your shortlist
Pin the categories you're weighing and pick up where you left off.
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Search the reasoning, not just names
One box across categories, vendors, and the rationale behind every call.
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Set your AI-maturity lens
Watch a build-or-buy call shift for a lean team versus an AI-mature one.
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Filter by the call
Jump straight to the Build, Buy, Bridge, or Beware categories.
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Filter by AI replacement type
Narrow to how AI is actually reshaping each category.
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Read the vendor field
See how many vendors compete before you commit, from one to a few hundred.
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Slice by function and domain
20 function groups and 169 domains, so you land in your corner fast.
Every row carries the five-dimension score behind the call: specificity, AI feasibility, vendor value, strategic control, and cost trajectory. Sort on any of them, save the view, and export it on B4 Agent.
A closer look
What you get when you open a category
The directory is the front door. Behind every row is the full case for the call.
Every category
The reasoning behind every call
Open a category and the whole argument is there: the verdict, the five-dimension scorecard, a written rationale for each score, and the full vendor field with real pricing. You see why the call is what it is, not just the label on it.
Confidence
See how close the call is
Every score is read one step either side of what it landed on. The arc shows the share of readings on each verdict, so a confident call and a coin-flip never look the same, and it shows where more AI maturity would tip the decision.
Free to read
A build-or-buy breakdown for every category
Each category has its own page laying build, buy, and bridge side by side: cost shape, time to value, the differentiation each path captures, and who it fits. These pages are free. A plan opens the live app on top, where you work the whole Index at once.
The free Index stays free
The framework, the public directory, and the rate-limited browse and score tools aren't on a trial clock. A plan buys the verdict, the numbers behind it, and the full vendor field.
Compare free and paid plans
| Capability | Free | B4 Web | B4 Agent | Enterprise |
|---|---|---|---|---|
| Public pages, email gate | Included | Included | Included | Included |
| Browse and score categories and vendors over MCP (rate-limited, capped vendor depth) | Included | Included | Included | Included |
| Live directory app with full vendor lists in your browser | Not included | Included | Included | Included |
| Watchlist, saved views, stack audit | Not included | Included | Included | Included |
| CSV / JSON export | Not included | Not included | Included | Included |
| MCP workflow tools: audit your stack, compare build vs. buy, get vendor recommendations | Not included | Not included | Included | Included |
| Full vendor lists over MCP | Not included | Not included | Included | Included |
| REST API and bulk access | Not included | Not included | Not included | Included |
Vendor depth on the free browse and score tools is capped for everyone; B4 Agent is what lifts the cap on the machine channel. Your stack stays yours. Watchlists, saved views, and audits are scoped to the account that created them, and are never shared or sold. See the privacy policy and subscriber terms.
Questions
What's the difference between B4 Web and B4 Agent?
Access mode. B4 Web is the full index for a person in a browser: every verdict, the scorecards, the full vendor field, search, and audits. B4 Agent keeps all of that and adds the index for your agents: the MCP workflow tools, full vendor lists over MCP, and CSV/JSON export. Web is for reading it yourself; Agent is for wiring it into your AI.
Is there a free version?
Yes, and it isn't a trial. Anyone can read the public pages and use the browse and score tools over MCP, rate-limited and with capped vendor depth. A plan lifts the caps and unlocks the full field, the workflow tools, and export.
What is MCP, and how does my AI use B4?
MCP is the open protocol AI clients use to call outside tools. B4 runs an MCP server, so your agent can browse and score categories, and on Agent, audit your stack, compare build vs. buy, and pull vendor recommendations, in the same session your agent is already working in. No copy-paste.
Can I use B4 inside Claude, ChatGPT, and Cursor?
Yes. Any MCP-capable client connects the same way: Claude, ChatGPT, Cursor, and others. The free browse and score tools work anywhere; the workflow tools and full vendor lists over MCP come with B4 Agent.
How current is the data?
Categories are scored daily as new funding, launches, and vendor moves land, and the index publishes on a quarterly cadence. You're always querying the current call, not a static snapshot.
Can I switch plans or cancel anytime?
Yes. Switch between Web and Agent in the Stripe billing portal from your cockpit, prorated, on the subscription you already have. Cancel there too; access runs to the end of the period you paid for and nothing renews.
How does annual billing work?
Annual is billed once, up front, and works out to 2 months free versus paying monthly, on either plan. You can start monthly and move to annual later from the portal.
What's included in Enterprise, and is there an API?
Enterprise adds a full REST API over the whole index to query it programmatically, in bulk, with higher rate limits, plus onboarding scoped to your team. It's quoted per contract and invoiced annually. Email to talk through what you need.
How many categories and vendors do you cover?
1,600+ independently scored categories and 22,000+ vendors with pricing, across the software your business actually buys. The counts track the live index, so they only grow.
What does “categories are scored, not vendors” mean?
The five-dimension score sits on the category (the build-vs-buy question, like “CRM” or “feature flags”), because that's the decision you're making. Vendors are the field inside a category, listed with pricing, not graded head-to-head.
Do you store or share my data?
Your watchlists, saved views, and stack audits are scoped to your account and aren't shared or sold. See the privacy policy and subscriber terms for the specifics.
What payment methods do you take, and do you offer refunds?
Checkout runs through Stripe and takes any card it supports. Cancel anytime and access runs to the end of your paid period. If something's wrong with a charge, email and we'll sort it out.
How billing works
Upgrading to Agent
Moving from Web to Agent turns on the MCP workflow tools and export for your own AI: the audit, compare, and recommend tools, full vendor lists over MCP, and CSV/JSON. It's a prorated switch in the Stripe billing portal from your cockpit; you keep the subscription you already have.
Cancelling
Cancel in the portal at any time. Access runs to the end of the period you paid for; nothing renews after that.
Annual terms
Annual is billed once, up front, and works out to 2 months free on either plan. Prices are USD and exclude any tax your jurisdiction adds at checkout.
Checkout is handled by Stripe and asks you to accept the subscriber terms before it takes a card. Already have an account? Log in, or manage an existing plan from the cockpit.