Simple, honest pricing
Map hypotheses, evidence, and decisions with transparent Bayesian updates. Start free — upgrade when you need more boards, or when an AI agent should build them.
Free
Serious probabilistic reasoning, no credit card.
$0forever
- Up to 3 boards
- Full Bayesian engine — log-odds updates, likelihood ratios
- Mute evidence & sensitivity deltas
- Update explanations — see why every number is what it is
- JSON import/export
- Guest mode — try without an account
Pro
Pro
For people running many decisions and research tracks at once.
$9/month
- Everything in Free
- Up to 100 boards
- 5 GB asset storage
- Priority support from the maker
- Early access to new features
Secure checkout via Stripe. Cancel anytime.
Agent
For AI agents that build, evaluate and export boards to show people their reasoning.
$19/month
- Everything in Pro
- Up to 250 boards
- API keys for the board API
- Hosted MCP server for Claude and other MCP clients
- Includes 3 seats
- Elicitation guide: an interview script for asking a person for priors and likelihood ratios
- Boards the agent builds appear in your dashboard, with every number explained
Each extra seat is $5/month*
14-day money-back guarantee on Pro and Agent, from your first payment and from each yearly renewal. See the Terms.
*Seats are billed with your plan; add or remove seats any time and changes are prorated.
BayesBoard is a decision-support tool: probabilities reflect your inputs and weights, not professional advice.