Gross margin by customer
- Example customer A81.8%
- Example customer B-41.4%
- Example customer C47.5%
- Example customer D24.1%
Margin Guard for AI SaaS
Protect your AI SaaS margins.See every leak before it becomes a loss.
Connect Stripe, send your AI usage events, and PrinVox shows which customers, plans and features make money — and which quietly lose it.
Try free for 14 days — no card required
- Reads Stripe revenue — never moves money
- Deterministic margin maths
- Incomplete data is flagged, never hidden
Product
Which customers actually pay for themselves?
Revenue from Stripe, minus AI cost from your usage events, per customer. Negative rows are visible at a glance.
Demo data — not real customers| Customer | Plan | Revenue | AI cost | Gross profit | Margin | Status |
|---|---|---|---|---|---|---|
| Example customer A | Pro plan | $99 | $18 | $81 | 81.8% | Healthy |
| Example customer B | Starter plan | $29 | $41 | -$12 | -41.4% | Unprofitable |
| Example customer C | Pro plan | $99 | $52 | $47 | 47.5% | Healthy |
| Example customer D | Starter plan | $29 | $22 | $7 | 24.1% | Low margin |
Core margin intelligence
One honest number per customer, plan and feature
Every view comes from the same deterministic engine, so the totals always add up.
Demo dataFind the plan that loses money
Plan-level margin, so pricing problems show up before they hurt.
| Plan | Revenue | Margin |
|---|---|---|
| Pro plan | $198 | 64.6% |
| Starter plan | $58 | -8.6% |
Below zero margin: Starter plan
See which AI features cost the most
Cost only — revenue cannot be attributed per feature, so we do not pretend to.
Revenue · AI cost · Margin
Revenue minus AI cost is the margin you can trust
Cost that cannot be tied to a customer stays visible as its own line instead of disappearing.
Demo dataRevenue$256
AI cost$139
Gross profit$117
45.7%of revenue is left after AI cost
Unattributed: $6 · Last 30 days · demo
Leak detection
Alerts before margin turns into a loss
Account-level alerts for the selected period.
Negative margin
AI cost exceeds revenue for a customer in the selected window.
Margin drop
Gross margin fell compared with the previous period.
AI cost spike
AI cost rose sharply against its recent baseline.
High unattributed cost
A large share of AI cost is not tied to any customer.
Incomplete data
Some usage has unknown cost or an unsupported currency, so the margin is not final.
How it works
From billing and usage to margin
Four steps, all computed from your own connected data.
Stripe + AI usage events
Revenue read from Stripe. Usage events sent from your backend.
Attribution
Each usage event is tied to a customer and feature. Anything that cannot be tied is kept visible as unattributed.
Margin engine
Deterministic calculation: gross profit is revenue minus AI cost, margin is profit divided by revenue.
Profitability views
Margin per customer and plan, AI cost per feature, and alerts when margin turns risky.
AI agents · MCP
Let your AI agents read your margins
PrinVox runs a remote MCP server. Connect an MCP-compatible agent with scoped OAuth access, ask about margins in plain language, and decide exactly what it may do.
Early access- Stripe + AI usageRevenue and usage events
- PrinVox Margin GuardDeterministic margin engine
- Remote MCPOAuth sign-in · scoped tools
- Your AI agentse.g. Claude or ChatGPT, where MCP connectors are supported
› Which customers have a negative margin?
list_negative_margin_customers
Example customer B-41.4%
AI cost exceeds revenue for this customer in the selected window.
Scoped access
You approve each scope when connecting. Write scopes are off by default.
Read tools
13 read-only tools for overview, customers, plans, features, alerts and reports.
Controlled write actions
Acknowledge or resolve alerts and manage ingestion keys — only with the matching scope. Key actions need explicit confirmation.
Revoke anytime
Disconnect an agent in one click. Access ends immediately.
Audit log
Every tool call is recorded: started, succeeded, replayed or denied.
Tenant isolation
An agent only ever sees the account that granted access.
Connections
What connects, and how
Honest about the architecture: usage is sent by you, not pulled from provider accounts.
Stripe
Reads revenue onlyConnect via Stripe Connect to read customer revenue. PrinVox initiates no payments, payouts, transfers or refunds. PrinVox requests Stripe’s standard Connect permission (scope read_write; Stripe offers a read-only scope only to Stripe Apps).
OpenAI API usage
Usage eventsSend events with model and token counts from your backend. No OpenAI account sync.
Anthropic API usage
Usage eventsSend events with model and token counts from your backend. No Anthropic account sync.
Google Gemini API usage
Usage eventsSend events with model and token counts from your backend. No Google account sync.
Security
Built to be checked, not just believed
Facts about how the product works.
Tenant isolation
Each account only ever sees its own data.
Sealed credentials
Provider credentials are encrypted before storage.
Verified Stripe webhooks
Webhook signatures are verified and processed idempotently.
Revenue read only
PrinVox only reads customer revenue from Stripe and initiates no money movements.
Deterministic maths
The same inputs always give the same margin.
Auditable attribution
Every cost can be traced to the events behind it.
Pricing
Simple monthly pricing
Every plan includes Stripe revenue, AI usage ingestion, margin views and alerts.
Basic
$29 per month
For solo founders getting their first real margin number.
- 1 Stripe connection
- Up to 25 tracked customers
- Margin by customer and plan, AI cost by feature
- Margin alerts
- 30-day usage history
Standard
$79 per month
For small teams tracking margin by plan and customer.
- 1 Stripe connection
- Up to 200 tracked customers
- Margin by customer and plan, AI cost by feature
- Margin alerts
- 12-month usage history
Premium
$199 per month
For growing AI SaaS teams that need the full picture.
- 1 Stripe connection
- Unlimited tracked customers
- Margin by customer and plan, AI cost by feature
- Margin alerts
- Full usage history
Try free for 14 days — no card required. The trial only starts when you start it in the app. It includes the Basic plan’s features (up to 25 tracked customers), at most 5,000 usage events in total and 60 per minute. It ends by itself — no charge and no automatic conversion into a subscription.
Higher plans raise the customer limit and history.
All plans are billed monthly through Stripe. You can cancel anytime. Per § 19 UStG (German small-business rule), no VAT is shown separately.
Methodology
Methodology and FAQ
How the numbers are produced, and what happens when data is incomplete.
How is revenue read?
Through a Stripe Connect link that PrinVox uses only to read data. PrinVox requests Stripe’s standard Connect permission (scope read_write; Stripe offers a read-only scope only to Stripe Apps), yet its code only performs read requests and never initiates payments, payouts, transfers or refunds. Revenue is recognised per customer from Stripe invoices and payments, including refunds.
How is AI cost calculated?
From the usage events you send (model, input and output tokens), priced with pinned model pricing. Cost is never guessed: if pricing is unknown the cost is flagged rather than shown as zero.
How does attribution work?
Each event carries a customer reference and a feature key. PrinVox ties the cost to that customer and feature.
What does UNATTRIBUTED mean?
AI cost with no usable customer reference. It is shown separately so it never silently disappears or is spread across customers.
What if data is incomplete?
The affected number is marked as partial or needing review instead of being presented as final. A gap is never turned into a clean zero.
What is the difference between an event with unknown cost and an event that was never sent?
If an event WAS sent to PrinVox but its model price is unknown, PrinVox has the event and marks the affected cost and margin as incomplete instead of showing a clean number. If an event was NEVER sent, PrinVox cannot know it happened, so it cannot be flagged and is missing from the results. Complete, reliable ingestion from your backend is therefore your side of the measurement.
Does it connect to OpenAI, Anthropic or Google Gemini directly?
No. You send usage events from your own backend; there is no sync with provider accounts.
Know your real AI margin.
Connect Stripe, send your first usage event, and see which customers pay for themselves.
Connect your AI SaaSTry free for 14 days — no card required