Billing¶
Understand Functional AI's billing system, subscription tiers, and usage management.
Billing Model¶
Functional AI uses a dual billing model:
- Subscription Tiers
- Monthly subscription providing message quota, storage limits, and feature access
- Pay-As-You-Go (Medium & Pro)
- Optional overflow charges at $0.10/message when you exceed your monthly tier limit
Subscription Tiers¶
| Tier | Messages | Starting Price |
|---|---|---|
| Basic (free trial) | 100 lifetime (no recurring reset) | Free |
| Medium | 400/month | $24.99/mo |
| Pro | 1,500/month | $99.99/mo |
All users start on Basic (free 100-message trial)
No subscription purchase required to get started. Once you've used your 100 lifetime messages, upgrade to Medium or Pro to continue.
See Subscription Tiers for complete comparison.
Quick Navigation¶
| Guide | Description |
|---|---|
| Subscription Tiers | Compare tier features and limits |
| Usage Limits | Understand your quotas |
| Overflow Handling | Configure over-limit behavior |
| Managing Subscription | Upgrade, downgrade, billing |
Checking Your Usage¶
- Go to Account in the sidebar
- View usage dashboard showing current vs. limits
- Monitor days remaining in billing cycle
Key Concepts¶
Monthly Message Quota¶
- What Counts
- Each successful AI response = 1 message (regardless of length or model)
- What Doesn't Count
- User messages, failed requests, or refunded errors
- Reset Schedule
- Billing cycle date (Medium and Pro subscriptions). Basic does NOT reset — the 100-message allowance is lifetime per account.
Messages don't roll over (Medium/Pro)
Unused messages reset each cycle on paid plans. Basic users have a one-time 100-message budget — use it to evaluate, then upgrade.
Overflow Handling¶
When you exceed your quota, choose how to respond:
STOP Mode - Messages blocked until quota resets (Medium/Pro) or you upgrade (Basic). Only mode available on Basic.
AUTO_PAY Mode (Medium and Pro only) - Automatically charge $0.10/message from your account balance
How overflow charges work
Unified Rate: $0.10 per message on Medium and Pro. Basic cannot top up — it's evaluation-only.
Process:
- You exceed monthly quota
- System checks account balance (needs ≥ $0.10)
- Message processes if balance sufficient
- $0.10 deducted immediately
- Service stops if balance reaches $0
Balance Sources: Top-up purchases, promotional credits, or refunds
Balance Management: Never expires, visible in dashboard, refundable (minus used overflow)
See Overflow Handling for configuration.
Billing Providers¶
For: Direct website signups
Features:
- Subscription management via customer portal
- One-time top-ups ($2, $5, $10, $20)
- Prorated billing on upgrades
- Credit/debit card payments
- Separate invoices and receipts
For: Shopify app users
Features:
- Managed via Shopify admin
- Consolidated billing with Shopify account
- Usage charges for top-ups
- Follows Shopify billing policies
- Merged invoices
Both providers offer identical tier limits and features.
Common Questions¶
When does my quota reset?
Medium/Pro: Billing cycle date | Basic: Never — 100 messages is a one-time lifetime allowance
What happens at my limit?
Basic: Sending stops permanently — upgrade to continue | Medium/Pro STOP mode: Messages blocked until next cycle | Medium/Pro AUTO_PAY mode: $0.10/message from balance
Can I upgrade mid-cycle?
Yes, takes effect immediately with prorated charges (LemonSqueezy) or per Shopify policies
Can I downgrade?
Yes, takes effect at next billing cycle
Getting Started¶
- Start on Basic — 100 free messages, no card required
- Use them to evaluate end-to-end fit
- Monitor usage in dashboard
- Upgrade to Medium or Pro before your trial allowance runs out