Billing & Usage
Gravity Rail uses a credit-based billing model. Everything your organization does — AI conversations, SMS messages, phone calls, and emails — draws from a shared credit pool. This guide explains how credits work, how to monitor your balance, and how to configure auto-reload and spending limits.
Billing settings live in two places:
| Location | Path | Who can access |
|---|---|---|
| Workspace billing | Settings → Billing (/w/{wid}/settings/billing) | Workspace admins |
| Organization billing | Organization settings → Billing tab | Org owners with billing access |
The Credit Model
How credits work
Credits are the unit of account for all usage-based resources:
Every credit costs a flat $0.01 — the same price whether it's included in your plan or bought as extra usage.
| Resource | Credits consumed |
|---|---|
| AI operations (chat messages, summaries, voice turns) | Varies by model and token count, scaled by your plan's AI discount |
| SMS | ~1.1 per segment (entry tier; lower at higher tiers) |
| Phone call | ~2 per minute (entry tier; lower at higher tiers) |
| 1 per message |
Credits are tracked at the organization level — all workspaces in your organization draw from the same pool. Workspace-level resource limits (number of members, sites, phone numbers, and inboxes) are separate plan caps and are not deducted from credits.
Commitment tiers
The credit price is always $0.01. Your organization's plan determines how many credits are included each period and how much your usage is discounted — higher tiers give you cheaper AI (a lower AI multiplier) and lower telephony rates:
| Plan | Monthly fee | Included credits | AI discount | Telephony rate |
|---|---|---|---|---|
| Pay as you go | $0 | 0 | — | standard |
| Pro | $200 | 20,000 | 25% off | reduced |
| Max | $1,000 | 100,000 | 50% off | reduced |
| Enterprise | $2,000 | 200,000 | 60% off | at cost |
Included credits reset monthly. Unused included credits expire at the end of each monthly window, including when the subscription is billed annually. Credits purchased through a manual top-up or auto-reload do not expire. Negotiated accounts can be set up with their own custom AI discount and telephony rates.
Credit enforcement
What happens when your organization's credit balance reaches zero depends on whether your organization uses hard enforcement or soft enforcement.
Hard enforcement (default for new organizations)
All organizations created on Gravity Rail use hard enforcement by default. When credits reach zero, Gravity Rail immediately suspends usage and returns an HTTP 402 error to any operation that would consume credits. Service resumes automatically once credits are replenished — either by auto-reload charging your payment method or by a manual top-up.
Soft enforcement (legacy organizations)
Organizations that existed before hard enforcement was introduced are grandfathered on soft enforcement. When credits reach zero, Gravity Rail sends an internal alert but does not immediately suspend service — operations continue while your team responds. Only an explicit usage suspension set by a Gravity Rail administrator hard-blocks operations on a soft-enforcement org.
Legacy organizations can be upgraded to hard enforcement at any time by a Gravity Rail administrator via the admin Organizations settings page.
Usage suspensions record why service was stopped. A suspension caused by credit exhaustion clears automatically after a funded refill. Operator and payment-collection suspensions remain in place until an administrator or successful payment resolution clears them, so a plan-credit reset cannot override an intentional control.
Viewing Your Balance and Usage
Workspace billing page
Go to Settings → Billing (/w/{wid}/settings/billing) to see:
- Current Plan tab — credits used and remaining for the current billing period, active subscription details, plan inclusions (member limit, sites, inboxes, phone numbers), and enabled features.
- Invoices tab — historical invoices for your workspace's subscription, with download links.
The credit stat at the top of the Current Plan tab shows your real-time balance. The progress bar turns red when usage exceeds 90% of the plan's included credits.
Organization billing tab
Organization owners with billing access can view the aggregate picture across all workspaces under Organization settings → Billing:
- Subscription overview — plan name, status, and billing period dates.
- Credit usage card — a progress bar showing credits consumed vs. total granted, the reset date, the remaining balance, and the overage credit price ($0.01).
- Workspace plans card — each workspace's subscription item, status, and links.
Auto-Reload
Auto-reload automatically purchases additional credits when your balance runs low, so usage is not interrupted even after your plan's included credits are exhausted.
Enabling auto-reload
- Go to Organization settings → Billing → Extra Usage.
- Toggle Enable extra usage on.
- Click Adjust auto-reload to set:
- Threshold — the credit balance at which a reload is triggered.
- Reload amount — how many credits (or dollars of credits) to purchase each time.
- Click Save.
When the balance drops to the threshold, Gravity Rail charges your payment method on file and immediately adds the purchased credits to your balance.
Buying credits manually
You can also purchase a one-time credit top-up without enabling auto-reload:
- Go to Organization settings → Billing → Extra Usage.
- Click Buy extra usage.
- Enter the amount and confirm the purchase.
Credits are applied immediately after the payment is processed.
Spending Limits
A monthly spend limit caps how much your organization can spend on extra usage (auto-reload and manual top-ups) in a UTC calendar month. This prevents runaway charges if usage spikes unexpectedly. The limit resets at 00:00 UTC on the first day of each month; it does not follow your subscription renewal date.
Setting a spend limit
- Go to Organization settings → Billing → Extra Usage.
- Click Adjust limit.
- Enter a dollar amount or choose Set to unlimited.
- Click Save.
The spend progress bar on the Extra Usage card shows how much of the monthly limit has been consumed. Once the limit is reached, additional purchases and auto-reloads are paused until the next UTC calendar month.
Canceling and Reactivating
Canceling a subscription schedules the cancellation for the end of the current paid period. Paid usage continues until that date. You can reactivate the same subscription before the period ends without starting a second checkout or creating an overlapping charge. Stripe subscriptions are finalized by Stripe; direct-billed subscriptions are normally finalized within a few minutes after the scheduled boundary. Management access remains available so you can review billing history and retained data.
Viewing Invoices
Workspace invoices
Invoice history for a workspace subscription is available under Settings → Billing → Invoices (/w/{wid}/settings/billing). Each invoice shows the billing period, amount, status, and a download link for the PDF.
Organization customer portal
If your organization is on a direct billing arrangement (not Stripe), a billing owner can view and download invoices from the customer portal. Contact your Gravity Rail account manager for portal access.
Related
- Analytics & Usage Reports — Detailed per-model, per-channel, and per-member usage breakdowns available under Settings → Billing → Detailed Reports.
- Organizations — Organization membership, roles, and general settings.
- Workspace Settings — Other workspace-level configuration.