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	1.13 per segment, every plan
Phone call	2.0 per minute, every plan
Email	1 per message, every plan

Credits are tracked at the organization level — all workspaces in your organization draw from the same pool. Sites, inboxes, members, and storage are counts rather than hard plan caps. Phone lines also use one organization-wide pool, but the Product may include a number of lines; active lines above that inclusion carry a recurring lease charge on top of per-minute and per-segment credits. Additional lines are billed, not blocked by a hidden resource cap.

What can block you is not a count but a usage suspension — either automatic, when credits reach zero on an organization with hard credit enforcement on, or set deliberately after a payment failure, a credit dispute, or by a Gravity Rail administrator. While a suspension is in force it also blocks adding resources that cost money — buying a phone number, creating an inbox, or adding a member all check credit status first and return HTTP 402. (Gravity Rail administrators can still provision a member for you during a suspension; that path is administration, not customer usage.) See Credit enforcement below.

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	Annual	Included credits	AI discount	Telephony rate
Gravity Rail Basic	$20	$200	2,000	—	standard
Gravity Rail Pro	$200	$2,000	20,000	25% off	standard
Gravity Rail Max	$1,000	$10,000	100,000	50% off	standard

Annual billing is two months free. Higher tiers discount the work, not the credit — a credit is $0.01 on every plan, and a bigger plan makes the same call or chat consume fewer of them. In practice a 5-minute voice call costs about $0.84 at the entry tier, $0.66 on Pro, and $0.47 on Max.

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.

Choosing and changing plans

Because overage credits cost the same $0.01 as included ones, there is never a penalty for going over — which means the cheapest plan that covers you is always the right one. Upgrading pays off at exactly the point where the higher plan's fee is less than what you would spend on overage: 20,000 credits a month for Basic → Pro, and 100,000 for Pro → Max. (Plans are named Gravity Rail Basic, Gravity Rail Pro, and Gravity Rail Max; shortened here after first mention.) Gravity Rail will prompt you when your usage crosses one of those lines.

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 this workspace has used in the current billing period, your organization's active subscription, and this workspace's usage counts (members, sites, inboxes, phone numbers, storage). Those counts are not caps.
• Invoices tab — historical invoices for your organization's subscription, with download links.

The credit stat at the top of the Current Plan tab shows credits used this period against your organization's included credits, and the progress bar turns red past 90% of them. It deliberately shows no "remaining" figure: the cap belongs to the organization and every workspace draws on it, so "cap minus this workspace's usage" would be neither this workspace's headroom nor the organization's. For the organization-wide remaining balance, use the Organization billing tab below.

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 balance — remaining credits out of what was granted this period, the reset date, and the overage credit price ($0.01). This is the organization's ledger, not a sum of the workspace list below.

• Where credits were used — each workspace's share of credits already used in this organization this period. A row that says "88% of credits used" means that workspace accounted for 88% of consumption, not 88% of the plan allowance.

  Click any workspace row to open its breakdown, or use Expand all beside the section title to open every row at once. A row expands to show:

  • Credits by service — the same four services (AI, SMS, voice, email) as the organization-wide bar, for this workspace alone.
  • AI credits by model — the AI figure broken down by the model that consumed it. These rows add up to the AI service above them; they are not a fifth service. A workspace that used no AI says so, which is a different statement from a workspace whose usage could not be read.
  • Metered quantities — the voice minutes, SMS segments, emails and member seats behind the credits, so a credit figure can be checked against the units it was billed for. Voice appears twice on purpose: connected minutes are the raw call time, and billed minutes round each call up to the minute, which is what the charge is calculated from.

  Everything in the breakdown arrives with the page, so expanding is instant and costs no extra loading.

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

1. Go to Organization settings → Billing → Extra Usage.
2. Toggle Enable extra usage on.
3. 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.
4. 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:

1. Go to Organization settings → Billing → Extra Usage, or click Top up credits on the out-of-credits banner.
2. Click Buy extra usage (or choose an amount in the banner dialog).
3. Confirm the purchase.
4. After the payment succeeds, the same dialog offers Set up auto-reload. Turn it on here, or choose Not now.

Credits are applied immediately after the payment is processed. Auto-reload is optional; skipping it does not undo the purchase.

If you cannot open Billing, ask the billing owner for your organization — auto-reload and payment methods live on the organization billing page, not workspace settings.

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

1. Go to Organization settings → Billing → Extra Usage.
2. Click Adjust limit.
3. Enter a dollar amount or choose Set to unlimited.
4. 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.

Phone lines and messaging registration

Your organization Product specifies how many phone lines are included across all workspaces. Active lines beyond that inclusion appear as grouped local or toll-free overage. Stripe subscriptions and direct invoices use the same count; there is no separate operator override and adding a phone does not create a new subscription. Changing the plan changes future billing, while an already-issued invoice remains unchanged.

A2P 10DLC registration/vetting is a one-time Brand/Campaign event charge. Its recurring Campaign service begins only after approval. Toll-free SMS verification is a separate carrier process. These registration charges are not additional phone lines.

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.