How credits, allocations, and billing plans work

Billing & Credits

Vindex Ai Gateway uses a credit-based system to meter AI usage. This page explains how credits work, how they are allocated, and what happens when they run out.

How Credits Work

1 credit = 1,000 tokens of AI model usage (input + output combined). Different AI models consume credits at different rates — larger models cost more per token.

Your tenant account has three credit pools:

Pool	Purpose
Main balance ( text `credits_balance` )	Your primary credit pool. Shared between channels and your assistant.
Assistant reserve ( text `assistant_reserve` )	Credits reserved exclusively for the tenant portal assistant. Channels cannot touch these.
Expiry credits ( text `expiry_credits_balance` )	Bonus credits from bundle purchases that expire at a set date. Consumed first.

Credit Consumption Order

When an AI request is made, credits are consumed in this order:

Expiry credits (if active and not expired)
Main balance (or assistant reserve, depending on the source)

Credit Allocation to Channels {#credit-allocation-to-channels}

Each channel you create has a spending cap called

text

credits_allocated

. This is a per-channel limit — not a reserved sub-pool.

How Channel Allocation Works {#how-channel-allocation-works}


text
Tenant main balance: 1,000 credits
├── Assistant reserve: 500 (assistant only)
└── Allocatable pool: 500 (channels can use)
    ├── Channel A: cap = 200, consumed = 150  ✓ Working
    ├── Channel B: cap = 300, consumed = 300  ✗ Blocked (cap reached)
    └── Unallocated: 0

text
credits_allocated
— the maximum credits this channel is allowed to consume
text
credits_consumed
— total credits this channel has used so far
When
text
```
consumed >= allocated
```
, the channel's AI returns a 403 error to visitors
Credits are deducted from the tenant's shared balance, not from the channel's allocation specifically
The allocation is a ceiling, not a reservation — Channel A's unused credits do not transfer to Channel B

Allocating Credits

Go to Portal → Credits (or click "Allocate Credits" in the dashboard)
Adjust the Assistant Reserve if needed — this changes how many credits are reserved exclusively for the portal assistant
Enter the
text
```
credits_allocated
```
value for each channel
Click Save Allocations
The total across all channels cannot exceed your allocatable pool

Allocatable pool =
text
credits_balance
−
text
assistant_reserve
− already-allocated credits

Tip: Increasing the assistant reserve reduces the pool available for channels, and vice versa. Adjust based on your usage patterns.

Expiry Credits

If you purchase an expiry bundle (one-time credit purchase), those credits:

Have an expiration date shown in the allocation modal
Are consumed first before your main balance
Any unspent allocated credits from the expiry pool are lost when they expire
The allocation modal shows a warning banner when expiring credits are detected

Tenant Portal Assistant

The assistant in your portal uses a dedicated credit pool:

Expiry credits (if active) +
text
assistant_reserve
It cannot use credits from the channel allocatable pool
When the assistant's pool reaches 0 and you have no billing plan, the assistant becomes unavailable

This ensures your assistant stays functional even when all channel allocations are consumed.

What Happens When Credits Run Out

Channel Exhausts Its Allocation

Channel's
text
```
credits_consumed
```
reaches
text
```
credits_allocated
```
Channel's AI assistant returns 403 with message: "This channel's AI assistant is currently unavailable due to reaching its allocated credit limit."
To restore: Increase the channel's allocation from the Credits page, or purchase more credits

Tenant Assistant Exhausts Its Reserve

text
```
assistant_reserve
```
reaches 0
Assistant returns error: "Your AI assistant is currently unavailable. Please top up your credits."
To restore: Purchase more credits or increase the assistant reserve (which reduces the channel pool)

Entire Tenant Balance Reaches Zero

Both channels and assistant are blocked
Portal access remains active — you can still manage settings, view usage, and purchase credits
To restore: Purchase a plan or top up credits

Billing Plans

Billing plans provide ongoing credit access and additional features:

Feature	No Plan	With Plan
Credits	One-time purchase only	Monthly credits included
Overage	Blocked at 0	Continues working, billed at cycle end
Overages charged	N/A	Charged to stored card at billing cycle end

Overages

If you have an active subscription plan and your credits reach 0:

Your AI assistants continue working
Usage beyond your balance is tracked as
text
overage_credits
At the end of the billing cycle, overages are charged to your stored payment method
This prevents service interruption while keeping costs transparent

Lifecycle States

Your tenant account moves through these states:

State	Condition	Effect
Active	Has credits or a plan	Full access
Empty	No plan + no credits	AI blocked, portal accessible
In Grace	Payment failed, within grace window	AI blocked, portal accessible
Expired	Grace period expired	AI blocked, portal accessible
Suspended	Admin action	All access blocked

Low Balance Alerts

When your credit balance drops below 10% of your plan's included credits (or 10% of 1,000 if no plan), you receive a notification. Alerts are rate-limited to once per 24 hours.