Overview
Luminous gives you two independent ways to control how much inventory is published to a sales channel. They serve different purposes and are applied in sequence.
Buffer quantity (subtractive reserve)
A buffer subtracts a fixed number (or a percentage) from your available stock before the quantity is sent to the channel.
Example: 500 units on hand, buffer of 50 → channel is told 450.
Use a buffer to:
- Keep safety stock off a channel so urgent orders can always be fulfilled.
- Shave a percentage off availability during slow periods.
Max Push Quantity (absolute ceiling)
A Max Push Quantity caps the published number from above. The channel will never be told you have more than this, regardless of actual stock.
Example: 500 units on hand, no buffer, cap of 200 → channel is told 200.
Use a cap to:
- Prevent a marketplace or EDI trading partner from seeing a very large inventory spike that could lead to overselling or vendor penalties.
- Suppress stock entirely on a channel (set cap to 0) without removing the product mapping.
- Protect a drop-ship channel from receiving more units than you can actually fulfil through that route.
Order of operations when both are set
- Start with your available quantity.
- Subtract the buffer (fixed units or percentage). Result is clamped at zero if negatives are not enabled.
- Apply the cap. If the post-buffer quantity exceeds the cap, the cap value is published. If it is already below the cap, the lower number is published unchanged.
Combined example:
- 500 on hand
- Buffer: 100 units
- Cap: 300 units
- After buffer: 400 → clamped to 300 by the cap.
Another example where the cap does not fire:
- 40 on hand
- Buffer: 0
- Cap: 200
- Published: 40 (the cap is a ceiling only; it never inflates a lower quantity).
At a glance
| Buffer | Max Push Quantity | |
|---|---|---|
| What it does | Subtracts a reserve | Clamps the published number from above |
| Applied | Before the cap | After the buffer |
| Can raise a quantity? | No | No |
| Set to 0 means | No buffer | Publish nothing to this channel |
| Leave blank means | No reserve | No cap (full buffered quantity is published) |
Both settings follow the same precedence chain: a per-product value overrides a channel-wide default, which in turn overrides a base product default.