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Use the Limit block to cap how many times customers can enter a specific chain inside a flow. Limits help you control spend on paid channels, smooth out load during peak periods, and hand out a finite number of rewards without overshooting.

When to use a Limit block

  • Cap spend on paid channels. Restrict the number of SMS or Flash Call sends so you stay inside budget.
  • Smooth infrastructure load. Spread sends over time instead of firing everything at once.
  • Distribute limited rewards. Hand out a fixed pool of loyalty points, promo codes, or discounts and stop once the pool is empty.

How the Limit block works

The block counts how many customers pass through it and compares that count against the cap you set. It has two output branches:
BranchWhat it does
Within limitRuns the main chain. Used while the counter is below the cap.
Beyond limitOptional. Runs an alternative chain (for example, a cheaper channel) once the cap is reached. If you leave it empty, customers who hit the cap exit the flow at this block.
While the flow is running, the block shows the current pass count and how much capacity is left.

Set up a Limit block

1

Add the block

Drag the Limit block into your flow and place it before the chain you want to cap.
2

Choose how the cap is counted

Pick one of two modes:
  • For all time — a single cap across the entire lifetime of the flow.
  • For a period — a cap that resets on a schedule. Choose hours, days, calendar days, or weeks.
3

Enter the number of passes

Set the maximum number of customers allowed through the Within limit branch.
4

Connect the branches

Wire the Within limit output to the chain you want to run for the first N customers. Optionally wire the Beyond limit output to a fallback chain.
5

Turn on threshold alerts (optional)

Enable a notification that fires a warning when remaining capacity drops below a level you choose — useful for catching a budget that’s about to run out before it does.

Editing a live Limit block

You can change a Limit block while the flow is running, but be aware of how each change affects the counter:
ChangeEffect on the counter
Change the number of passes onlyCounter is preserved. Existing pass statistics carry over.
Change the reset schedule (mode or period)Counter is reset. Pass statistics are cleared.
Changing the reset settings wipes the running totals. If you depend on historical pass counts, export them before you save the change.

How passes are counted

A customer’s run through the flow counts as a successful trigger only when a step group actually executes. If a customer enters the Limit block but the run ends there — for example, because they hit the cap and the Beyond limit branch is empty — that run is not recorded as a successful flow trigger. This matters when your flow has per-customer entry restrictions: a customer who stops at the Limit block can still be re-entered later, because the platform doesn’t count that pass as a completed trigger.

Design rules to keep counts accurate

Don’t place either of the following on the Within limit branch before the first step group:
  • Delay blocks
  • Additional Limit blocks
These can throw off the count. Put your first step group right after the Limit block, then add delays or further limits downstream.

Limits on the Limit block itself

You can add up to 5 Limit blocks per flow. If you need more, contact support.

Example: capping SMS spend

Say you want to send an SMS reminder but cap the cost at $500 a week, with an email fallback once the cap is hit.
1

Add the Limit block

Place it before the SMS send step.
2

Set the cap

Choose For a period, set the period to 1 week, and enter the number of SMS sends that fits your $500 budget.
3

Route the branches

Connect Within limit to the SMS send step. Connect Beyond limit to an email send step.
4

Add a threshold alert

Turn on the notification and set it to warn you when fewer than 10% of sends remain, so you can adjust before the week ends.
Pair the Limit block with a segment filter upstream to make sure only your highest-value customers reach the paid channel before the cap is hit.