A call flow tells Nimbata what to do with a call from the moment someone dials one of your tracking numbers. This page explains how call flows work, the actions they are built from, and how to build one from scratch or from a template.

How call flows work

A call flow is a set of instructions that tells Nimbata what to do from the moment someone dials one of your tracking numbers. Every call that comes in follows the flow you’ve built, in the exact order you’ve set up.

You design call flows visually in the Call Flow Builder, a canvas where you add and connect actions. The result is a path a call travels through. It might be:

  1. Greeted
  2. Recorded
  3. Filtered by time or keypad input
  4. Then connected to a destination number.

What a call flow can do

Call flows are built from three types of actions: add-ons, filters, and routing options.

Add-ons layer features on top of a call without changing where it goes:

  • Record: records the conversation for training, compliance, or quality monitoring.
  • Greeting: plays an audio message to the caller before the call connects (for example, “Thank you for calling, please hold.”).
  • Whisper: plays a short private audio cue to the agent the moment they pick up (for example, “Call from Google Ads.”).
  • Mask caller ID: changes the number the agent sees when a call arrives: no number (anonymous, the default), the tracking number the caller dialed, or the destination number. Showing the tracking number tells agents which campaign the call came from.
  • Call survey: prompts the agent to score the call. It starts when the caller hangs up, or earlier if the agent presses *.

Filters inspect an attribute of the call and branch the flow accordingly:

  • Keypad entry: prompts the caller to press a key or type a code, and routes down the matching branch (IVR). It needs a Greeting in the flow to ask the question.
  • Day of week: routes differently depending on which day the call arrives.
  • Time of day: routes based on the time of the call (for example, business hours vs. after-hours).
  • Caller ID prefix: reads the first digits of the caller’s number and routes based on country and area code.

Routing options decide where the call is connected:

  • Dial: connects to a single destination number.
  • Multiple: rings several destinations simultaneously; the first to answer takes the call.
  • Sequential: rings destinations one at a time in order.
  • Weighted: distributes calls across destinations by percentage.
  • Round robin: sends each call to the next destination in turn.
  • Voicemail: sends the call to a recorded mailbox.
  • Hang up: ends the call immediately.

Every path in a call flow must end in an action that resolves the call: Dial, Multiple, Sequential, Weighted, Round robin, Voicemail or Hang up. A path without one is marked invalid, and the call flow can’t go live until you add one. If you edit a call flow that is already live and leave it invalid, the last valid version stays live, and the builder says your latest changes are not live until you fix or revert them.

How call flows connect to tracking numbers

A call flow does nothing on its own. It must be assigned to a tracking number (or a swap group) before it takes effect. You can assign the same flow to multiple numbers, or give each number its own flow.

Call flows vs. workflows

Call flows control what happens during a call:

  • Routing
  • Recording
  • Greeting
  • IVR

Workflows control what happens after a call ends:

  • Sending conversions
  • Triggering alerts
  • Updating tags
  • Pushing data to integrations

The two work together but serve different purposes.

Detailed guide: Build a call flow
Detailed guide: Add-ons, filters and routing options
Detailed guide: How workflows work

Build a call flow

Tip

Before you start: make sure you add at least one destination number before building a call flow: Add a destination

The Call Flow Builder is a canvas where you design how incoming calls are handled and routed from the moment a tracking number is dialed. Every path in a call flow must end in an action that resolves the call, such as Dial, which connects the call to a destination (see How call flows work). Everything else (greetings, recording, IVR, whispers, filters) is layered on top.

  1. Open the Call Flow Builder

    Go to Call handlingCall Flows, click Create, then From Scratch.

    A new call flow starts with New Call and a Dial step that rings your destination. If the project has several destinations and your plan includes Multiple routing, the step becomes Multiple and rings them all (the verified ones, when some are not); pick Dial in the step to ring just one. Otherwise the Dial step is left empty for you to pick the number.

  2. Add actions to your call flow

    Click the + button on the canvas to open the action menu. Add any combination of the following:

    • Dial: routes the call to a destination number
    • Record: starts call recording
    • Greeting: plays a message the caller hears before connecting
    • Whisper: plays a private audio cue the agent hears when they pick up
    • Mask Caller ID: controls what number appears on the agent’s screen
    • Keypad Entry: creates an IVR menu for caller input
    • Voicemail: captures a message when no one answers
    • Call Survey: prompts the agent to score the call
    • Sequential / Weighted / Round robin: distribute calls across multiple destinations
    • Day of Week / Time of Day / Caller ID Prefix: conditional routing filters

    Tip

    Conditional actions (Keypad Entry, Day of Week, Time of Day, Caller ID Prefix) route calls down different branches: click the + above one and choose Split to add a branch.

    Main lineCall flow is valid. Assign to Tracking Number
    New Call
    Greeting
    Text to speechPress 1 for emergencies, 2 for everything else
    Keypad Entry
    1
    Dial
    Emergency line(415) 555-0119
    Keypad Entry
    2
    Day of Week
    Mon, Tue, Wed, Thu, Fri
    Dial
    Main office(415) 555-0110
    Day of Week
    Sat, Sun
    Voicemail
    System
    1
    A call flow on the canvas. Click a + (1) to add an action there; each path ends in an action that resolves the call.

  3. Assign the call flow to a tracking number

    Go to TrackingNumbers and assign the call flow:

    • Either at the swap group level (shared across multiple tracking numbers) OR
    • At the tracking number level (applies to one number only).

    Tracking Numbers

    Phone numbers that capture incoming calls and attribute them to a source.

    (415) 555-0142US · Local
    No call flow
    Google Ads
    Select a call flow1
    At the tracking number level: click Select a call flow (1) on the number and pick your call flow.

🎉 That’s it. Whenever someone calls the tracking number, they’ll follow the flow you just built.

Detailed guide: Mask the caller ID
Detailed guide: Turn on recording
Detailed guide: Add a greeting
Detailed guide: Add a whisper
Detailed guide: Score calls with surveys
Detailed guide: Route by caller location
Detailed guide: Build a keypad menu
Detailed guide: Route by day of week
Detailed guide: Route by time of day
Detailed guide: Ring several numbers at once
Detailed guide: Ring numbers in order
Detailed guide: Split calls by percentage
Detailed guide: Set up and listen to voicemail

Add-ons, filters and routing options

Note

This section covers Call Flow Actions. For Workflow Rules & Tasks, see: Rules and tasks.

Call flow actions are the building blocks of every call flow. They fall into three groups: Add-ons, Filters, and Routing Options. Combine them in the Call Flow Builder to shape how each inbound call is handled.

You add them in sequence with the + button. The menu that appears changes depending on where in the flow you are: before or after the Dial module. Below are the three categories of modules, how they interact, and how the builder guides you toward a valid flow.

Add-ons

Add-ons enhance the call experience for the caller or agent. They layer features on top of a call without changing its destination: they add behavior around the routing.

  1. Mask Caller ID: shows the agent no number (anonymous, the default), the tracking number or the destination number instead of the caller’s real number. Showing the tracking number tells agents which campaign or line the call came from.
  2. Record: automatically records inbound calls for training, compliance, and quality monitoring. Recording doesn’t announce itself: add a Greeting before it if your callers must be told.
  3. Greeting: plays a customizable audio message to the caller before the call connects. For example, “Thank you for calling, please hold while we connect you.”
  4. Whisper: plays a short audio cue only to the agent the moment they pick up, providing context such as the campaign source. For example, “Call from Facebook Ads.”
  5. Call Survey: presents an interactive voice survey to the agent when the caller hangs up, or earlier if the agent presses *. Agents can use it to rate quality or confirm lead outcomes.

Filters

Filters inspect an attribute of the incoming call and conditionally split the call flow into separate paths based on what they find. Filters are only available before the Dial module.

  1. Caller ID Prefix: reads the first digits of the caller’s number and routes the call accordingly. A prefix starts with the country code: for example, 1312 sends Chicago calls down their own branch.
  2. Keypad Entry: prompts the caller to press a key or type a code, and routes the call down the matching branch. For example, “Press 1 for Sales, 2 for Support.” It needs a Greeting in the flow.
  3. Day of Week: routes calls differently depending on which day they arrive. For example, weekdays to the sales team and weekends to voicemail.
  4. Time of Day: routes calls based on the time they arrive. For example, business hours to live agents and after-hours to voicemail.

Routing options

Routing options decide where the call ends up: they define how and where a call is delivered. Every path in a call flow must end in one of them (or in Voicemail or Hang up). Dial is the default.

  1. Dial: connects the call to a single destination number.
  2. Multiple: rings several destination numbers simultaneously. The first to answer takes the call.
  3. Sequential: rings destination numbers one at a time in a defined order until someone answers.
  4. Weighted: distributes calls across destinations according to percentages you set. For example, 70% to Team A and 30% to Team B.
  5. Round robin: sends each call to the next destination in turn, so two destinations alternate: A, B, A, B.
  6. Hang up: ends the call immediately without connecting to anyone. No further modules run after Hang up.
  7. Voicemail: sends the call to a recorded mailbox (a voicemail inbox) so the caller can leave a message.

On the canvas, a routing step shows these options at its top: Ring (Dial, Multiple, Sequential, Weighted, Round robin) and Instead (Hang up, Voicemail). Click one to switch the step to it. Multiple, Sequential, Weighted and Round robin need at least two destinations.

Dial✕
Ring
DialMultipleSequentialWeightedRound robin
Instead
Hang upVoicemail

Rings a single destination.

Destination
Main office(415) 555-0110
Receive SMSAlso receive an SMS to your destination when supported by the tracking number.
The routing options at the top of a routing step: Dial is active, and the line under them says what it does.

What appears before and after Dial

The + button above Dial gives you access to:

  • Add-ons: Mask Caller ID, Record, Greeting
  • Filters: Caller ID Prefix, Keypad Entry, Day of Week, Time of Day

The + button below Dial gives you access to:

  • Add-ons: Whisper, Call Survey
  • Routing Options: Voicemail
Select a call-flow action✕

Enhance the call experience with call add-ons and features

  • Add-ons
  • Mask Caller ID
  • Record
  • Greeting
  • Filters
  • Caller ID Prefix
  • Keypad Entry
  • Day of Week
  • Time of Day
The action panel of the + above Dial: add-ons and filters only.

This separation reflects the logic of a call: you prepare and filter before routing, and you follow up after. To see the full menu of available modules, remove the default Dial module. This reveals all add-ons, filters, and routing options in one view.

How filters work

Adding a filter creates a module that defines the condition, with a corresponding routing module attached for calls that match it. Every call must have a route, so a filter always covers everyone:

  • Caller ID Prefix adds an All other prefixes branch for callers who match no prefix.
  • Keypad Entry needs a No match / No input branch when callers type codes.
  • Day of Week and Time of Day branches must cover all seven days and the whole 24 hours between them.

To carve off additional paths, click the + above the filter module and choose Split. Each split handles the calls assigned to it. Nimbata won’t save a call flow that leaves some calls with no route, or with more than one.

Each filter type partitions calls differently:

  • Day of Week: splits calls by day. All 7 days are pre-selected on the first path. Add splits to assign specific days to separate paths.
  • Time of Day: splits calls by time window, using the same pattern as Day of Week.
  • Caller ID Prefix: creates a path per prefix. Calls matching a given prefix are routed down that path; all others fall through.
  • Keypad Entry: creates a path per key or code the caller enters. A path can hold several keys or codes (up to 9 digits each), and the No match / No input path takes the rest.

Each split path can have its own add-ons and routing options added to it independently.

Tip

Detailed guide: Build a keypad menu

Execution order

Call flows execute top to bottom, in the order modules appear in the builder. The + button only surfaces options that are valid at each position, so the builder steers you toward a structurally sound flow.

A typical flow might look like this:

  • A Greeting plays to the caller
  • A Day of Week filter checks which day it is:
    1. Monday to Friday > Dial to the office
    2. Saturday to Sunday > Voicemail
  • A Whisper plays to the agent when they answer
  • A Call Survey runs after the call ends

Warning

Filters must be placed before Dial. Add-ons that apply to the agent (Whisper) or follow the call (Call Survey) must be placed after Dial. The builder enforces this by showing only valid options at each + button position.

Detailed guide: Build a call flow
Detailed guide: Assign a call flow
Detailed guide: Mask the caller ID
Detailed guide: Turn on recording
Detailed guide: Add a greeting
Detailed guide: Add a whisper
Detailed guide: Route by caller location
Detailed guide: Build a keypad menu
Detailed guide: Route by day of week
Detailed guide: Route by time of day
Detailed guide: Ring several numbers at once
Detailed guide: Ring numbers in order
Detailed guide: Split calls by percentage
Detailed guide: Set up and listen to voicemail

Start from a template

Note

To build this call flow manually using the full Call Flow Builder instead, see: Build a call flow

A Simple Call Flow routes every incoming call straight to one destination number. It’s the fastest way to get a tracking number live and is a good starting point before adding greetings, recording, or routing rules.

  1. Open the template picker

    Go to Call handlingCall Flows, click Create, then select From Template.

    Create a New Call Flow
    Choose how you’d like to create your call flow
    From ScratchCreate a completely custom call-flow tailored to your specific needs. Full control over every step and action.
    1From TemplateStart with a pre-built template and customize it to your needs. Quick setup with proven call flows.
    Choose From Template (1). From Scratch opens a new call flow with a Dial step instead.

  2. Choose the Simple Call Flow template

    On Simple Call Flow, click Use template.

    Call Flow TemplatesStart with a call flow template, customize as you go.
    Simple Call Flow
    Route calls directly to a single number.BasicRouting
    Simple with recording
    Record the call before routing it to a single number.BasicRecording
    Simple with whisper
    Play a whisper message to the agent before connecting the call.BasicAgent Tools
    On the Call Flow Templates page, click Use template (1) on Simple Call Flow.

  3. Check the destination number

    • The template is created and named automatically, and its Dial step is filled with your destination number.
    • If the project has several destinations and your plan includes Multiple routing, the step rings them all (Multiple). To ring one number only, click Dial in the step’s Ring options, then choose the number under Destination.
    Multiple✕
    Ring
    Dial1MultipleSequentialWeightedRound robin
    Instead
    Hang upVoicemail

    Rings every destination at once. The first to answer gets the call.

    2 destinations selected
    Sticky destinationsRepeat callers go to the destination that answered them within the look back period.
    With two destinations the step rings both. Click Dial (1) to ring a single number, then choose it under Destination.

🎉 Your Simple Call Flow is ready.

Assign it to a tracking number under TrackingNumbers to go live.

Detailed guide: Assign a call flow