Exotel Flow Builder

The Exotel Flow Builder is a visual, drag-and-drop tool for designing call flows without writing code. It provides a canvas where you arrange applets (building blocks), connect them with branches, and define how calls are handled from start to finish.

Accessing the Flow Builder

1. Log in to the Exotel Dashboard.
2. Navigate to App Bazaar (or Call Flows) in the left sidebar.
3. Click Create New Flow to start a new flow, or click on an existing flow to edit it.

The Flow Builder interface consists of:

Component	Description
Canvas	The main workspace where you arrange applets
Applet palette	The library of available applets (left panel)
Configuration panel	Settings for the selected applet (right panel)
Toolbar	Save, publish, undo, redo, zoom controls
Connection lines	Visual links between applets showing call flow paths

Available Applets

Communication Applets

Applet	Purpose	Outputs
Greeting	Play an audio message to the caller	Single output (proceeds to next)
IVR Menu	Present options and route by DTMF keypress	One output per key + timeout + invalid
Connect	Route the call to one or more agents	Answered, no answer, busy
Voicemail	Record a message from the caller	Single output (after recording)
Transfer	Transfer the call to another flow	Single output
Hangup	End the call	No output (terminal)

Notification Applets

Applet	Purpose	Outputs
SMS	Send an SMS to the caller or another number	Single output
Email	Send an email notification	Single output

Logic Applets

Applet	Purpose	Outputs
Passthru	Make an HTTP request to your server mid-call	Multiple outputs based on response
Business Hours	Check if current time is within schedule	Within hours, outside hours
Condition	Branch based on a variable or expression	True, false

See: Voice v1 Applets

Building a Call Flow

Step 1: Plan Your Flow

Before using the builder, sketch your call flow on paper or a whiteboard:

Start → Greeting → IVR (Sales/Support/Billing)
    Sales → Connect (Sales team) → No answer → Voicemail → Email
    Support → Connect (Support team) → No answer → Queue → Overflow → Voicemail
    Billing → Connect (Billing) → No answer → Voicemail

Step 2: Drag Applets onto the Canvas

1. From the Applet Palette on the left, drag each applet you need onto the canvas.
2. Arrange them in a logical sequence from left to right (or top to bottom).

Step 3: Connect Applets

1. Hover over the output port of an applet (small circle on the right side).
2. Click and drag a connection line to the input port of the next applet.
3. For applets with multiple outputs (IVR, Connect), connect each output to the appropriate destination.

Step 4: Configure Each Applet

Click on an applet to open its configuration panel:

Greeting Configuration:

• Audio source: Record, upload, or TTS
• Audio content: The message to play

IVR Menu Configuration:

• Prompt audio: The menu options
• Key mappings: Which key goes where
• Timeout: Seconds to wait for input
• Max retries: Times to repeat on invalid input

Connect Configuration:

• Agent numbers: Phone numbers to ring
• Ring strategy: Parallel, sequential, or round-robin
• Ring timeout: Seconds before moving to next output
• Recording: Enable or disable call recording
• Sticky agent: Enable or disable
• Queue: Enable with hold music and max wait time

Passthru Configuration:

• HTTP URL: Your server endpoint
• HTTP method: GET or POST
• Parameters: Data to send with the request
• Response handling: How to interpret the server response

Step 5: Test the Flow

1. Click Save to save your draft.
2. Click Test (if available) or temporarily assign the flow to an ExoPhone.
3. Call the ExoPhone from an external number.
4. Navigate through each path to verify correct behavior.

Step 6: Publish

1. Click Publish to make the flow active.
2. Assign the flow to your ExoPhone(s).

warning

Changes to a published flow take effect immediately for all calls on the assigned ExoPhones. Test thoroughly before publishing, especially during business hours.

Advanced Flow Patterns

Branching with Passthru

Use the Passthru applet to implement dynamic routing based on external data:

Start → Passthru (POST to your CRM)
    → CRM returns "VIP" → Connect (VIP team)
    → CRM returns "Standard" → IVR (standard menu)
    → CRM returns "Blocked" → Greeting ("Sorry, this service is unavailable") → Hangup

The Passthru applet sends the caller's number to your server, which looks up the caller in your CRM and returns a routing decision.

Nested Flows with Transfer

Break complex flows into smaller, reusable modules:

Main Flow:
    Greeting → IVR
        → 1: Transfer (Sales Flow)
        → 2: Transfer (Support Flow)
        → 3: Transfer (Billing Flow)

Sales Flow:
    Greeting (Sales welcome) → Connect (Sales team) → Voicemail

Support Flow:
    Greeting (Support welcome) → Queue → Connect (Support team) → Voicemail

Billing Flow:
    Greeting (Billing welcome) → Connect (Billing) → Voicemail

This keeps each flow simple and easy to maintain.

Error Handling

Always design for failure scenarios:

Connect (Agent group)
    → Answered: Call connected
    → No Answer: Voicemail → Email → Hangup
    → Busy: Queue → Voicemail → Email → Hangup
    → Failed: Greeting ("We are experiencing issues. Please try again later.") → Hangup

Looping (Repeat IVR)

To repeat an IVR menu after invalid input:

1. From the Invalid and Timeout outputs of the IVR Menu, connect back to the same IVR Menu applet.
2. Set a Max Retries limit to prevent infinite loops.
3. After max retries, connect to a fallback (e.g., Connect to operator, Voicemail).

Flow Versioning

Draft vs. Published

State	Description	Live Calls
Draft	Saved but not active	Not affected
Published	Active and handling calls	All incoming calls use this version

Reverting Changes

If a published flow has issues:

1. Open the flow in the builder.
2. Make corrections.
3. Save and republish.

tip

Before making significant changes to a production flow, clone it first. Work on the clone, test it with a test ExoPhone, and only publish to your main ExoPhone when verified.

Flow Templates

Exotel provides pre-built flow templates for common scenarios:

Template	Description
Basic IVR	Greeting + IVR Menu + Connect
Support Line	Greeting + IVR + Queue + Connect + Voicemail
After-Hours	Business Hours check + Live agents / Voicemail
Missed Call Callback	Auto-callback on missed calls
Survey	Outbound IVR with keypress collection

Access templates from the Create New Flow dialog in App Bazaar.

Performance Considerations

Factor	Impact	Recommendation
Number of applets	More applets = more processing time	Keep flows under 15 applets
Passthru response time	Slow server = delayed routing	Keep Passthru responses under 2 seconds
Audio file size	Large files = longer load time	Keep greetings under 30 seconds
Nested transfers	Multiple transfers add latency	Limit to 2 levels of transfer

Best Practices

• Start simple -- Begin with a basic flow and add complexity incrementally.
• Name applets clearly -- Give each applet a descriptive name (e.g., "Sales IVR Menu", "Support Connect") for easy identification.
• Always have a terminal -- Every flow path must end with a Hangup, Voicemail, or Transfer. No path should lead to a dead end.
• Test every path -- Call your ExoPhone and test every IVR option, timeout, busy, and no-answer scenario.
• Use templates -- Start with a template and customize rather than building from scratch.
• Document your flows -- Maintain a document or diagram of your call flows for team reference.
• Clone before editing -- Clone production flows before making changes.

Troubleshooting

Issue	Cause	Solution
Flow will not publish	Validation errors	Check for unconnected applets or missing configurations
Call hangs after greeting	Next applet not connected	Wire the Greeting output to the next applet
IVR not responding to keys	Key mappings not configured	Verify each key is mapped to an applet
Passthru timeout	Server response too slow	Optimize server response time
Flow not assigned to ExoPhone	Forgot to assign	Go to ExoPhones and select the flow

Related

• Setting Up a Call Flow
• IVR Setup
• Multi-Level IVR
• Smart Routing
• Voice v1 Applets