Flow Builder

What is the Flow Builder?

The Flow Builder is where you design exactly how your AI handles phone calls. Using a visual drag-and-drop canvas, you create a series of steps — like asking a question, speaking a message, or checking a condition — that your AI follows during a call.

Think of it like drawing a flowchart: each box is a step in the conversation, and lines connect them to show the order. When a caller phones in, your AI walks through this flowchart from top to bottom.

What You Can Do Here

Getting Started

Node Types Explained

Each step in your flow is a "node." Here's what each type does:

Ask Node — In Detail

The Ask node is one of the most powerful and commonly used steps. Here's how to get the most out of it:

Writing the Prompt

This is what the AI says to the caller. Keep it short and clear — remember, people are listening, not reading. For example: "What's your account number?" works better than "Could you please provide me with the account number associated with your profile?"

Setting a Variable Name

The caller's answer is saved to a variable you name. Use descriptive names like account_number or date_of_birth, not vague names like value1. You can use these variables later in other nodes by writing {{account_number}}.

Validation

You can add rules to make sure the caller's answer is in the right format. For example, require exactly 10 digits for a phone number. If the answer doesn't match, the AI will ask again.

Confirmation

For important information like account numbers or dates, turn on confirmation. The AI will repeat back what it heard and ask "Is that correct?" before moving on.

Retry Logic

Set how many times the AI should re-ask if it doesn't understand. You can write custom retry messages that get progressively more helpful, and decide what happens after the maximum retries (usually escalate to a human).

Using Variables

Variables are how information flows through your procedure. When an Ask node collects a piece of data, or an Action node fetches something from an API, the result is stored in a variable that you can use in later steps.

To insert a variable into any text field, use double curly braces:

Built-in Variables

These are always available, even without any Ask or Action nodes:

• {{caller_phone}} — The caller's phone number
• {{callSid}} — A unique ID for this call
• {{last_asr}} — The last thing the caller said (speech recognition result)

Flow Builder vs. Agentic Procedures

BLEUM offers two ways to build call procedures. Here's how to decide which to use:

System Flows — Welcome and Escalation

Every BLEUM account has two built-in system flows that run automatically and cannot be deleted: the Welcome flow and the Escalation flow. You can edit and customise them, but they are always present.

Welcome flow

The Welcome flow is the entry point for every incoming call. When a caller rings your number, the Welcome flow runs first — before any of your published procedures. It typically plays an opening message, optionally gathers some initial context, and then the AI routes the caller to the most relevant published procedure based on what they say.

By default the Welcome flow contains a single Say node with a generic greeting. You can edit it to match your brand — add your company name, set the tone, or use an Ask node to gather the caller's name or account number upfront before routing begins.

Escalation flow

The Escalation flow handles transfers to a human agent. It only runs when a published procedure explicitly triggers escalation — for example, when a caller asks to speak to a person, or when an after-hours condition routes them out. It is not the default ending for calls; most calls resolve fully through your published procedures without ever reaching escalation.

The Escalation flow contains a Say node (your hold message) and an Agent Escalation node where you configure phone forwarding or Zendesk Talk routing.

How system flows appear in the interface

System flows are shown in the System Flows section at the top of the Flow Builder list — separate from your published and draft procedures. They have a lock icon indicating they cannot be deleted. You can click either system flow to open and edit it on the canvas just like any other procedure.

The Call Journey rail at the top of the Flow Builder page shows you a live visual of the full call path: Incoming call → Welcome → Your procedures (the AI routes dynamically between them) → Call resolved or Escalation if needed.

Line Group Assignment

If your organization has Line Groups set up (on the Phone Numbers page), each procedure must be assigned to one or more groups before callers on those lines can reach it. The assignment is controlled directly from the canvas header when you open a procedure.

The "Available on" row

When you open a procedure in Flow Builder, you'll see an Available on: row just below the back button. It shows each of your line groups as a checkbox. Check the groups this procedure should be available to. If all groups are checked, the hint reads "Available to all line groups" in green.

How procedures are grouped in the list view

On the Flow Builder list page, published procedures are organized into buckets based on their exact group assignment — for example, procedures assigned to only "Sales" appear under a Sales heading, and procedures assigned to both "Sales" and "Support" appear under their own combined heading. This makes it easy to see at a glance which procedures serve which lines.

Publishing and Drafts

Every procedure starts as a draft. Drafts are only visible to you — they won't affect live calls. When you're ready, click Publish to make the procedure available for incoming calls.

After publishing, you can still make changes. Just edit, save as a draft, and publish again when you're ready. Your previous published version stays live until you publish the new one.

Tips & Best Practices

• Start simple — Build a basic flow first, test it, then add complexity. It's easier to troubleshoot a small flow than a large one.
• Save drafts often — Your work isn't automatically saved. Click "Save Draft" frequently, especially after making big changes.
• Keep prompts conversational — Write the way you'd speak. Avoid formal or robotic language.
• Use descriptive variable names — date_of_birth is much clearer than dob when you revisit the flow later.
• Enable confirmation on critical data — Account numbers, dates, and phone numbers should always be confirmed with the caller.
• Plan for errors — Always set retry messages and decide what happens when the caller can't provide valid input.
• Test with real calls — The best way to find issues is to call your number and go through the flow yourself.

Common Questions