How to Test Twilio IVR Flows With TestMu AI

A Twilio IVR is a scripted flow built in Studio or TwiML, not a conversational AI agent. It matches on keypad digits and fixed speech results rather than intent, so coverage means traversing every menu branch rather than probing free-form conversation. The TestMu AI Agent Testing Platform dials the number, walks every path a caller can take, and scores each run, so you can test the whole IVR without changing the flow.

To connect one, you need a Twilio account with a published Studio flow or TwiML application, the provisioned number running it, the flow export or menu map, and a TestMu AI workspace with agent-testing permissions.

How do you run an IVR test in the dashboard?

Follow these six steps in the dashboard.

Step 1: Create the IVR agent. In the Agent Testing page, click Create New Agent, then fill in the form:

Agent Name (required).
Description (optional).
Agent Type (required): select IVR Agent.

Click Create New Agent to confirm.

Create New Agent panel with IVR Agent selected as the agent type

Step 2: Add the IVR specification. Open the Prompt tab.

In Agent-Under-Evaluation Prompt, define the ideal behavior and role of your IVR to guide conversations. The example specification covers the IVR's role, DTMF conventions, and global menu commands.
Optionally, under Upload Files, add PDF, MS Word, MS Excel, TXT, MD, MP3, WAV, M4A, PNG, JPG, or WEBP files. Multiple files are allowed, up to 5 MB each.
Optionally, under Import from Jira, enter a Jira issue key or URL and click Import to load a ticket into the editor. This needs Jira to be connected first: click Connect Jira if it isn't.
Click Save Prompt.

Prompt tab with a telephone banking IVR specification, file upload and Jira import

Step 3: Review the IVR System Map. Open the IVR System Map tab to see every menu, branch, and dead-end the platform mapped for your IVR.

Summary cards: Menus, Decision points, Deepest path (levels), Reachable paths, and Dead-ends found.
Node types: Start, Menu, Decision, Input, Self-service, Agent transfer, End call, and Error / reprompt.
Edge types: DTMF, Speech, and System.
Use the zoom controls and the minimap to move around the diagram.

IVR System Map showing counts of menus, decision points, deepest path and reachable paths with a node diagram

Step 4: Create a suite. On the Suites tab, click Create New Suite.

Enter a Suite Name.
Optionally, select an Agent Profile. It applies only to scenarios that don't have a profile set on the Scenarios page, and a scenario-level profile overrides it.
Choose the Region. Inbound calls originate from that region's phone number, and the default is US.
Use Search scenario and the checkboxes to select the scenarios to run.
Check the footer, which shows the number of calls and the availability, for example 1 call · 1/1 available, then click Create New Suite.

Step 5: Run the suite. Click Run next to your suite. Every call in the suite is a real call to your IVR's number, so the Confirm Run dialog lists each one before anything is dialed. Check that the number of calls, the Region, and each call's voice and background noise are what you intended, then click the trigger button, such as Trigger 1 call, to start.

Confirm Run dialog listing the IVR scenario, voice, background noise and iteration with the Trigger 1 call button

Step 6: Review the call results. Open a call from the list to see whether it passed and why.

Check how each call ended first. A call marked dispatch-failed never connected, so it has no score to review.
For a connected call that failed, play it on the Recording tab alongside the transcript to find the menu step where it went wrong. The usual causes are a digit that didn't register, a speech fallback that never triggered, a drop on timeout, or an unreachable transfer target. See why Twilio IVR tests fail.
On the Validation Results tab, check which of the scenario's success criteria the call met or missed.
If a call failed but the flow looks right, check the MOS badge. A call's pass or fail can be based on the metrics, on the mean opinion score of the call audio, or on both.

IVR call result showing pass status, score, MOS, call recording waveform, call summary and transcript

How do you test every branch of a Twilio IVR?

Because an IVR is a decision tree, coverage is measured in branches, not intents. Upload the flow export or menu map and TestMu AI generates a scenario for each path a caller can take, then dials the provisioned number and walks them: DTMF entry, speech input fallback, timeout and retry behaviour, and transfer to a queue or a representative. See phone agent testing for the full setup.

What makes testing a scripted IVR different?

An IVR matches on input rather than intent, so its failure modes are about input handling, not comprehension:

Two input paths. Speech input and keypad input follow different branches, and both need coverage.
Timeout and retry is the failure surface. Input collection fails on timing, not comprehension, so build scenarios that trigger timeout and retry.
Per-step barge-in. Barge-in is configured per input step rather than globally, so test it on each step that enables it.
Scripted-flow metrics. Hallucination, grounding, and safety metrics do not apply to a scripted flow. Leave them off.
AI voice is a different setup. Teams running Twilio's AI voice product connect over a WebSocket to their own application, a separate path.