> ## Documentation Index
> Fetch the complete documentation index at: https://docs.assistable.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Use a flow on phone calls

> Assign a published flow to an assistant and test it through your existing phone-number setup.

A flow can provide the conversation path for a voice assistant. Configure the flow through the assistant; use the supported Assistable phone-number setup for call routing.

## Before you start

You need a tested, published flow, an assistant in the same subaccount, working voice settings with a standard voice (GPT Live voices cannot be combined with a flow), and a number configured for the intended inbound or outbound call path.

## Connect the flow

1. Publish the flow after checking its branches in **Test**.
2. Open the assistant's model selector and choose that published flow.
3. Review the assistant's voice in [Voice Studio](/v3/voice-studio).
4. Publish the assistant. This applies the assistant configuration to its voice agent.
5. Use your normal [inbound](/v3/guides/calling/incoming-calls) or [outbound](/v3/guides/calling/outbound-calls) setup to run a controlled call.

Publishing the assistant configures its voice integration for the assigned flow. Keep the number routed through the assistant’s supported phone-number setup.

## Verify on a real call

Ask something that takes a recognizable branch. Listen for the greeting, response timing, handling of interruptions, and the next question. Test a missing answer and an integration failure as well as the successful path.

If the flow transfers calls or writes to another system, check the transfer destination or external record. A correct spoken confirmation by itself does not prove the action completed.

## Reduce avoidable pauses

Keep node tasks focused, avoid loops through several model-powered steps, and use a short neutral filler for a slow tool. Keep dependent actions synchronous. Model choice affects behavior and response time; test it with the actual voice settings.

## Troubleshooting

* **Call reaches a different assistant:** check the number's routing and assistant assignment.
* **Assistant follows an old flow:** publish the latest flow, confirm its selection, then publish the assistant again.
* **Editor test passes but call audio fails:** inspect the voice and number setup; the editor runs text turns and does not test voice transport.
* **Flow pauses after a tool or branch:** check the tool result and connected default paths.

See [testing](/v3/guides/flows/test) and [model access](/v3/guides/flows/model-access).

## Which settings belong where

| Configuration | Where to set it |
| - | - |
| Conversation path, node prompts, variables, tool steps, flow model | Flow Builder. [All node types](/v3/guides/flows/first-flow#node-types), [variables](/v3/guides/flows/variables), and [models](/v3/guides/flows/model-access). |
| Flow assignment | Assistant’s model selector; published flows from the same subaccount. Selecting a regular model removes the flow assignment. |
| Voice, language/audio behavior, greeting, call timing | Assistant’s voice and [Call Settings](/v3/guides/voice/call-settings). A GPT Live voice is incompatible with a connected flow. |
| Inbound routing | Number’s assigned assistant and [incoming-call settings](/v3/guides/calling/incoming-calls). |
| Outbound caller ID and destination | The supported [outbound-call workflow](/v3/guides/calling/outbound-calls). |
| Transfer destination and behavior | A configured [transfer tool](/v3/guides/voice/transfer-calls) attached through a Tool node. The standalone Transfer palette node currently does not execute transfers. |

Publish a changed flow to update its conversation logic. Publish an assistant when applying its changed voice configuration. Test both directions you intend to use; an editor selector does not configure inbound or outbound telephony.


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