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Documentation Index

Fetch the complete documentation index at: https://docs.usetuner.ai/llms.txt

Use this file to discover all available pages before exploring further.

For an overview of how simulation works, see Introduction to Call Simulation.

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Prerequisites

  • A Vapi account with an active assistant
  • An agent created in Tuner with prompt and evaluation rules configured (see Connecting to Vapi)
  • Tuner credits available for simulation calls

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Step 1: Create a SIP Trunk in Vapi

  1. Log in to the Vapi dashboard.
  2. Go to Phone Numbers in the left sidebar.
  3. Click Create Phone Number → select Free Vapi SIP.
  4. Fill in the trunk details:
    • SIP Identifier: A name for your trunk (e.g. targettuneragent)
    • Label: A reference label (e.g. testing)
    • Username: A SIP authentication username
    • Password: A SIP authentication password
  5. Click Import SIP URI.
Creating a Free Vapi SIP trunk with credentials You’ll need these credentials in the next step:
FieldExample
SIP URIsip:targettuneragent@sip.vapi.ai
Username(the username you chose)
Password(the password you chose)
Save your SIP credentials immediately. Vapi only displays the password once during creation. If you lose it, you’ll need to delete the trunk and create a new one.

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Step 2: Configure SIP in Tuner

  1. In Tuner, go to Agent Settings → SIP Settings.
  2. Enter your Vapi SIP trunk details:
    • SIP URI: sip:<identifier>@sip.vapi.ai
    • Username: The username from Step 1
    • Password: The password from Step 1
  3. Click Test Connection, then Save.
SIP configuration in Tuner A Verified badge appears next to the SIP URI once the connection succeeds.
  1. In the Vapi dashboard, go to Phone Numbers.
  2. Click on the SIP trunk you created.
  3. Under Inbound Settings, set the Assistant field to the agent you want to test.
  4. Click Save.
Linking your assistant to the SIP trunk in Vapi
If the assistant is not linked to the trunk, simulation calls will fail to connect. This is the most common setup issue.

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Step 4: Run Your First Simulation

  1. In Tuner, open Simulations in the sidebar.
  2. Click Run Simulation.
  3. Confirm the SIP target is correct.
  4. Set the number of calls (5–20).
  5. Adjust the simulation mix (routine vs. pressure).
  6. Click Run.
Configure and launch your simulation Results appear in the Simulations table once calls complete. Click any row for the transcript, latency breakdown, and evaluation results.

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Troubleshooting

SymptomResolution
Calls fail to connectDouble-check SIP credentials in both Vapi and Tuner. Confirm the assistant is linked to the trunk (Step 3). Verify the URI format: sip:identifier@sip.vapi.ai.
Agent doesn’t respondEnsure the Vapi assistant has a prompt configured, is active, and not in draft/paused mode.
”Unverified” in TunerRe-enter credentials and click Test Connection again. Check for trailing spaces in the URI or password fields.