Retell AI is the default voice-agent service for the AI Receptionist. VisionScaper has three Retell fields: Retell AI API key, Retell AI webhook secret, and Retell AI phone address (SIP).

• A Retell AI account. Call rates are set by Retell; this guide does not quote them.
• WordPress administrator access.
• Know your webhook address: shown at the top of Settings → VisionScaper AI Receptionist, in the form .../dreamscaper/v1/receptionist/webhook/ENGINE. For Retell, ENGINE is retell.

1. Sign in to the Retell dashboard.
2. Go to Settings (under System), then API Keys.
3. Click Add, name the key, and save. Without Restrict permissions the key has full access; if you restrict it, it must be able to manage agents and make calls (Agent, Call, Phone and History groups). Which exact scopes VisionScaper needs was not verified.
4. Select the key and click Set as Webhook Key. Only one key can be the webhook key.
5. In WordPress go to Settings → VisionScaper AI Receptionist, Keys.
6. Paste the key into Retell AI API key.
7. For Retell AI webhook secret use the secret your Retell setup gives for signing webhooks. VisionScaper checks an HMAC-SHA256 signature in the x-retell-signature header with this value. Which Retell value matches this was not verified in Retell’s docs; check their webhook documentation.
8. Retell AI phone address (SIP): paste the SIP address of your Retell phone number if you use the carrier hand-off. The field name is from VisionScaper; where Retell shows it was not verified.
9. Save. A blank box keeps the saved value.

• Set the webhook address in Retell to the one shown on the VisionScaper screen, with retell at the end.
• Rotate by deleting the key in Retell, creating a new one, and pasting it.

• “The voice service isn’t connected yet”: the API key box is empty.
• Calls happen but nothing logs: the webhook secret or address is wrong.

• https://docs.retellai.com/accounts/manage-api-keys (read 2026-10-15)

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