Integrations

Retell

Test an existing Retell agent with no code. RubricHQ connects to your Retell account, starts a web call to your agent, and runs your scenario against it — and can also pull the agent’s config and auto-import production calls for observability.

This is an external-provider agent: the bot lives in Retell, and RubricHQ reaches it over Retell’s own transport.

1. Connect Retell (once per workspace)

Settings → Integrations → Retell → paste your API key. It’s stored encrypted and reused by every agent on Retell.

You can also connect inline from the agent screen when you pick the provider.

2. Configure the agent

On the agent’s Configuration tab, choose Agent Type → Retell and set the Agent ID (e.g. agent_xxxx…). The ID field unlocks once Retell is connected for the workspace.

3. Instructions: Sync from vendor or Paste

Two mutually-exclusive options (buttons appear once the provider + Agent ID are set):

Sync instructions from vendor

Pulls the latest config straight from Retell and fills the agent:

1{
2  "instructions":  "<the agent's system prompt>",
3  "first_message": { "type": "assistant-waits-for-user", "message": "" },
4  "language":      "en-US",
5  "phone_number":  "+15722238368"
6}
  • Instructions — the system prompt, used to generate scenarios and suggest prompt improvements.
  • Opening prompt — derived from how your agent starts (speaks first vs waits), so our caller adapts.
  • Primary language — matched to a supported language (locale-tolerant, e.g. en ↔ en-US).
  • Phone number — see the note below.

For Retell, the phone number isn’t on the agent object — RubricHQ looks it up from your Retell phone numbers and matches the one linked to this agent (inbound/outbound).

Paste instructions

Define the opening prompt and instructions yourself (just like a self-managed agent), and set primary language + phone number directly. Choosing this disables instruction auto-sync so Retell never overwrites what you typed.

4. Auto-sync (optional)

Two independent toggles under the agent’s external-provider settings:

ToggleWhat it does
Sync instructionsRe-pulls the Retell agent config on a fixed 24h cadence (disabled when you’re pasting instructions).
Fetch callsImports the agent’s production calls into RubricHQ observability on your chosen interval, with a configurable minimum call duration filter.

Imported calls get the full observability treatment — transcript, recording, and standard metrics — alongside your test runs.

5. How a test run works

When you run a scenario/batch against a Retell agent:

  1. RubricHQ starts a web call to your agent through the Retell API.
  2. Our AI caller runs your scenario; we auto-detect whether your agent speaks first and adapt the opening.
  3. The call is recorded; transcript metrics and (where audio is available) audio metrics are computed.

No endpoints to implement on your side — Retell hosts the bot, RubricHQ drives the caller.

Results

Each run shows the transcript, recording, call metadata (end reason, cost, vendor summary, success/sentiment, structured data when present), and metrics. Auto-fetched production calls appear in Observability → Conversations for the agent.

Use Retell when the agent already lives in Retell. For Vapi assistants see Vapi; to run your own bot in a LiveKit or Daily room (e.g. Pipecat) see LiveKit or Daily.