# Voice Agents The **Voice agent** conducts real-time AI phone conversations with leads — handling incoming sales calls and making outgoing follow-up calls. Voice agents engage leads immediately, 24/7, without requiring a human rep on every call.

The Voice Agent Editor showing the Instructions, Abilities, and Configuration tabs.

## Use cases ### Outgoing follow-up calls Spara can call leads automatically when they complete — or fail to complete — a key action. A common example: a lead submits a marketing form but never schedules a meeting. Spara calls immediately to move them through the next step while interest is high. Outgoing calls are triggered through [Workflows](/agents/workflows.md) using the [Call Phone Step](/agents/workflows/call-phone.md). ### Incoming calls Spara handles incoming sales calls end-to-end — answering questions, qualifying leads, and booking meetings. When a lead calls your assigned phone number, the Voice agent answers immediately, identifies the caller if possible, and conducts the conversation using the lead's available context (fields, conversation history, and CRM data). *** ## Abilities Abilities are tools the agent can invoke during a live call. They are configured on the **Abilities** tab of the Voice Agent Editor. | Ability | Description | | ---------------- | ------------------------------------------------------------------------------------------------------- | | **Book meeting** | The agent checks your calendar, reads available slots aloud, and books the meeting through conversation | | **Transfer** | Cold or warm transfer to a rep or team when the lead is qualified and ready to speak with someone | | **API request** | Call an external API endpoint during a call — for order lookups, inventory checks, or internal data | ### Book meeting Voice agents book meetings through conversation — not by showing a calendar widget. The flow works like this: 1. The agent asks the lead when they're available and checks your calendar for open slots 2. The agent reads the available times aloud (e.g., "I have Tuesday at 2pm or Wednesday at 10am") 3. The lead picks a time 4. The agent confirms the details (name, email) and books the meeting The agent can filter slots by time of day based on the lead's preferences. Requires a [Calendar Integrations](/integrations/calendar-integrations.md) — Spara supports [Cal.com](/integrations/calendar-integrations/cal.com.md), [Calendly](/integrations/calendar-integrations/calendly.md), and other providers. ### Transfer Voice agents can transfer calls to a rep or team when the moment is right — for example, when a lead is qualified and ready to speak with sales. * **Cold transfer** — The agent says goodbye and forwards the call. The lead hears ringing and connects with the rep (or voicemail). Use this for general routing. * **Warm transfer** — The agent connects your rep first, provides context about the conversation, then drops off. The lead stays on the line throughout. Use this for high-value leads who benefit from a personal handoff. Both transfer types support multiple named destinations (e.g., "Sales", "Support", a specific rep), so the agent can route to the right team based on the conversation. ### API request Voice agents can make HTTP requests to external services during a call. For example, the agent could look up an order status, check inventory, or query your internal systems. You configure the URL and parameters ahead of time — the agent triggers the request at the right moment in the conversation. *** ## Configuration Voice agents are configured through the Agent Editor — the same split-screen interface used for Chat, Email, and Text agents. The **Instructions** tab defines the agent's persona, tone, and how it handles common scenarios. The **Configuration** tab covers phone number assignment and call behavior. For a step-by-step walkthrough, see [https://docs.spara.com/guides/setting-up-voice-agents](https://docs.spara.com/guides/setting-up-voice-agents "mention"). ### Phone number setup Each voice agent can be assigned a phone number on the **Configuration** tab. This is the number the agent answers incoming calls on and uses as the caller ID for outgoing calls. Each phone number can only be assigned to one published voice agent at a time. {% hint style="info" %} Spara does not make cold or unsolicited outgoing calls to leads outside of your [Workflows](/agents/workflows.md). {% endhint %} ### Voice and call settings * **Voice** — Pick a voice that matches your brand. You can fine-tune speed, stability, and similarity. * **Voicemail** — Enable the agent to leave a scripted voicemail when a lead doesn't answer an outgoing call. * **Interruption handling** — Control whether the lead can interrupt the agent mid-sentence, and how sensitive the detection is. * **Re-engagement** — When enabled, the agent speaks again if the lead goes silent, keeping the conversation moving. * **Max call duration** — Set a time limit for calls. Defaults to 10 minutes if not set. ### Pronunciations On the [**Voice > Configuration**](https://app.spara.co/settings/voice/configuration) tab, you can add custom pronunciations that apply to all Voice agents in your account. Each entry maps a word to how it should be spoken — for example, "SQL" → "S.Q.L." or your company name to its correct pronunciation. ### Do Not Call Spara automatically prevents outgoing calls to leads who have opted out. When a lead requests not to be called during a voice conversation, the Voice agent records this preference. Once marked as Do Not Call, no outgoing calls will be placed to their number — including calls triggered by [Workflows](/agents/workflows.md). {% hint style="warning" %} Do Not Call preferences are tracked per phone number within your account. If a lead opts out, all Voice agents in your account will respect that preference. {% endhint %} *** ## FAQ ### How does calendar booking work on voice calls? The agent reads available slots aloud and books the meeting through conversation. It does not show a calendar widget — the entire flow is verbal. See [#book-meeting](#book-meeting "mention") above for details. ### How do transfers work? Transfers are configured as named destinations in the Abilities tab. Cold transfer forwards the call directly; warm transfer brings your rep onto the line first before dropping off. See [#transfer](#transfer "mention") above. ### Can Voice agents leave voicemails? Yes. If a lead doesn't answer an outgoing call, the Voice agent can leave a voicemail using a script you configure in the agent's settings under **Voice and call settings**. ### Where do I see call outcomes? Call results appear on the lead's timeline in [Leads](/platform/leads.md) — including whether the call was answered, transferred, or resulted in a booked meeting. You can use these outcomes as [Workflows](/agents/workflows.md) triggers and conditions. ### Does the Voice agent know about the lead before the call? Yes. If the lead has existing fields — from a CRM sync, prior chat conversation, or previous calls — the Voice agent has access to that context. This includes data from [Salesforce](/integrations/crm-integrations/salesforce.md) and [Hubspot (CRM)](/integrations/crm-integrations/hubspot-crm.md) integrations. ### Are voice calls recorded? Yes. All voice calls are recorded and transcribed. You can play back recordings and review transcripts from the lead's timeline on the [Leads](/platform/leads.md) page. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.spara.com/agents/voice-agents.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.