> For the complete documentation index, see [llms.txt](https://docs.spara.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.spara.com/agents/capabilities/phone.md). # Phone The **Phone capability** conducts real-time AI phone conversations with leads, handling incoming sales calls and making outgoing follow-up calls. It engages leads immediately, 24/7, without requiring a human rep on every call. For live, voice-narrated product walkthroughs with synchronized visuals, see the separate [Product Demo](/agents/capabilities/product-demo.md) capability.

A Phone capability's Configuration tab: phone number, call settings, and voice.

## 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/steps/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 Phone capability answers immediately, identifies the caller if possible, and conducts the conversation using the lead's available context (fields, conversation history, and CRM data). ### Callback on outgoing numbers All outgoing phone numbers automatically accept incoming calls. If a lead misses your outgoing call and calls the number back, the same Phone capability that was dispatched picks up and continues the conversation with the lead's full context intact. No additional configuration is required; this behavior is enabled by default on all outgoing numbers. *** ## Phone number management Phone numbers are managed centrally in your account's settings and then assigned to individual capabilities or workflows. ### Adding phone numbers Navigate to **Settings > Voice > Configuration** to view and manage your account's phone numbers. From here you can register new numbers that become available across your account for use with Phone capabilities, [SMS](/agents/capabilities/sms.md), and workflows. Each phone number can serve as: * **An incoming number for a Phone capability.** Assign it on the capability's Configuration tab. Leads who call that number reach this capability. * **An incoming number for an** [SMS](/agents/capabilities/sms.md)**.** Assign it on the SMS capability's Configuration tab. * **An outgoing number for workflows.** Select it in a [Call Phone Step](/agents/workflows/steps/call-phone.md) or [Send Text Step](/agents/workflows/steps/send-text.md) step. ### Phone number ownership Phone numbers used by Spara are hosted in Spara's telephony account. There are two common ways to get a number live: * **Spara provisions a new number for you.** The most common path. Spara registers a fresh number in the country and area code you choose. * **You port an existing number into Spara.** If you already own a phone number and want to keep it, you can transfer it into Spara's telephony account. Spara coordinates the port with your current provider. {% hint style="info" %} Bring-your-own-number (where you retain ownership of the number and Spara routes calls from your carrier directly) is on the Spara roadmap but is not currently under development. Today, the number must live in Spara's telephony account. {% endhint %} ### Connecting your phone numbers to Spara If you want a phone number you already publish on your website or marketing materials to reach a Spara Phone capability, there are two ways to wire it up. **Option 1: Forward calls to a Spara-provided number.** The simplest path. Configure your existing phone system to forward incoming calls to a number Spara has provisioned for you. From your customers' perspective they dial the same number they always have; behind the scenes the call forwards to Spara and the Phone capability picks up. This works with any phone system that supports call forwarding to an external number. No technical integration required; your Spara representative can help you set this up. **Option 2: Route calls directly to Spara over SIP.** If your phone system supports SIP (Session Initiation Protocol) — common in business telephony platforms like Genesys, RingCentral, and similar — you can route incoming calls straight to Spara's SIP endpoint, skipping the intermediate forward. This option is more efficient (one less hop) but requires technical coordination. Spara needs to share its SIP endpoint with your telephony team and allow-list your routing IPs. Expect a brief technical setup session between your team and Spara to get this working. Most customers use Option 1 because it requires no engineering effort. Choose Option 2 when your telephony stack already speaks SIP and you want a tighter integration. ### Assigning numbers Each Phone capability can be assigned a phone number on the **Configuration** tab. This is the number it answers incoming calls on and uses as the caller ID for outgoing calls. Each phone number can only be assigned to one published Phone capability at a time. You can run multiple Phone capabilities on separate phone numbers. For example, one number for sales inquiries and another for support routing. Each operates independently with its own instructions, abilities, and phone number. {% hint style="info" %} Spara does not make cold or unsolicited outgoing calls to leads outside of your [Workflows](/agents/workflows.md). {% endhint %} ### Branded caller ID for outgoing calls Branded caller ID displays your business name (instead of just a phone number) on the lead's screen when an outgoing call rings, which significantly improves answer rates. Spara handles the registration with the telephony network on your behalf, but it requires information from you (business name, use case, sample call scripts) and **typically takes several days to complete**. Whether carriers flag your outgoing calls as "Potential Spam" depends primarily on the carrier verifications Twilio requires: A2P 10DLC for SMS-paired numbers, business identity verification, and similar registrations. Branded calling is an additional layer on top of those verifications. It is not, on its own, what prevents the spam label. Completing the required Twilio verifications is the prerequisite; branded calling then improves how your number presents on the recipient's screen. {% hint style="warning" %} If you plan to use a Phone capability for outgoing calls, ask your Spara account team to kick off the required carrier verifications and branded-calling onboarding as early as possible. Calls placed before verifications complete may show as "Potential Spam" on the recipient's phone, which materially hurts answer rates. {% endhint %} *** ## Abilities Abilities are tools the capability can use during a live call. They are configured on the **Abilities** tab. For a cross-channel overview, see [Abilities](/agents/capabilities/configuring/abilities.md). | Ability | Description | | ---------------- | -------------------------------------------------------------------------------------------------- | | **Book meeting** | 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 The Phone capability books meetings through conversation, not by showing a calendar widget. The flow works like this: 1. It asks the lead when they're available and checks your calendar for open slots 2. It reads the available times aloud (e.g., "I have Tuesday at 2pm or Wednesday at 10am") 3. The lead picks a time 4. It confirms the details (name, email) and books the meeting It can filter slots by time of day based on the lead's preferences (morning vs. afternoon, weekdays only, etc.). Booking requires a [Calendar Integrations](/integrations/calendar-integrations.md) connection. Spara supports [Cal.com](/integrations/calendar-integrations/cal.com.md), [Calendly](/integrations/calendar-integrations/calendly.md), and others. {% hint style="info" %} When you create a new Phone capability, Spara automatically creates a Calendly calendar integration for it. You can change the calendar provider or customize the integration on the Abilities tab. {% endhint %} ### Transfer The Phone capability 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 vs warm transfer * **Cold transfer.** It says goodbye and forwards the call. The lead hears ringing and connects with the rep (or voicemail). If nobody picks up, the call ends. Use this for general routing where the receiving team is reliably staffed. * **Warm transfer.** It connects your rep first, briefs them on the conversation, then drops off. The lead stays on the line throughout. **If nobody picks up the warm transfer, the Phone capability stays on the call with the lead**: it can continue answering questions, capture follow-up details, or end gracefully rather than dropping the caller. Use this for high-value leads where a missed handoff would be costly. Spara recommends warm transfers by default. The recovery behavior (staying on if the handoff misses) keeps the lead engaged even when your rep is unavailable. #### Transfer destination types You can configure multiple named destinations (e.g., "Sales", "Support", a specific rep) on the Abilities tab. The capability chooses the right destination based on the conversation and your instructions. Each destination can be one of two types: * **A phone number.** A standard phone number, whether a rep's cell phone, a desk line, or a routing number at another service. Phone-number transfers work out of the box; no extra setup needed. * **A SIP endpoint.** A SIP address belonging to another voice system (such as your support center's SIP-based platform). SIP transfers require a brief technical setup session between Spara and the receiving system so they accept calls from us. Use this only when your downstream system explicitly requires it. If you're unsure which type a destination is, ask the team running that destination "is this a phone number or a SIP endpoint?" The answer determines whether the setup is plug-and-play or requires a coordination call. ### API request The Phone capability can make HTTP requests to external services during a call, for example, to look up a lead's account status or pull pricing details for the service they're asking about. You configure the URL, HTTP method, any required headers, query parameters, and a request body ahead of time. It triggers the request at the right moment in the conversation and reads the response. *** ## Configuration The [AI Instructions](/agents/capabilities/configuring/ai-instructions.md) tab defines the capability's persona, tone, and how it handles common scenarios. The **Configuration** tab covers phone number assignment, voice selection, 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"). ### Voice and call settings * **Voice provider.** Choose from supported text-to-speech providers, including ElevenLabs. Each provider offers a different range of voices and characteristics. * **Voice.** Pick a voice that matches your brand. Depending on the provider, you can fine-tune characteristics like speed, stability, and similarity to control how natural and consistent it sounds. Customers often try a handful of voices on test calls before settling on one; the right voice has a noticeable impact on perceived quality. * **Voicemail.** Leave a scripted voicemail when a lead doesn't answer an outgoing call. * **Interruption handling.** Control whether the lead can interrupt mid-sentence, and how sensitive the detection is. More sensitive settings feel more conversational but can cause it to stop talking when the lead is just acknowledging ("uh-huh"). Less sensitive settings feel more steady but can sound robotic. * **Re-engagement.** When enabled, it speaks again if the lead goes silent, keeping the conversation moving. Useful for keeping momentum on calls where the lead is distracted. * **Max call duration.** Optionally set a time limit for calls. If a limit is set, it wraps up gracefully as the limit approaches, then the call ends. If you leave this unset, calls run as long as the conversation does. ### Privacy warning Configure a custom call recording or privacy disclosure that plays at the start of each call before the conversation begins. You can customize the warning text to meet local compliance requirements, and select a specific voice for the disclosure that's different from the main voice. For outgoing calls, you can also embed the disclosure directly in the instructions instead of using this toggle. See [#how-do-i-handle-the-recording-disclosure-on-outgoing-calls](#how-do-i-handle-the-recording-disclosure-on-outgoing-calls "mention") for both options. ### Pronunciations On the [**Voice > Configuration**](https://app.spara.co/settings/voice/configuration) tab, you can add custom pronunciations that apply to all Phone capabilities 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. ### Publishing and version history When you publish, the current draft becomes the live version. Spara tracks every published version in version history, so you can see what changed and when. This is useful for auditing prompt changes, rolling back if something breaks, and coordinating updates across your team. See [Saving & Publishing](/agents/capabilities/configuring/saving-and-publishing.md) for details on the draft/publish workflow. ### Do Not Call Spara automatically prevents outgoing calls to leads who have opted out. When a lead requests not to be called during a conversation, the Phone capability 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). [Call Phone Step](/agents/workflows/steps/call-phone.md) steps in a workflow are skipped for opted-out leads, and the workflow continues to the next step. Leads with an active Do Not Call preference are marked with a visible badge on the [Leads](/platform/leads.md) page, so your team can see at a glance which leads have opted out. *** ## Voice events in webhooks When a voice call ends, Spara emits a `lead.updated` webhook with `source: "voice"`. Voice calls appear in a `calls` array on the payload (one entry per call) with start/end timestamps, whether it was incoming or outgoing, the Phone capability that handled the call, a short summary, and the transcript. See [https://docs.spara.com/developers/spara-api/webhooks](https://docs.spara.com/developers/spara-api/webhooks "mention") for the full webhook payload spec. *** ## A/B testing You can run two variants of a Phone capability (different prompts, voices, or abilities) in parallel and compare outcomes. Variants are grouped by the phone number they share, and traffic is split between them. See [A/B Testing](/agents/capabilities/configuring/a-b-testing.md) for how to create variants and set the traffic split. *** ## Ask Spara AI The [Ask Spara AI](/agents/capabilities/configuring/ask-spara-ai.md) tab lets you chat with an AI assistant about the capability's behavior. Use it to debug why it said something unexpected, understand how your instructions are being interpreted, or get suggestions for improving your prompt. This is the fastest way to diagnose issues without re-reading your full instruction set. *** ## Testing Click **Test** to start a test web call directly in your browser. This lets you have a live conversation to verify it sounds right. You can also test outgoing calls from the voice testing dashboard. This sends a real outgoing call to a phone number you specify, letting you experience the call exactly as a lead would, including caller ID, voicemail behavior, and the full call flow. Test calls use the **draft** version; any unpublished changes will be reflected. This means you can iterate on your prompt and abilities without affecting live calls. Test calls are recorded and appear in the call history for review. See [Testing](/agents/capabilities/configuring/testing.md) for more details. *** ## FAQ ### How does calendar booking work on voice calls? The capability reads available slots aloud and books the meeting through conversation. It does not show a calendar widget; the entire flow is verbal. When you create a new Phone capability, a Calendly integration is automatically set up. You can change the provider or customize it on the Abilities tab. See [#book-meeting](#book-meeting "mention") above for details. ### How do transfers work? Configure one or more named destinations (e.g., "Sales", "Support") on the Abilities tab. Cold transfer forwards the call directly; warm transfer brings your rep onto the line first, where it gives them a short verbal summary of the conversation before dropping off. It picks the destination based on your instructions and the conversation. See [#transfer](#transfer "mention") above. ### Can I have multiple Phone capabilities on different phone numbers? Yes. Register multiple phone numbers in **Settings > Voice > Configuration**, then assign each number to a different Phone capability on its Configuration tab. For example, you could run a sales qualification capability on one number and a support routing capability on another. Each phone number can only be assigned to one published Phone capability at a time. ### Can it leave voicemails? Yes. If a lead doesn't answer an outgoing call, the Phone capability can leave a voicemail using a script you configure under **Voice and call settings**. ### What happens if a lead calls back an outgoing number? The same Phone capability that placed the outgoing call automatically answers. It has the lead's full context from the original call attempt, so the conversation picks up naturally. ### 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 it 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 Phone capability 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. The privacy warning plays at the start of the recording. See [#privacy-warning](#privacy-warning "mention") to customize it. ### How do I set up the privacy warning? Go to the **Configuration** tab and find the privacy warning section under Voice and call settings. Enter your custom disclosure message and optionally select a different voice for the warning. The disclosure plays automatically at the start of each call before the conversation begins. ### How do I handle the recording disclosure on outgoing calls? You have two options, and you can choose whichever feels more natural for your use case: * **Use the privacy warning toggle.** A consistent pre-recorded disclosure plays at the start of every call, regardless of direction. The advantage is consistency and a clear separation between the disclosure and the conversation; you can even use a different voice for the warning. * **Embed the disclosure in your instructions.** Have the capability say it as part of the opening greeting, for example: *"Hi, this is Jenna from Acme. Please note this call may be recorded for quality purposes. I'm calling because…"* The advantage is a more conversational feel on outgoing calls, where some recipients are more likely to stay engaged when the disclosure flows naturally with the greeting rather than playing as a separate prompt. Both approaches satisfy the compliance requirement that the disclosure be delivered at the start of the call. Pick the one that fits your brand, and whichever you choose, make sure every recorded call includes the disclosure in some form. ### What happens when the call hits the time limit? If you've set a max call duration, it wraps up gracefully as the limit approaches and the call ends when it hits. You can also leave the limit unset, in which case calls run as long as the conversation does. See **Max call duration** under [#voice-and-call-settings](#voice-and-call-settings "mention"). ### What happens for incoming calls outside business hours? Spara doesn't currently offer a platform-wide business hours setting, but the capability can behave differently depending on the time of day. For example, if a lead calls outside your hours, you can instruct it to skip the live transfer and instead book a meeting with a rep through the calendar. It has access to the current time and timezone and can branch on it. ### Can the Phone capability send SMS or text messages? Not directly. To follow up by text, use a workflow with a [Send Text Step](/agents/workflows/steps/send-text.md) step. Outgoing SMS requires Twilio A2P registration; your Spara account team can guide you through the registration process. ### Will Spara reuse the same lead record when the same phone number calls back? Yes. Spara associates calls from the same phone number with the same lead, so conversation history, captured fields, and CRM context carry across repeat calls instead of creating duplicates. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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/capabilities/phone.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.