CallSprout + Vapi
Run the voice agent your developers built on Vapi on CallSprout's phone system, inbound and outbound, with warm transfers to the people on your team. Available for Vapi.
The Vapi integration features described on this page require an active, permitted connection to Vapi. Availability depends on that system's supported APIs and permissions.
How CallSprout works with Vapi.
Vapi is built for developers. Your team picks the language model, the voice and the speech engine, writes the agent's logic, and connects it to outside tools through function calls or MCP. That flexibility is the reason teams choose it. What Vapi does not try to be is your company's phone system.
CallSprout fills that gap. We connect your Vapi agent to your CallSprout phone system over SIP, so the agent answers calls on your CallSprout numbers and places outbound calls through them. Vapi handles the conversation. CallSprout handles the numbers, the routing and the people who take over when the agent hands a call off.
Bring-your-own-agent connections are in early access, and we set each one up with you. If your team would rather not build and maintain an agent, Sage, CallSprout's AI voice agent, comes with the platform. The connect your tools page explains both paths.
CallSprout and Vapi, working together.
What Sage does once your call data flows into the tools you already use.
Keep every choice your developers made in Vapi: the model, the voice, the prompt and the tool calls. CallSprout carries the call and does not change how the agent behaves.
The agent answers inbound calls you route to it and places outbound calls through CallSprout over SIP, from the business numbers your customers already recognize.
When the agent needs a person, it can brief them before the caller joins, then hand the call to an extension, ring group or queue on CallSprout.
Function calls and MCP connections run from your Vapi agent as they do today. If a tool you need has no MCP server yet, we can build one.
Built by developers, carried by a real phone system
A Vapi agent is code and configuration your team owns. CallSprout does not ask you to rebuild it. We set up a SIP connection between your CallSprout account and your Vapi account, point the numbers you choose at the agent, and set up the path back to your team for transfers.
Your Vapi agent can use its own tools to look up an order or create a ticket in your help desk during the conversation. Those calls go from Vapi to your systems directly, the way you configured them. If one of your tools already has an MCP server, the agent can connect to it. If it doesn't, we can build one for that tool.
Routing stays in CallSprout's call flows. You decide whether the agent takes the main line, only after-hours calls, or one department's number, and you can change that without redeploying the agent.
Warm transfers and hand-offs
Vapi supports warm transfers, where the agent speaks to the person receiving the call before the caller is connected. Over a SIP connection, how a transfer behaves depends on how the agent and the connection are configured, so we choose the transfer method with you and test it before going live.
Transfers land on CallSprout extensions, ring groups or queues. The person who picks up is on the CallSprout desk phone, desktop app or mobile app they use every day, with no separate tool to watch.
What early access means
We configure each bring-your-own-agent connection by hand. On a short call we review your Vapi setup, the numbers involved and your transfer targets. Then we build the connection, test calls in both directions, and confirm transfers work the way your team expects.
Your Vapi account, its usage and its billing stay yours. CallSprout provides the phone system, the numbers and the team on the other end of a transfer.
What this looks like day to day.
Your developers built a Vapi agent that answers product questions. It takes the main support number on CallSprout and warm transfers billing questions to the accounts queue with a short briefing first.
The agent places follow-up calls through CallSprout so customers see a number they know. When someone wants a person, the agent transfers them to the sales ring group.
Your team routes a single CallSprout number to a new Vapi agent while the main line keeps its current call flow. When the agent is ready, you widen the routing in CallSprout.
Getting connected to Vapi.
- 1
Book a 15-minute call with our team to walk through your Vapi agent, the numbers it should handle, and where warm transfers should land.
- 2
We set up the SIP connection between CallSprout and your Vapi account, then test inbound calls, outbound calls and transfers with you.
- 3
When everything checks out, your chosen numbers route to the agent and hand-offs reach your team on CallSprout phones. Book your call to get started.
Have Sage call you.
The fastest way to see how Sage handles your calls is to hear it. Leave your number and Sage, our AI voice agent, calls you in about 10 seconds.
Vapi, answered.
- Does CallSprout work with Vapi?
- Yes. CallSprout connects to Vapi over SIP, so your Vapi agent can answer inbound calls on CallSprout numbers and place outbound calls through CallSprout. The connection is in early access, and we set it up with you.
- Can I keep my own models and voices?
- Yes. Model, voice and speech choices are made in your Vapi account and stay there. CallSprout carries the call and does not change the agent's configuration.
- Does the Vapi agent support warm transfers to my team?
- Yes. Vapi supports warm transfers, and the agent can hand calls to extensions, ring groups or queues on CallSprout. Transfer behavior over SIP depends on configuration, so we pick the method with you and test it during setup.
- Can my Vapi agent use MCP?
- Yes. Vapi agents can connect to MCP servers. If your tools already have one, the agent can use it. If they don't, we can build one for you.
- Do I need my own Vapi account?
- Yes. The agent and its usage live in your Vapi account under Vapi's terms and billing. CallSprout provides the phone system the agent runs on.
If your developers are stretched thin, our sister company Ereos builds custom AI for small and growing businesses on its Watchtower platform, including agents and tools built around your own data.
When you need AI shaped around your business
CallSprout gives your Vapi agent a phone system to run on. When you need AI designed around your own records and workflows and do not have the developer time, that is what our sister company Ereos builds. Its Watchtower platform connects to the tools your business already runs.
Schedule a discovery call with EreosConnect CallSprout to Vapi
Book a 15 minute call and we will get you set up.