Can I migrate from Vapi to Open?

Yes. Most of the work is reproducing your prompt, tool list, and routing rules in Open's configuration. The carrier and CRM integrations Open ships save weeks vs. starting from scratch.

Is Open's latency competitive with Vapi?

Median first-token latency under 200ms on US/EU regions. Comparable to Vapi when both run in the same region.

Can Open use my own LLM or voice models?

Yes — voice cloning via ElevenLabs, custom voice training, and bring-your-own-model deployments are supported on enterprise plans.

Is per-minute pricing actually cheaper?

It depends on conversation length. Per-resolution pricing is usually more predictable for business use cases. We're happy to compare on real call samples.

Does Open expose the same kind of API Vapi does?

Yes — agents, tools, calls, transcripts, transfers are all in the API. The Open API is more product-shaped than infrastructure-shaped, but it's complete.

Comparison

Open vs. Vapi

Vapi is voice AI infrastructure; Open is a voice AI product. The right choice depends on whether you want to build the platform or use one.

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Open positioning: Product
Vapi positioning: Platform
Carriers ready (Open): 37+
Tools wired (Open): ~50

01 — Overview

Should I pick Vapi or Open?

It depends on what your team wants to own. Vapi gives you the building blocks; you assemble the agent. Open gives you the agent; you configure it. Both are real options — the answer is about your engineering appetite, not which one is 'better'.

Vapi is a well-engineered voice AI infrastructure platform. It handles the SIP gateway, the LLM orchestration, the TTS/STT, and a clean SDK to wire calls together. Developer teams love it because it's flexible — every part of the call can be customized, every model swapped, every prompt versioned in code. It's a platform you build on.

Open is a product, not a platform. It ships with the SIP layer integrated against 37+ carriers (so you join Twilio, Vonage, RingCentral, Zoom Phone, your trunk — without writing the integration), with ~50 official tool integrations (Salesforce, HubSpot, Zendesk, Stripe, Calendar, Shopify, Slack, Jira), with full observability (recording, transcript, reasoning trace, outcome tags, cost-per-call), with warm SIP REFER transfers, with PII redaction, and with SOC 2 / GDPR / HIPAA / PCI compliance. You configure agents — you don't build the platform underneath.

The right choice depends on the question your team is answering. "How do we get an AI voice agent live on our existing phone system in a week?" — Open is the shorter path. "How do we build a voice AI product as our business?" — Vapi (or Retell, or LiveKit Agents) is the right primitive.

Pricing models also differ in shape. Vapi charges per minute (LLM + TTS + STT + carrier passthrough). Open charges per resolved conversation, with carrier minutes invoiced by your carrier with no markup. For most business use cases (where conversation length varies), per-resolution pricing is more predictable.

Some teams use both: Vapi (or similar) for an experimental or highly-custom agent, Open for the production support / sales / receptionist agents that need to plug into the rest of the business. They're not in fundamental conflict.

Vapi shines at

Maximum flexibility
Every call layer (LLM, TTS, STT, SIP) is swappable. Best for teams that want to own every primitive.
Developer-first SDK
Versioned in code, programmatic agent management, deep customization. Built for engineers, not configurators.
Per-minute pricing
Pay only for the minutes you use, broken down per layer.
Lower-level control
Direct access to the audio pipeline, prompt context, and model parameters.

Open ships with

Carrier integrations done
37+ carriers (Twilio, Vonage, RingCentral, Zoom Phone, Avaya, Mitel, BT, Verizon, Orange, etc.) as first-class SIP destinations.
Tool integrations done
~50 official integrations (Salesforce, HubSpot, Zendesk, Stripe, Calendar, Shopify, Slack, Jira). No SDK assembly.
Observability and compliance done
Recording, transcripts, reasoning traces, PII redaction, SOC 2 / HIPAA / PCI. Included, not bolted on.
Per-resolution pricing
Pay per resolved conversation, not per minute. Carrier minutes stay billed by your carrier.

02 — Why it works

What makes Open the right comparison answer

For business buyers, Open is faster to value
Days to production with your existing carrier and CRM, not quarters of platform engineering.
For platform builders, Vapi is more flexible
If your business is voice AI, you want the primitives Vapi exposes.
They aren't mutually exclusive
Some teams run Vapi for experimental agents and Open for the production ones tied to the rest of the business.
Pricing matches positioning
Vapi: per minute, layer by layer. Open: per resolved conversation, predictable per-call cost.

03 — Security

Encrypted, audited, refundable

SIP over TLS for signaling, SRTP for media. Every call logged with full reasoning traces. SOC 2 Type II, GDPR-aligned, HIPAA- and PCI-ready. Backed by the Open $2M Refund Guarantee.

04 — FAQ

Open vs. Vapi questions, answered

More voice AI guides

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