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# Voice agent platforms, runtimes and model routers
A hosted voice agent platform, an agent runtime and a voice model router are not interchangeable. The platform manages more of the deployed agent. The runtime owns the realtime conversation loop. The model router selects or pins model APIs. Compare products only after choosing which boundary the team intends to own.
Short answer
Vapi, Retell AI and Bland AI are hosted products. Pipecat is a runtime framework. Speko Router is a model layer for STT, LLM and TTS calls.
Author
Speko engineering
Reviewed by
Speko engineering
Published
August 2, 2026
Last reviewed
August 2, 2026
## Comparison matrix
Competitor category and billing statements were checked against official sources on July 31, 2026; Pipecat was checked on July 31, 2026. The matrix compares product boundaries, not overall quality. Follow the source before making a purchasing decision.
| Option | Scope | Telephony | Provider choice and routing | Runtime ownership | Observability and failover | Pricing model | Sources |
| --- | --- | --- | --- | --- | --- | --- | --- |
| [Speko Router](#speko) Voice model router | Compatible model calls for STT, LLM and TTS. It does not run the conversation loop. | Not included in the Router boundary. Telephony and WebRTC remain with the application runtime. | The application can pin a model or request measured automatic selection from eligible routes. | Speko operates the routing API; the customer keeps LiveKit, Pipecat or a custom runtime. | Route, reason, failover-count and first-byte headers. Failover is pre-response only, not mid-stream. | Router markup or an infrastructure rate; current terms are kept on the pricing page. | [Speko infrastructure guide](https://speko.ai/voice-agent-infrastructure/) [Speko pricing](https://speko.ai/pricing/) Checked 2026-08-02 |
| [Vapi](#vapi) Hosted developer platform for voice agents | Managed agent orchestration with prompts, tools and a provider stack configured in the platform. | Telephony is connected and billed separately from Vapi hosting and orchestration. | Developers configure supported STT, LLM and TTS choices. Model usage can be pass-through or BYOK. | Vapi operates the hosted platform; the customer configures the agent and connected services. | The platform owns call logs and orchestration. Fallback behavior stays within the configured provider paths. | Usage-based hosting and orchestration, plus model and telephony charges; BYOK providers can bill directly. | [Vapi pricing](https://vapi.ai/pricing) [Vapi pricing FAQ](https://docs.vapi.ai/faq) [Vapi documentation](https://docs.vapi.ai/) Checked 2026-07-31 |
| [Retell AI](#retell) Hosted phone-agent platform | Managed phone agents assembled from Retell-supported infrastructure and model components. | Published options include Retell carrier service and custom SIP, priced as separate components. | The agent uses model and infrastructure choices supported by the Retell configuration surface. | Retell operates the phone-agent platform and runtime; the customer configures the agent. | Call operations and logs are platform-managed within the supported component boundary. | Component pricing: voice infrastructure plus selected TTS, LLM, telephony and optional features. | [Retell AI pricing](https://www.retellai.com/pricing) [Retell AI documentation](https://docs.retellai.com/) Checked 2026-07-31 |
| [Bland AI](#bland) Hosted phone automation platform | Managed phone-call automation, including campaign and call execution inside the Bland product. | Bland supports its own telephony and BYOT. Carrier, transfer and some outbound charges can be separate from connected-minute usage. | STT, LLM and TTS are integrated into the connected-minute product rather than exposed as a neutral router. | Bland operates the phone automation stack; the customer configures workflows and integrations. | Call execution and logs are platform-managed inside the phone automation boundary. | Tiered monthly plans plus connected-minute usage. Carrier, BYOT, transfer and some outbound charges can add telephony cost. | [Bland AI pricing](https://www.bland.ai/pricing) [Bland AI billing](https://docs.bland.ai/platform/billing) [Bland AI documentation](https://docs.bland.ai/) Checked 2026-07-31 |
| [Pipecat](#pipecat) Open-source framework with an optional managed cloud | Pipecat is a code framework for realtime pipelines; Pipecat Cloud is a separate managed deployment service. | A self-hosted application selects its transport or telephony integration. Pipecat Cloud offers managed deployment around Pipecat workloads. | Developers wire individual STT, LLM and TTS services in code, or point those services at an external router. | The application team owns a self-hosted Pipecat runtime. Pipecat Cloud manages deployment infrastructure, scaling, operations and monitoring for hosted workloads. | Self-hosted teams own runtime operations; Pipecat Cloud provides a managed operational layer. Model-service behavior still depends on the configured services. | The framework is open source. Self-hosted model, transport and hosting costs are separate; Pipecat Cloud is a separately priced managed service. | [Pipecat documentation](https://docs.pipecat.ai/) [Pipecat Cloud documentation](https://docs.pipecat.ai/pipecat-cloud/introduction) [Pipecat repository](https://github.com/pipecat-ai/pipecat) Checked 2026-07-31 |
## What Speko Router replaces
Speko replaces separate compatible model clients and application-owned selection policy. It does not replace the phone carrier, media transport, turn detector, context, tools or deployment runtime.
Current Router evidence
- [Speko infrastructure guide](https://speko.ai/voice-agent-infrastructure/)
- [Speko pricing](https://speko.ai/pricing/)
- [Current model catalog](https://speko.ai/models/)
## Competitor-specific tradeoffs
### Speko vs Vapi
Managed agent orchestration with prompts, tools and a provider stack configured in the platform.
Strengths of this option
- Developer-facing managed agent surface
- Configurable provider stack
- Platform owns more of deployment and call orchestration than a model router
Watch-outs
- The bill spans platform, model and telephony components
- Provider compatibility and fallback coverage depend on the current platform configuration
- Moving to or from a hosted agent abstraction is a wider change than swapping a model API
When to choose it
Choose Vapi when a managed developer platform should own agent orchestration and provider configuration.
Official sources
[Vapi pricing](https://vapi.ai/pricing) [Vapi pricing FAQ](https://docs.vapi.ai/faq) [Vapi documentation](https://docs.vapi.ai/)
Last checked 2026-07-31
### Speko vs Retell AI
Managed phone agents assembled from Retell-supported infrastructure and model components.
Strengths of this option
- Managed phone-agent product
- Component-based configuration and pricing surface
- Telephony and agent operations live in one hosted workflow
Watch-outs
- The final rate depends on the selected model, telephony and optional components
- Provider choice is bounded by the platform-supported combinations
- A platform-managed runtime offers less code-level control than owning the loop
When to choose it
Choose Retell when the requirement is a managed phone-agent product rather than a standalone model-routing API.
Official sources
[Retell AI pricing](https://www.retellai.com/pricing) [Retell AI documentation](https://docs.retellai.com/)
Last checked 2026-07-31
### Speko vs Bland AI
Managed phone-call automation, including campaign and call execution inside the Bland product.
Strengths of this option
- Phone-automation product boundary
- Managed campaign and call execution
- Integrated model components reduce the number of services the application wires directly
Watch-outs
- The product boundary is phone automation, not a provider-neutral model API
- Monthly tier, connected-minute, carrier, BYOT and applicable transfer or outbound charges must be compared together
- Model-level control is bounded by the platform surface
When to choose it
Choose Bland when the managed phone automation workflow is the product requirement.
Official sources
[Bland AI pricing](https://www.bland.ai/pricing) [Bland AI billing](https://docs.bland.ai/platform/billing) [Bland AI documentation](https://docs.bland.ai/)
Last checked 2026-07-31
### Speko vs Pipecat
Pipecat is a code framework for realtime pipelines; Pipecat Cloud is a separate managed deployment service.
Strengths of this option
- Code-level control of the realtime pipeline
- Open-source framework and service ecosystem
- Can use direct providers or an external model router
Watch-outs
- Self-hosting leaves deployment, scaling and operational monitoring with the team
- Provider setup and cross-service policy live in application code
- Hosting and provider costs remain separate
When to choose it
Choose Pipecat for code-level control of the realtime conversation loop; choose Pipecat Cloud when its managed deployment boundary fits. Add Speko only if routed model services are useful inside that loop.
Official sources
[Pipecat documentation](https://docs.pipecat.ai/) [Pipecat Cloud documentation](https://docs.pipecat.ai/pipecat-cloud/introduction) [Pipecat repository](https://github.com/pipecat-ai/pipecat)
Last checked 2026-07-31
## A practical evaluation order
1. Decide who owns telephony and media transport.
2. Decide whether the conversation loop lives in a hosted product or in your runtime.
3. Decide whether model choice is fixed, application-managed or delegated to a router.
4. Compare latency, quality, cost, failure behavior and observability on the same calls.
Implementation paths
- [Voice agent infrastructure map](https://speko.ai/voice-agent-infrastructure/)
- [Latency measurement framework](https://speko.ai/voice-agent-latency/)
- [Pipecat with Speko](https://speko.ai/docs/pipecat/)
- [LiveKit with Speko](https://speko.ai/docs/livekit/)
- [LiveKit Agents documentation](https://docs.livekit.io/agents/)