Agentic Index
Telnyx vs Vapi (2026)
Both host voice agents that a team configures through an API or a dashboard, with the model, speech to text and voice chosen per agent, and they differ on what sits underneath. That verdict is the Agentic Index coverage score, graded from each vendor's own published materials.
Vapi runs the conversation loop on top of other carriers, answering on Vapi, Twilio, Telnyx or SIP numbers, and bills a $0.05 a minute hosting fee with each provider charged at cost, about $82 to $129 per 1,000 minutes at its defaults. Squads split a call across assistants, and Evals and Simulations test them. Telnyx owns the network and the GPUs. Its voice engine costs $0.05 a minute including speech to text, text to speech and knowledge retrieval, with models such as Kimi hosted on Telnyx and telephony on its own carrier, for about $0.06 a minute all in by its estimate. Conversation workflows, AI tests and percentage rollouts cover the same ground as Vapi's tools. Choose Vapi to mix providers and carriers freely, and Telnyx when one supplier should carry the number, the call and the model.
This comparison is published by Agentic Index, an independent agentic AI vendor research platform. Telnyx and Vapi are each graded against the same 14 capability Agentic Index taxonomy, from the vendor's own public materials under the Agentic Index verification standard, alongside 955 researched vendors. No vendor pays for placement and no vendor has reviewed this page. How this evidence is graded
Choose Telnyx if
- The phone number, the call, the speech models and the language model should come from one supplier on its own network.
- One per minute price should cover orchestration, speech to text, text to speech and knowledge retrieval.
- A new version should take a percentage of traffic or selected callers first, with rollback in one step.
- A caller's earlier conversations should be loaded into context at the start of each call.
- Business accounts should sign in through SAML with Okta, Azure Active Directory, Google or OneLogin.
Choose Vapi if
- Your numbers already sit with Twilio or another carrier and should stay there.
- Each provider should bill at cost with no markup, on your own keys.
- Simulations should run full conversations against AI testers with mocked tools before release.
- Outbound campaigns should dial contact lists on a schedule within a dispatch window.
- Monitors should flag quality drops on live calls and open issues.
| Feature | T Telnyx |
V Vapi |
|---|---|---|
| Action & orchestration | ||
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Integrations & Tool Calling Ability to connect agents to real systems through native integrations, OAuth-authenticated actions, custom tools, APIs, webhooks, or MCP-compatible tools. |
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TelnyxIntegrations & Tool Calling Assistants call outside systems with webhook tools, which can run asynchronously with filler messages while the request completes, attach MCP servers for whole tool catalogs, and connect enterprise integrations for Salesforce, Zendesk and Jira. Call control tools transfer the caller, hand off with SIP Refer, send DTMF tones to another phone system and hang up, client side tools run actions in the web widget, and keys for outside providers are kept as write only integration secrets. Tools live in a shared library that several assistants and workflow nodes can reuse. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/no-code-voice-assistant.mdread 2026-10-11 |
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VapiIntegrations & Tool Calling Function tools call the customer's server logic, and API Request tools call any HTTPS API directly with credentials held by reference. MCP tools connect an assistant to external MCP servers at runtime. Built in tools transfer calls, end calls, send SMS and press DTMF keys, and prebuilt integrations include Google Calendar event creation, Make and n8n. Deepgram, OpenAI and other providers are model layers, not integrations. SourceVapi, docs.vapi.ai (Function tools, Integrations, Built-in tools)read 2026-09-27 |
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Workflow Orchestration Ability to sequence, branch, retry, route, and combine deterministic workflow nodes with autonomous agent steps. |
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TelnyxWorkflow Orchestration Conversation workflows store a directed graph on the assistant. Prompt nodes run the model with their own instructions and optional model and voice overrides, speak nodes play a fixed message, and tool nodes run one shared tool and advance. Edges move between nodes on a natural language condition the model judges, a deterministic comparison against variables, or a default, and a tool node's HTTP status code can steer the next edge. An edge can also hand the conversation to another assistant, so a triage assistant can route billing, technical and sales callers to specialists that share the conversation's context. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/workflows.mdread 2026-10-11 |
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VapiWorkflow Orchestration Squads split a call across specialized assistants that hand off to each other through handoff tools with declared destinations, resolved at runtime. Context passing, variable extraction and rejection rules are all configurable, and the squad examples route callers by verification and inquiry type. Vapi's older Workflows builder has been retired and its flows moved to Squads. SourceVapi, docs.vapi.ai (Introduction to Squads, Handoff tool, Workflows migration guide)read 2026-09-27 |
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Triggers & Channel Coverage How agents wake up and where they work: schedules, webhooks, message events, CRM events, inbox events, chat, email, voice, and collaboration tools. |
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TelnyxTriggers & Channel Coverage Calls reach an assistant on an assigned Telnyx number or over SIP, outbound calls start from the portal, the API or the TeXML ai_calls endpoint, and an embeddable widget carries voice and chat on a web page. SMS conversations run through the assistant SMS chat API, with MMS during a call when messaging is on. At the start of each conversation a dynamic variables webhook can load caller details and memory settings, and custom SIP headers or the outbound request can pass variables in. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/no-code-voice-assistant.mdread 2026-10-11 |
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VapiTriggers & Channel Coverage Outbound campaigns carry a schedulePlan with an earliest and latest dispatch time, so Vapi starts dialing a contact list on its own schedule, with pre dial webhooks. Assistant hooks run actions on call events. Agents also answer on Vapi, Twilio, Telnyx and SIP numbers, in web calls and over SMS chat. SourceVapi, docs.vapi.ai (Campaign scheduling and lifecycle, Assistant hooks, SIP introduction, SMS chat)read 2026-09-27 |
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| Knowledge & context | ||
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Knowledge Grounding & RAG Ability to ground agent behavior in company data through document ingestion, retrieval, external knowledge APIs, semantic search, or RAG layers. |
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TelnyxKnowledge Grounding & RAG Each assistant can use named knowledge bases built from uploaded files or a URL, kept with the account and attached in the assistant's configuration, so one knowledge base can serve several assistants. Retrieval during a call is part of the voice engine's orchestration and included in the per minute price, while the price estimator carries a separate agent knowledge base add on. Telnyx does not say how the content is chunked or indexed. Sourcetelnyx.com/pricing/conversational-airead 2026-10-11 |
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VapiKnowledge Grounding & RAG Knowledge bases are the customer's uploaded files, such as txt, pdf, docx, csv, md and more, added through the dashboard or the file API, kept in Vapi and attached to assistants. During a call the query tool searches them by file ID, with Google Gemini models doing the retrieval, and new knowledge is added by uploading a file instead of retraining. A custom knowledge base can swap in the customer's own retrieval server. SourceVapi, docs.vapi.ai (Knowledge bases, Query tool)read 2026-09-27 |
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Memory & State Persistence Ability to persist context across a run, conversation, workflow, user, team, or longer-term memory layer. |
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TelnyxMemory & State Persistence Memory brings earlier conversations into a new one. The dynamic variables webhook returns a query in the same form as the List Conversations endpoint, typically the caller's phone number, a time window or custom metadata, plus the IDs of insights to include, and the assistant starts with those conversations and insight results in context, across voice and messaging. The webhook has one second to answer before the call carries on without memory. What comes back is stored conversation history picked by the customer's query. There is no separate memory store, and Telnyx sets out no retention period or way to delete one person's history. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/memoryread 2026-10-11 |
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VapiMemory & State Persistence For chat and SMS, a sessionId groups chats under one persisted conversation that expires 24 hours after creation by default (expirationSeconds). Sessions can be read in session logs and deleted through the API, and within a call, squads carry context across handoffs. Nothing the agent learns about a caller is kept beyond the session. SourceVapi, docs.vapi.ai (Session management, Session logs)read 2026-09-27 |
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| Control & trust | ||
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Human Oversight & Guardrails Approval steps, consent checkpoints, escalation rules, structured guardrails, policy constraints, and pause/resume controls. |
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TelnyxHuman Oversight & Guardrails Transfer and SIP Refer tools pass a caller to a person or another phone system, with voicemail detection on transfer, and handoff tools move a conversation between assistants. Releases stay under the team's control. A new version is saved with notes, traffic rules send selected callers or a percentage to it, and rollback returns all traffic to the main version at once. No step lets a person approve a tool call or a reply before the assistant acts. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/version-testing-traffic-distribution.mdread 2026-10-11 |
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VapiHuman Oversight & Guardrails A tool rejection plan attaches conditions to any tool and blocks the call when the recent conversation state matches them, and handoff rejection rules block unwanted transfers between assistants. Transfer tools hand a caller to a person by blind or warm transfer. There is no approval step that holds an action until a person signs off, so escalation hands over the whole conversation. SourceVapi, docs.vapi.ai (Tool rejection plan, Transfer Call tool)read 2026-09-27 |
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Security, Identity & Governance RBAC, SSO, auditability, encryption, least-privilege tool access, compliance posture, and data handling policy. |
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TelnyxSecurity, Identity & Governance Business accounts sign in to the Mission Control Portal through SAML single sign on with Okta, Azure Active Directory, Google, OneLogin, Auth0 or LastPass. Telnyx holds ISO 27001:2022 and ISO 27701, a SOC 2 Type II report under NDA covering voice, messaging, video and wireless, and HIPAA coverage for voice, messaging, fax and AI inference with a BAA available, plus PCI DSS for its own billing. The SOC 2 scope does not name AI assistants, and Telnyx also claims a SOC 2 Type III, a report type the AICPA does not issue. Sourcetelnyx.com/ai/compliance.mdread 2026-10-11 |
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VapiSecurity, Identity & Governance Vapi supports SSO through any SAML 2.0 or OIDC identity provider on the Enterprise and Premier plans, and RBAC with Admin, Editor and Viewer roles assigned per member. SCIM is not supported. Vapi's SafeBase trust center announces a completed SOC 2 Type II examination, with the report under NDA, and a public SOC 3, and lists HIPAA, PCI DSS v4.0.1, GDPR and CCPA. HIPAA mode and zero data retention are organization settings. SourceVapi, docs.vapi.ai (Single Sign-On) and security.vapi.airead 2026-09-27 |
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Observability & Auditability Traces, logs, execution histories, metrics, audit events, and debugging detail for production agent behavior. |
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TelnyxObservability & Auditability Every conversation is stored and listable through the conversations API, transcripts show which workflow node produced each assistant message, and the last tool call's HTTP status is kept as a variable. Insight groups run structured and unstructured analysis on each conversation and can post results to a webhook, with Telnyx managed insights alongside custom ones. Version notes record what changed in each release, and Telnyx does not mention an audit trail of who changed an assistant's configuration. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/workflows.mdread 2026-10-11 |
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VapiObservability & Auditability Call logs hold the transcript, messages, analysis, costs, latency, recordings and downloadable pipeline logs for each call, with chat, session, webhook and API request logs beside them. Monitors evaluate call data against thresholds and open issues. Raw data is kept for 14 to 180 days depending on the package. SourceVapi, docs.vapi.ai (Call logs, Logs overview, Monitoring quickstart) and vapi.ai/pricingread 2026-09-27 |
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Deployment & Data Residency Deployment modes and options, including SaaS, dedicated cloud, VPC, on-prem, hybrid, local runtime, and self-hosting. |
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TelnyxDeployment & Data Residency Voice AI agents run in the United States, the primary data center, or in the European Union with EU data residency, where data does not leave the EU. AI inference is also offered in Asia Pacific with regional processing, though voice agents are not offered there, and Canada has neither. The assistant's language model can also point at the customer's own OpenAI compatible endpoint, such as one on AWS Bedrock, Azure OpenAI or a self run vLLM server, which keeps inference inside an environment the customer controls. Sourcetelnyx.com/ai/compliance.mdread 2026-10-11 |
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VapiDeployment & Data Residency Each organization belongs to the United States or the European Union region, with its own dashboard, API and SIP hosts, such as api.eu.vapi.ai and sip.eu.vapi.ai in the EU. Every resource stays in its region, and each region is an isolated environment. The service is hosted only, with no self hosted or customer tenant option. SourceVapi, docs.vapi.ai (EU region and data residency)read 2026-09-27 |
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| Solution readiness | ||
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Prebuilt Agents, Templates & Packs Ready-made workflows, packaged employees, templates, blueprints, industry solutions, and role-specific agents that reduce time-to-value. |
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TelnyxPrebuilt Agents, Templates & Packs New assistants start from a template in the portal, with a blank template as the usual starting point, and Telnyx managed insights come ready to attach to any assistant. A shared tools library lets one set of tools serve many assistants. Telnyx offers no catalog of finished agents for support, sales or scheduling. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/no-code-voice-assistant.mdread 2026-10-11 |
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VapiPrebuilt Agents, Templates & Packs Cloneable example builds cover appointment scheduling, medical triage and scheduling, ecommerce order management, property management routing, lead qualification and multilingual support. Each does a different job, but the customer builds each one step by step instead of adopting a packaged agent. Model Intelligence presets are settings. SourceVapi, docs.vapi.ai (Guides)read 2026-09-27 |
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| Platform extensibility | ||
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Model Flexibility & Routing Ability to work across multiple foundation models, route tasks to different models, or let buyers bring their own providers and keys. |
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TelnyxModel Flexibility & Routing The customer picks the model for each assistant on the Agent tab. Options include models hosted on Telnyx GPUs, with Kimi as the default, managed third party models from providers such as OpenAI, Gemini and Groq, with OpenAI models on the customer's own key, and any public OpenAI compatible endpoint such as AWS Bedrock, Azure OpenAI, Baseten, vLLM or SGLang. Prompt nodes in a workflow can override the model step by step, and speech to text and text to speech providers are chosen separately. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/custom-llm.mdread 2026-10-11 |
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VapiModel Flexibility & Routing Each assistant's transcriber, model and voice can be swapped for any supported provider. Customers can use their own provider keys, Azure OpenAI and Bedrock credentials, or their own server acting as the LLM. Transcriber and voice fallback plans switch providers automatically on failure. SourceVapi, docs.vapi.ai (Core Models, Provider Keys, Custom LLM, fallback configuration)read 2026-09-27 |
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APIs, SDKs & MCP Extensibility Composability layer: stable APIs, SDKs, MCP tool consumption/serving, custom tools, and integration into internal systems. |
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TelnyxAPIs, SDKs & MCP Extensibility The API covers assistants end to end, including creating and updating assistants, assistant tests, canary deploys, MCP server records, SMS chat and a chat endpoint in beta, and the TeXML ai_calls endpoint starts outbound calls. Coding assistants can read the whole reference through llms.txt indexes, and the conversations API hands stored conversations to other systems. Sourcedevelopers.telnyx.com/development/llms/ai-assistants-llms-txtread 2026-10-11 |
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VapiAPIs, SDKs & MCP Extensibility The API covers assistants, squads, calls, chats, campaigns, sessions and phone numbers, with server SDKs, a Web SDK and a CLI beside it. The Vapi MCP Server at mcp.vapi.ai, authenticated by bearer token, manages assistants, phone numbers and calls from any MCP client. SourceVapi, docs.vapi.ai (API reference, Vapi MCP Server)read 2026-09-27 |
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Testing, Debugging & Optimization Testing, debugging, scoring, retries, fallbacks, quality gates, and optimization loops for improving agent workflows before and after deployment. |
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TelnyxTesting, Debugging & Optimization AI tests give each check a name, a target assistant and success criteria, such as what the greeting must say, and a test run shows progress live and reports whether the assistant met every criterion, with the conversation to review. A new version can be saved with notes and sent a share of traffic by ordered rules on the caller's number, all to one version or split by percentage, with the remainder staying on the main version, and rollback clears every rule at once. Coval can generate test conversations from seed cases. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/version-testing-traffic-distribution.mdread 2026-10-11 |
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VapiTesting, Debugging & Optimization Evals test assistants and squads with mock conversations, using exact, regex or AI judged checks and tool call checks, and return pass or fail. Simulations run full conversations against AI testers with success criteria and tool mocks, and the testing guides set a release and regression cadence. SourceVapi, docs.vapi.ai (Evals quickstart, Simulations overview, Run and maintain tests)read 2026-09-27 |
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| Specialist automation | ||
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Browser & Computer Use Browser, desktop, or remote/local computer control for workflows that cannot be handled through stable APIs alone. |
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TelnyxBrowser & Computer Use Assistants act through webhooks, MCP servers, integrations and call control tools, and send keypad tones to other phone systems. No hosted browser, remote desktop or screen control is offered. Sourcedevelopers.telnyx.com/docs/inference/ai-assistants/tools-library.mdread 2026-10-11 |
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VapiBrowser & Computer Use Browser, desktop and computer control are not described. IVR navigation presses DTMF keys to walk a phone menu on a telephone keypad, not a screen. Web SDK client side tools trigger side effects in the customer's own web app, which is the product running in a browser. SourceVapi, docs.vapi.ai (llms.txt, IVR Navigation, Client-side tools)read 2026-09-27 |
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Pricing snapshot
Sourced from the Index pricing dataset · open each vendor's profile for full detail.
| Pricing | T Telnyx |
V Vapi |
|---|---|---|
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Entry price Lowest public entry point |
$0.05 a minute for the voice engine, including speech to text, text to speech and knowledge retrieval, with LLM tokens and telephony extra | $0.05 a minute hosting fee plus provider costs, usage based. Success packages from $29 a month. |
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Pricing confidence How public the numbers are |
Public, exact | Public, exact |
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Billing Primary billing axis |
Per minute of voice engine time, rounded up to whole minutes per call, plus LLM tokens, per minute telephony and monthly number rental | Usage, billed per call minute and prepaid. |
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Variable cost Workload / overage exposure |
High variable cost | High variable cost |
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Free tier / trial Try before you buy |
No free tier
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Free tierTrial
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Buying motion Self-serve vs sales call |
Mixed | Mixed |
Vapi answers calls on Telnyx numbers among others, so the two are sometimes used together. Vapi's HIPAA mode is a $2,000 a month add on. Telnyx's SOC 2 report does not name AI assistants in its scope, though its HIPAA coverage includes AI inference.
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