Vapi vs telli
telli wins · 14–23 (24 drawn)
Agent building — building agents — abstractions, tool wiring, control flowAgent building
Building agents — abstractions, tool wiring, control flow
Agent ops
ai-native userMy coding agent can provision a complete voice agent end to end — create the agent, attach a number, and place a call — through the API, CLI, or MCP without touching the dashboard
weight 3 · round to VapiVapi documents API/SDK-based assistant creation, phone number attachment, and call placement (vapi-docs-1, vapi-docs-18, vapi-docs-19), a CLI for managing assistants, phone numbers, and calls entirely from the terminal (vapi-docs-2, vapi-docs-31, vapi-probe-rt-1 confirming keyless install/version), and an official MCP server exposing these same operations to any MCP-compatible agent, verified live and auth-gated in a runtime probe (vapi-docs-33, vapi-probe-rt-2). Together these three surfaces (API, CLI, MCP) cover the full agent-provision-number-call workflow without dashboard use. missing for 10: no single end-to-end hands-on trace showing one agent chaining create→attach→call purely via CLI/MCP/API in one session, and no independent (non-vendor) confirmation of the full workflow succeeding.
- [claimed-docs] “const assistant = await vapi.assistant”
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “Create a voice assistant, connect it to a phone number, and make your first calls.”
- [claimed-docs] “In under 5 minutes, you'll create a voice assistant and start talking to it over the phone.”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
- [probe] “official CLI documented at https://docs.vapi.ai/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
telli's REST API documents endpoints for scheduling calls and importing/attaching phone numbers (telli-docs-17, telli-docs-19), and the MCP server lets AI tools talk to Charlie, who can 'build and refine agents' (telli-docs-11, telli-docs-22), suggesting agent creation is possible without the dashboard. However, there is no explicit API/CLI 'create agent' endpoint documented, no CLI tool is mentioned at all, and the MCP-driven agent creation is only described as an assistant chat capability rather than a deterministic API call — so a full end-to-end create→attach-number→place-call pipeline via one consistent interface is not clearly evidenced. Missing for 10: a documented create-agent API/CLI endpoint, confirmation MCP/Charlie can fully provision agents without any dashboard step, and an example combining all three steps in one flow.
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
ai-native userThe platform's own AI helps me author agents — generating or improving prompts, flows, and test cases from a description
weight 1 · round to telliVapinone0/10Evidence shows Vapi provides CLI, MCP server, tool/webhook infrastructure, and testing frameworks (Evals, Voice Test Suites), plus a Customer Support template, but nothing indicates the platform itself uses AI to generate or improve prompts, conversation flows, or test cases from a natural-language description — testing tools require manually defined mock conversations/scripts rather than AI-authored ones.
- [claimed-docs] “Voice Test Suites enable you to test your AI voice agents through simulated phone conversations.”
- [claimed-docs] “Evals is Vapi's AI agent testing framework that enables you to systematically test assistants and squads using mock conversations with autom…”
- [claimed-docs] “Our AI tester calls your voice agent and follows a script that simulates real customer behavior.”
- [claimed-docs] “you'll create mock conversations, define expected behaviors, and validate your agents work correctly before production”
- [claimed-docs] “Select the down arrow next to Create Assistant, then choose Customer Support.”
Charlie, telli's built-in AI assistant, is documented as helping to 'build and refine agents, automate workflows, and analyze your calls,' which supports the core idea of AI-assisted agent authoring, and the MCP server lets external AI tools interact with Charlie too. However there's no concrete evidence of generating test cases from a description, or detailed examples of prompt/flow generation output. missing for 10: documented examples of Charlie generating/improving prompts or flows from a natural-language description, evidence of AI-generated test case creation, and independent/hands-on confirmation of these capabilities in practice.
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
Build
developerBuild a working phone voice agent — prompt, voice, and phone number — and take my first live call within an hour
weight 3 · round to VapiDocs explicitly walk through creating a voice assistant, connecting a phone number, and making a first call in under 5 minutes (vapi-docs-18, vapi-docs-19), with voice selection via the Voice Library (vapi-docs-8, vapi-docs-24) and dashboard-driven assistant creation with templates (vapi-docs-16); community evidence corroborates a working live-call demo (vapi-comm-1). Missing for 10: independent third-party benchmarking of the full 'within an hour' timing claim beyond vendor docs and a single anecdotal community comment.
- [claimed-docs] “Create a voice assistant, connect it to a phone number, and make your first calls.”
- [claimed-docs] “In under 5 minutes, you'll create a voice assistant and start talking to it over the phone.”
- [claimed-docs] “Select the down arrow next to Create Assistant, then choose Customer Support.”
- [claimed-docs] “The Voice Library in the Vapi Dashboard lists every voice available to your organization. Browse and preview voices there”
- [claimed-docs] “Browse and preview voices there, then copy a voice's ID to use on an assistant.”
- [community] “Called the demo number, sounds smooth! Good luck.”
telli provides agent builder, test call feature, voice cloning, and phone number setup (forwarding or SIP trunk import) which together support building and testing a voice agent with prompt, voice, and number, but there's no explicit walkthrough or evidence confirming a full end-to-end setup can be completed within an hour or that phone number provisioning is instant/self-serve for new numbers. missing for 10: a documented quick-start/time-to-first-call benchmark, evidence of instant/native number provisioning (vs SIP/forwarding setup), and independent/hands-on confirmation of the full flow's speed.
- [claimed-docs] “In the agent builder, click Test call to open the dialog. Pick the agent version (your draft with unsaved changes or any saved revision)...”
- [claimed-docs] “Use the side-by-side view to listen to the recording while following along in the transcript.”
- [claimed-docs] “Voice cloning lets you give your agent a custom voice (your own, a colleague's, or a professional voice actor's), so the agent sounds exactl…”
- [claimed-docs] “Keep your public business number and forward incoming calls to a telli number. You configure the forwarding with your phone provider or PBX.”
- [claimed-docs] “Connect an existing number and phone system for incoming and outgoing calls. You need SIP trunk access from your provider.”
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
developerRun conversations in multiple languages, including detecting and switching language mid-call
weight 2 · round drawnVapinone0/10The evidence pack covers CLI, MCP server, tools, voices, compliance, and testing, but contains no mention of multi-language support, language detection, or mid-call language switching capabilities. Absence of evidence for this applicable axis (multilingual voice agents are a fair capability to expect from a voice AI platform) means it must be judged 'none'. missing for 10: any mention of multi-language conversation support, language auto-detection, or mid-call language switching features.
founderDesign multi-step conversation flows in a visual builder with branching, states, and handoffs without writing code
weight 2 · round to telliVapinone0/10Evidence covers Vapi's assistant configuration, tools, CLI, MCP server, voices, and testing, but there is no mention of a visual flow builder with branching, states, or handoffs — Vapi appears configuration/code-driven (assistant config, function tools, webhooks) rather than a no-code visual conversation designer.
telli has an 'agent builder' with test-call and versioning, and workflow triggers (scheduled, SMS/WhatsApp) suggesting some no-code workflow configuration, plus tool-calls like transfer to another agent implying handoffs. But there's no evidence of a visual flow builder with branching/state diagrams — evidence only shows agent settings, tools, and triggers, not a drag-and-drop conversation flow canvas. missing for 10: explicit visual builder UI with branching/state nodes, evidence of designing multi-step flows with conditional paths, and documentation of handoff logic beyond simple 'transfer tool'.
- [claimed-docs] “In the agent builder, click Test call to open the dialog. Pick the agent version (your draft with unsaved changes or any saved revision)...”
- [claimed-docs] “Transfer tools | Move the call to another agent or number.”
- [claimed-docs] “Choose SMS and WhatsApp workflow recipients from contact properties, collected values, or a fixed number”
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
Personalization
developerInject dynamic variables and per-caller context at call time so each conversation is personalized
weight 2 · round drawnVapinone0/10The evidence pack covers assistant creation, tools/webhooks, CLI, MCP server, voices, and testing, but contains no documentation of variable injection, assistantOverrides, or per-caller context personalization at call time. Missing for 10: docs on dynamic variable substitution (e.g., {{variableName}} templating), call-time overrides/metadata injection, and any example showing per-caller personalization.
tellinone0/10The evidence describes contact properties and collected values being used to select SMS/WhatsApp recipients (telli-docs-5) and APIs to manage contacts and schedule calls (telli-docs-12, telli-docs-17), but nowhere does it document injecting dynamic variables or per-caller context into an agent's voice call script/persona at call time. Missing for 10: explicit documentation of variable placeholders in agent prompts, a mechanism for passing per-call custom data via the schedule-call API, and any example of personalized call content driven by caller-specific fields.
- [claimed-docs] “Choose SMS and WhatsApp workflow recipients from contact properties, collected values, or a fixed number”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
developerGround the agent on my documents with a built-in knowledge base or RAG so it answers from my content
weight 2 · round drawnVapinone0/10Vapi is a voice-agent platform focused on assistants, phone numbers, custom webhook tools, and telephony/testing; the evidence pack shows no built-in knowledge base or RAG feature for grounding assistants on uploaded documents. Custom tools/webhooks could be used to build a workaround, but no document ingestion or retrieval capability is documented.
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “This guide shows you how to create custom tools, including Function Tools, for your Vapi assistants.”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
Agenticness — how well agents can access and operate the productAgenticness
How well agents can access and operate the product
Agent access
ai-native userPoint an agent at llms.txt or agent-oriented docs
weight 2 · round to telliVapi confirms an llms.txt file exists and is served at docs.vapi.ai/llms.txt (HTTP 200), explicitly instructing agents on how to fetch clean Markdown per page, which directly satisfies the story. missing for 10: no independent/community corroboration of agents actually consuming llms.txt in practice, only first-party probe evidence.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.vapi.ai/llms.txt # Vapi ## Instructions for AI Agents - For clean Markdown of any page, append `.…”
telli hosts a live llms.txt file (confirmed via probe, HTTP 200) plus machine-readable OpenAPI spec explicitly intended for coding agents, and docs also mention agent-oriented context for downloading API specs. missing for 10: no independent/third-party confirmation of an agent successfully consuming llms.txt in practice.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.telli.com/llms.txt # telli Documentation > telli is the AI voice platform for agents that sell, su…”
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
ai-native userRun the product headlessly / in CI for automation
weight 2 · round drawnVapi ships an official CLI (vapi-docs-2/31/32, confirmed working keylessly in vapi-probe-rt-1) that can manage assistants, calls, and forward webhooks, which supports scripted/CI-style usage, and SDKs/REST APIs imply headless programmatic calls. However there is no explicit CI/automation documentation, no examples of running in a pipeline, and the MCP server requires bearer-key auth (vapi-probe-rt-2) which is unaddressed for CI contexts. missing for 10: explicit CI/automation examples or docs, non-interactive auth/service-account flow for CI, evidence of headless voice-testing/evals running in a pipeline.
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
- [claimed-docs] “The CLI auto-detects your tech stack and sets up everything you need.”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [claimed-docs] “Evals is Vapi's AI agent testing framework that enables you to systematically test assistants and squads using mock conversations with autom…”
- [claimed-docs] “you'll create mock conversations, define expected behaviors, and validate your agents work correctly before production”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
telli exposes a full REST API (with OpenAPI spec) to programmatically schedule calls, manage contacts, and trigger workflows, plus webhooks for event-driven automation and scheduled/recurring workflow triggers — all of which support headless, non-UI automation suitable for CI-like pipelines. However there is no explicit CI/CD example, CLI tool, or documented automated pipeline integration beyond the API/webhook primitives. Missing for 10: dedicated CI/CD documentation or examples, a CLI for scripted invocation, and independent confirmation of headless use in production pipelines.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
ai-native userPlug MCP servers into this product so it can use their tools
weight 3 · round drawnVapinone0/10The evidence shows Vapi exposes its own APIs as an MCP server (so external MCP clients like Claude Desktop can control Vapi), but this is the opposite direction from the story — there's no evidence that Vapi assistants can consume/plug-in external MCP servers to use their tools within a conversation. Vapi's tool docs describe webhook-based custom tools and OpenAI-style function calling only, with no mention of MCP-server ingestion.
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
tellinone0/10Telli's documented MCP support only runs in the opposite direction — it exposes an MCP server so external AI tools (Claude, ChatGPT, Codex) can talk to its Charlie assistant (telli-docs-22, telli-probe-3), not a mechanism for telli's own voice agents to consume external MCP servers' tools. Custom Tools (telli-docs-14, telli-docs-20) let agents call external APIs but are described as custom integrations, not MCP-based tool ingestion.
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
- [claimed-docs] “Custom Tools: Extend telli's capabilities with custom integrations and workflows.”
- [claimed-docs] “Custom tools allow your AI agents to access external information by connecting to your APIs.”
ai-native userConnect an agent via an official MCP server
weight 3 · round to VapiVapi ships an official hosted MCP server (mcp.vapi.ai) exposing its assistant/phone/call APIs as MCP tools for any MCP-compatible agent (Claude Desktop, agent frameworks), documented in first-party docs and confirmed live via a runtime probe (401 bearer-key gate exactly as documented). Missing for 10: independent/community hands-on testimonials specifically about using the MCP server (community evidence only covers general demo/founder trivia, not MCP usage).
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
telli documents an official MCP server that lets external AI tools (Claude, ChatGPT, Codex) connect over the Model Context Protocol to interact with Charlie, telli's assistant, confirmed both in docs and via a live probe of the integrations/mcp page. Missing for 10: no independent/hands-on corroboration beyond first-party docs and the probe, and no detail on server setup/auth specifics.
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
ai-native userUse an official CLI
weight 2 · round to VapiVapi ships a documented official CLI for managing assistants, phone numbers, and calls from the terminal, with webhook forwarding, org/environment switching, and tech-stack auto-detection, and this was independently verified in a runtime probe (successful install and `--version` output). missing for 10: no independent third-party review or community discussion of the CLI's day-to-day usage beyond the vendor docs and single install probe.
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “vapi listen --forward-to localhost:3000/webhook”
- [claimed-docs] “Switch between organizations and environments seamlessly”
- [claimed-docs] “Forward webhooks to your local server for debugging”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
- [claimed-docs] “The CLI auto-detects your tech stack and sets up everything you need.”
- [probe] “official CLI documented at https://docs.vapi.ai/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
ai-native userDrive the product through a documented public API
weight 3 · round drawnVapi ships a documented public API/SDK (assistant management, calls, tools), a CLI for terminal-driven workflows, and a hosted MCP server exposing the API as tools, all confirmed by runtime probes (CLI installs and runs, MCP endpoint live and auth-gated as documented). This directly satisfies programmatic/AI-native control via a documented public interface. Missing for 10: no independent third-party developer report deeply exercising the API beyond docs/probes.
- [claimed-docs] “const assistant = await vapi.assistant”
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.vapi.ai/llms.txt # Vapi ## Instructions for AI Agents - For clean Markdown of any page, append `.…”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
- [probe] “official CLI documented at https://docs.vapi.ai/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
telli documents a REST API with endpoints (schedule-call, import-phone-number), API key/bearer auth, webhooks, and a downloadable OpenAPI spec (confirmed live at openapi.json), plus an MCP server for AI tool access — enabling full programmatic/agentic control. missing for 10: independent third-party validation of API robustness beyond vendor docs.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
ai-native userIssue scoped/least-privilege API credentials for an agent
weight 2 · round to VapiVapi's enterprise docs mention Role Based Access Control (RBAC) and SSO, implying some access-scoping capability at the org level, and its MCP server/API require bearer API keys — but there is no documented mechanism for issuing per-agent, least-privilege scoped API keys or tokens tailored to a specific agent's permissions. missing for 10: explicit scoped API key creation/management UI or API, documentation of key-level permission granularity, and independent confirmation that RBAC restricts agent credentials rather than just human dashboard users.
- [claimed-docs] “Single Sign On (SSO) supported for Okta, Azure AD, SAML, and OIDC * Role Based Access Control (RBAC)”
- [claimed-docs] “Single Sign On (SSO) supported for Okta, Azure AD, SAML, and OIDC”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
tellinone0/10telli documents a single API key (bearer token) generated in Settings > Developer, but there's no evidence of scoped permissions, role-based keys, or least-privilege credential issuance for agents specifically.
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
ai-native userBuild against official SDKs
weight 2 · round to VapiVapi documents an official JS/TS SDK usage pattern, official CLI (probe-confirmed installed and runnable), and official MCP server (probe-confirmed live and auth-gated), all clearly aimed at AI-native/agentic developer workflows including IDE assistant integration (Cursor/Windsurf/VSCode). missing for 10: independent third-party corroboration of SDK code quality and coverage across multiple languages beyond the docs snippets.
- [claimed-docs] “const assistant = await vapi.assistant”
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Your IDE's AI assistant (Cursor, Windsurf, VSCode) gains complete, accurate knowledge of Vapi's APIs and best practices. No more hallucinate…”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
- [probe] “official CLI documented at https://docs.vapi.ai/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
telli provides a REST API with an OpenAPI spec that can be used to generate client libraries, plus webhooks, custom tools, and an MCP server for agent integration, but there is no evidence of telli-maintained official SDKs in specific languages (e.g., Python/JS packages published by telli) — only self-generated clients from the OpenAPI spec. missing for 10: dedicated first-party SDK packages/repos, language-specific SDK documentation, versioning/release notes for such SDKs.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
ai-native userSubscribe to events via webhooks
weight 2 · round to telliVapi supports webhook-based events via Server URL (tool-calls messages), custom webhook tools, and CLI webhook forwarding for local debugging, giving AI-native users a documented event subscription mechanism. missing for 10: independent/hands-on confirmation of webhook delivery reliability, a full event-type catalog/schema, and signature/verification documentation.
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “When tools are triggered, your Server URL receives a `tool-calls` message”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [claimed-docs] “Forward webhooks to your local server for debugging”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
telli documents a webhooks system that pushes real-time POST notifications about call events, status changes, and outcomes, explicitly described as event-driven subscription for external systems (telli-docs-13, telli-docs-21). Missing for 10: no evidence of configurable event-type filtering/subscription granularity or independent third-party confirmation of reliability.
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
Agentic features
ai-native userGet AI-generated insights and suggestions from my data inside the product
weight 2 · round to telliVapinone0/10Evidence covers building/testing assistants (Evals, Voice Test Suites), CLI/MCP management tools, and tool-calling, but nothing describes the product itself surfacing AI-generated insights or suggestions derived from a user's own call/usage data (e.g., analytics dashboards with AI-generated recommendations).
telli ships a built-in AI assistant (Charlie) that can 'analyze your calls' and help build/refine agents, plus dashboards for reach rate, call duration, success rate, and per-call transcript/outcome analysis, which together provide AI-driven insight into product data. However, the docs don't detail proactive, autonomous 'suggestions' surfaced to the user (e.g., recommended actions, anomaly detection) beyond on-demand analysis via Charlie or manual dashboard review. Missing for 10: concrete examples of Charlie proactively surfacing insights/recommendations, independent user corroboration of insight quality.
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
- [claimed-docs] “Analyze individual calls, transcripts, and call outcome fields.”
- [claimed-docs] “Submit feedback on calls to continuously improve your agent.”
ai-native userSet up automations that run autonomously in the background
weight 2 · round to telliVapi assistants operate autonomously once a call starts—handling conversation flow, invoking custom tools via webhooks, and triggering server-side automations without further human input (vapi-docs-6, vapi-docs-17, vapi-docs-23, vapi-docs-34). However, this autonomy is scoped to an active call session; there is no evidence of scheduled/cron-style background jobs or agent loops that run independently of a triggered call or user interaction. Missing for 10: evidence of scheduled/background triggers outside live calls, persistent autonomous task queues, or proactive (non-call-triggered) automation runs.
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “When tools are triggered, your Server URL receives a `tool-calls` message”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
- [claimed-docs] “This guide shows you how to create custom tools, including Function Tools, for your Vapi assistants.”
telli supports Scheduled triggers so workflows run automatically without a call event, plus retry/dialing-window configuration, webhooks, and an AI assistant (Charlie) to build/automate workflows — together enabling background autonomous automations. Missing for 10: independent/hands-on verification of scheduled automations running reliably in production, and more detail on monitoring/error-handling for autonomous runs beyond docs claims.
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
- [claimed-docs] “Configure dialing windows, calling strategies, and retry behavior.”
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
ai-native userDelegate tasks to a built-in AI assistant inside the product
weight 3 · round to telliVapinone0/10Vapi's docs describe building and configuring voice AI assistants for end-users (phone/web calls, tools, testing) and even an MCP server/CLI for managing those assistants, but there is no evidence of a built-in AI assistant/copilot inside the Vapi product itself that the AI-native user can delegate platform tasks to (e.g., an in-dashboard copilot that configures assistants or writes tools for you). The CLI mentions external IDE assistants (Cursor/Windsurf) gaining API knowledge, but that's a third-party tool, not a built-in in-product assistant.
- [claimed-docs] “Your IDE's AI assistant (Cursor, Windsurf, VSCode) gains complete, accurate knowledge of Vapi's APIs and best practices. No more hallucinate…”
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
telli documents "Charlie," a built-in AI assistant that can build/refine agents, automate workflows, and analyze calls, and this assistant is also exposed via an MCP server for external AI tools to interact with. This directly matches delegating tasks to a built-in assistant within the product. Missing for 10: independent/hands-on verification of Charlie's task delegation in practice and more detail on the scope of tasks it can autonomously execute.
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
ai-native userOperate the product with natural-language commands
weight 2 · round to VapiVapi exposes an official MCP server that lets any MCP-compatible AI assistant (e.g. Claude Desktop) manage assistants, phone numbers, and calls via natural-language tool calls, and this endpoint is confirmed live and auth-gated in a runtime probe. It also ships a CLI and llms.txt docs optimized for AI agents to operate it. Missing for 10: no first-party evidence of a built-in chat/NL command console inside the Vapi product itself (beyond MCP/CLI proxies), and no independent hands-on report of an agent successfully performing multi-step tasks via MCP.
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Your IDE's AI assistant (Cursor, Windsurf, VSCode) gains complete, accurate knowledge of Vapi's APIs and best practices. No more hallucinate…”
- [probe] “official MCP server documented at https://docs.vapi.ai/sdk/mcp-server”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.vapi.ai/llms.txt # Vapi ## Instructions for AI Agents - For clean Markdown of any page, append `.…”
telli offers Charlie, a built-in AI assistant that can build/refine agents, automate workflows, and analyze calls via natural language, plus an MCP server letting external AI tools (Claude, ChatGPT, Codex) converse with Charlie — both point to natural-language operation. However, most of the product surface (workflows, scheduling, dialing windows, phone number setup) is described as configured through UI/API rather than conversational commands, and there's no independent/hands-on evidence of Charlie's NL command scope or reliability. missing for 10: hands-on evidence of Charlie executing complex natural-language commands, documentation detailing the breadth of actions controllable purely via NL, independent corroboration beyond vendor docs.
- [claimed-docs] “Charlie: Build and refine agents, automate workflows, and analyze your calls with telli's built-in AI assistant.”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
Api quality
ai-native userExplore an interactive API reference with runnable examples
weight 2 · round to telliVapinone0/10The evidence pack shows static markdown documentation, code snippets, a CLI, and an MCP server, but no interactive API reference or runnable/try-it-out examples are described anywhere in the docs pages cited.
telli publishes an OpenAPI spec (openapi.json) and API docs with downloadable schemas for generating client libraries or feeding coding agents, but there is no evidence of an interactive reference with runnable/'try it' examples in-browser. missing for 10: an interactive try-it console, live runnable code samples, or sandboxed request execution within the docs site.
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
ai-native userDownload a machine-readable API spec (OpenAPI or equivalent)
weight 2 · round to telliVapinone0/10The evidence pack covers Vapi's CLI, MCP server, docs, and SDKs, but no citation mentions an OpenAPI spec, API reference schema, or any machine-readable spec file available for download. This is a fair axis for an API-first product, but no supporting evidence exists in the pack.
telli provides a downloadable OpenAPI spec confirmed live at /openapi.json, and docs explicitly state it can be downloaded to generate client libraries, import into tools, or give coding agents machine-readable API context. Missing for 10: no independent third-party confirmation of spec completeness/versioning beyond first-party docs and probe.
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
ai-native userTest against a sandbox environment without touching production data
weight 1 · round to VapiVapi offers dedicated Voice Test Suites (AI tester simulating conversations) and an Evals framework explicitly for creating mock conversations to 'validate your agents work correctly before production,' plus CLI webhook forwarding to localhost for local development/debugging — all separate from live production calls. Missing for 10: explicit vendor use of the term 'sandbox environment' and independent/hands-on verification that test runs are fully isolated from production data.
- [claimed-docs] “Voice Test Suites enable you to test your AI voice agents through simulated phone conversations.”
- [claimed-docs] “Evals is Vapi's AI agent testing framework that enables you to systematically test assistants and squads using mock conversations with autom…”
- [claimed-docs] “Our AI tester calls your voice agent and follows a script that simulates real customer behavior.”
- [claimed-docs] “you'll create mock conversations, define expected behaviors, and validate your agents work correctly before production”
- [claimed-docs] “Forward webhooks to your local server for debugging”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
telli's agent builder includes a 'Test call' feature that lets users dial a draft or saved agent version and review the recording/transcript before going live, which functions as a lightweight test mode (telli-docs-28, telli-docs-29). However, there is no documentation of a dedicated sandbox environment, separate test dataset, or explicit guarantee that test calls don't write to production contacts/analytics. missing for 10: explicit sandbox/staging environment separate from production, confirmation that test calls don't affect production data/metrics, and any mention of test API keys or isolated test accounts.
- [claimed-docs] “In the agent builder, click Test call to open the dialog. Pick the agent version (your draft with unsaved changes or any saved revision)...”
- [claimed-docs] “Use the side-by-side view to listen to the recording while following along in the transcript.”
ai-native userRely on versioned APIs with a documented deprecation policy
weight 2 · round drawnVapinone0/10No evidence pack item mentions API versioning scheme, version numbers in endpoints, or any documented deprecation/sunset policy for Vapi's APIs; the docs cover features (CLI, MCP, tools, voices) but not API lifecycle governance.
tellinone0/10Evidence shows an OpenAPI spec and API key auth exist, but nothing in the pack mentions API versioning (e.g., v1/v2 paths, version headers) or any documented deprecation/sunset policy for endpoints. Missing for 10: explicit API version scheme, changelog of breaking changes, and a stated deprecation/sunset policy.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
Automation depth — how much of the product can run unattendedAutomation depth
How much of the product can run unattended
ai-native userPerform bulk operations across many items at once
weight 2 · round to telliVapinone0/10The evidence pack documents CLI/SDK/MCP management of individual assistants, phone numbers, and calls, but nowhere shows bulk/batch endpoints or commands (e.g., batch-create, bulk-update, mass-delete) for operating across many items at once.
Telli's platform is built around calling large contact lists (dialing windows, calling strategies, retry behavior, reach-rate metrics) and its REST API lets users 'programmatically manage contacts, schedule calls' at scale, implying bulk campaign operations. However, there is no explicit documentation of a bulk-upload/bulk-schedule endpoint or UI for acting on many items simultaneously — the schedule-call endpoint documented is single-call oriented. Missing for 10: explicit bulk-contact import/schedule endpoint, documented batch size limits, and independent evidence of large-scale bulk execution.
- [claimed-docs] “Configure dialing windows, calling strategies, and retry behavior.”
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.telli.com/llms.txt # telli Documentation > telli is the AI voice platform for agents that sell, su…”
ai-native userDefine rules that trigger actions automatically on events
weight 3 · round drawnVapi supports event-driven server-side tools/webhooks that fire on call events (tool-calls messages, server-url events) which act as a rule-trigger mechanism, but this is scoped to voice-call events only rather than a general-purpose automation/rules engine for arbitrary triggers. missing for 10: a documented general condition/trigger-action rules engine spanning non-call events, cross-system automation, or independent hands-on evidence of complex conditional automation chains.
- [claimed-docs] “When tools are triggered, your Server URL receives a `tool-calls` message”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
telli's workflows can be triggered by call events (implied default) and now by a recurring schedule, and webhooks notify external systems on call events, showing some event-driven automation. However there's no documented rule-definition interface (conditions, event-type selection, if/then logic) for arbitrary events beyond calls/schedule. Missing for 10: explicit rule/condition builder, broader event-type coverage beyond calls, and evidence of user-defined trigger logic rather than fixed schedule/call triggers.
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
ai-native userSchedule recurring jobs or workflows
weight 2 · round to telliVapinone0/10No evidence in the pack shows Vapi supports scheduling recurring jobs, workflows, or automated recurring calls/tasks — the docs cover assistants, tools, CLI, MCP server, testing, and voice customization but nothing about cron-like scheduling or recurring automation triggers.
telli documents scheduled triggers that let workflows run recurringly on an interval/start time without a call event, directly matching the recurring-workflow story, and also supports scheduling individual calls via API. missing for 10: independent/hands-on corroboration of recurrence reliability and detail on editing/monitoring scheduled workflow runs.
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Optional flag to bypass dialing window restrictions for the scheduled call. When true, calls at the scheduled time regardless of dialing win…”
ai-native userVersion, review, and roll back my automations
weight 1 · round to telliVapinone0/10Vapi's docs cover assistant creation, tools, CLI, MCP server, and testing/evals, but there is no mention of versioning assistant configurations, review/approval workflows, or rollback to prior versions of automations. No evidence pack item addresses version history or rollback capability.
The only hint of versioning is in agent testing, where you can pick 'your draft with unsaved changes or any saved revision' (telli-docs-28), implying saved agent versions exist. However there is no documented review interface for comparing versions, no explicit rollback/restore action, and no versioning mentioned for broader automations/workflows (only agents). Missing for 10: explicit rollback UI/API, version diff/review tooling, and versioning coverage for workflows beyond agent test calls.
- [claimed-docs] “In the agent builder, click Test call to open the dialog. Pick the agent version (your draft with unsaved changes or any saved revision)...”
Compliance trust — stories about compliance trust in this arenaCompliance trust
Stories about compliance trust in this arena
Compliance
founderMeet call-recording consent and disclosure obligations with per-call recording controls and configurable data retention
weight 2 · round to telliVapinone0/10The evidence pack covers HIPAA toggle, SSO/RBAC, testing/evals, and CLI/MCP tooling, but contains no mention of call-recording enable/disable controls, consent disclosure features, or configurable data retention policies for call recordings — a fair and applicable axis for a voice-calling platform.
telli documents conditional recording based on caller consent and a configurable data-retention policy that auto-deletes contacts and call data after a defined age, directly addressing the founder's compliance need. However, evidence lacks detail on per-call granular controls (e.g., pause/resume, jurisdiction-specific disclosure scripts), audit logging of consent events, or independent verification that these features work as described. Missing for 10: per-call recording toggle/audit trail details, jurisdiction-specific disclosure templates, retention configuration granularity (e.g., per-data-type settings), and independent/hands-on confirmation of compliance behavior.
- [claimed-docs] “Data retention deletes contacts and call data automatically once they reach an age you define.”
- [claimed-docs] “In telli, you can easily make audio recording conditional on the caller's consent — so a call is only recorded once they agree.”
platform-engineerRun regulated workloads with HIPAA/BAA support, SOC 2, and data-residency options
weight 2 · round to VapiVapi documents HIPAA compliance toggle in the dashboard and enterprise SSO/RBAC, indicating some regulated-workload support, but evidence lacks explicit SOC 2 certification details, BAA execution process, or data-residency region options. missing for 10: SOC 2 report/certification evidence, explicit BAA process details, data-residency/region selection options, independent audit confirmation.
- [claimed-docs] “HIPAA compliance can be ensured by turning on HIPAA compliance in the Dashboard.”
- [claimed-docs] “Single Sign On (SSO) supported for Okta, Azure AD, SAML, and OIDC * Role Based Access Control (RBAC)”
- [claimed-docs] “Single Sign On (SSO) supported for Okta, Azure AD, SAML, and OIDC”
Deployment scale — stories about deployment scale in this arenaDeployment scale
Stories about deployment scale in this arena
Scale
platform-engineerSee documented concurrency limits and scale to many simultaneous calls without manual capacity begging
weight 2 · round drawnVapinone0/10No evidence pack items document concurrency limits, per-org call caps, autoscaling behavior, or capacity-request processes; the docs cover CLI, MCP server, tools, voices, and enterprise SSO but nothing about simultaneous-call scaling limits or how to raise them.
tellinone0/10No evidence pack item documents concurrency limits, per-account call caps, or scaling guarantees for simultaneous calls; docs mention dialing windows/retry strategy but not concurrency ceilings or auto-scaling behavior. This is a fair question for a voice-calling platform (scaling many simultaneous calls is core to the product's value), so 'none' applies rather than 'na'.
Self host
platform-engineerSelf-host the voice agent runtime from open-source code on my own infrastructure
weight 3 · round drawnVapinone0/10Vapi is presented entirely as a hosted SaaS platform with a CLI, MCP server, and dashboard for managing cloud-hosted assistants; there is no evidence of open-source runtime code or any self-hosting option. One community note even references that a different product (pipecat by daily.co) is the open-source alternative, implicitly contrasting with Vapi's closed hosted model.
- [community] “Vapi is also built on media framework by daily.co. They have an open source version of voice ai called pipecat.”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
Latency turntaking — stories about latency turntaking in this arenaLatency turntaking
Stories about latency turntaking in this arena
Latency
platform-engineerSee documented end-to-end voice latency numbers or tuning guidance backing the platform's speed claims
weight 3 · round to VapiVapi's docs mention that 'Ultra Fast' vs 'High Intelligence' model settings trade off latency, giving conceptual tuning guidance, but there are no documented end-to-end latency numbers (e.g., ms benchmarks) or detailed tuning playbooks in the evidence pack. Missing for 10: concrete latency benchmark figures, component-level latency breakdowns (STT/LLM/TTS), and independent verification of speed claims.
- [claimed-docs] “Ultra Fast uses speed-optimized models for lower latency. High Intelligence accepts higher latency for greater capability.”
Turn taking
developerRely on the agent to handle interruptions (barge-in) gracefully — stopping speech, updating context, and recovering the turn
weight 3 · round drawnVapinone0/10The evidence pack covers CLI, MCP server, tools, voices, compliance, and testing, but contains no documentation or evidence about interruption handling, barge-in behavior, context updates during interruptions, or turn recovery mechanics. This is a core latency/turn-taking capability for voice agents, but nothing in the pack addresses it directly.
developerEnable noise suppression or audio filtering so the agent stays coherent on noisy real-world calls
weight 1 · round drawnVapinone0/10No evidence pack items mention noise suppression, background noise filtering, or audio denoising features for handling noisy real-world calls; the pack covers voices, tools, CLI, MCP, latency modes, and testing but nothing about audio filtering.
developerUse model-based end-of-turn detection beyond simple VAD silence timeouts so the agent doesn't talk over slow speakers
weight 2 · round drawnVapinone0/10The evidence pack lacks any mention of model-based end-of-turn detection, turn-taking models, or semantic VAD alternatives; only latency tuning between 'Ultra Fast' and 'High Intelligence' model modes is documented, which does not address end-of-turn detection beyond silence-based VAD. Missing for 10: any documentation of a model-based or semantic end-of-turn detector, comparison to VAD-only timeout behavior, or configuration options for turn-taking sensitivity.
- [claimed-docs] “Ultra Fast uses speed-optimized models for lower latency. High Intelligence accepts higher latency for greater capability.”
Openness — open source, data portability, and self-hosting storiesOpenness
Open source, data portability, and self-hosting stories
ai-native userDo everything through the API that I can do in the UI
weight 2 · round to VapiVapi's API/SDK covers assistant, phone number, and call management, backed by a full CLI (vapi-docs-2 through 4, 27, 31-32, verified live in vapi-probe-rt-1) and an official MCP server exposing the same operations for external agents (vapi-docs-5,33, confirmed live and auth-gated in vapi-probe-rt-2). Dashboard-only conveniences like Voice Library browsing/preview remain UI-centric, though voice IDs and custom voices can be set via API (vapi-docs-9,24,26,35). Missing for 10: explicit confirmation that every dashboard-only feature (e.g., visual Voice Library browsing, HIPAA toggle) has a full API equivalent, and independent (non-vendor) verification of full UI/API parity.
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “vapi listen --forward-to localhost:3000/webhook”
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Build, test, and deploy voice AI applications without leaving your development environment.”
- [claimed-docs] “The CLI auto-detects your tech stack and sets up everything you need.”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
- [claimed-docs] “You can use your own custom voice with any supported provider by setting the `voice` property in your assistant configuration”
- [claimed-docs] “Browse and preview voices there, then copy a voice's ID to use on an assistant.”
telli exposes a REST API (with OpenAPI spec) covering contacts, scheduling calls, phone number import, custom tools, and webhooks, and also offers an MCP server so external AI tools can interact with Charlie. However, several UI-native features—agent builder/test-call dialog, live monitoring dashboard, side-by-side transcript/recording view, voice cloning setup, workflow trigger/recurring schedule configuration UI, and analytics dashboards—are not documented as API-accessible endpoints, so full UI/API parity is not evidenced. missing for 10: API endpoints for agent building/testing, live monitoring, voice cloning, workflow scheduling configuration, and analytics/reporting equivalent to UI dashboards.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “All endpoints authenticate with an API key from the telli app (Settings > Developer), sent as a bearer token”
- [claimed-docs] “Download them to generate client libraries, import the API into tools like Postman, or give coding agents machine-readable API context”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
- [claimed-docs] “Custom tools allow your AI agents to access external information by connecting to your APIs.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
ai-native userExport all of my data in open formats and leave
weight 3 · round drawnVapinone0/10No evidence of a data export feature, open-format data dumps, or account portability/deletion tooling; the docs cover CLI, MCP server, tools, and voice features but nothing about exporting assistants/call data/transcripts in open formats for user exit. Missing for 10: documented export functionality, open data formats supported, and any account/data portability guarantees.
tellinone0/10No evidence of a bulk data-export feature or open-format data portability; only API endpoints to manage/read specific records and a data-retention deletion policy are documented, not a full self-service export/leave capability. Missing for 10: documented full-account export tool/endpoint, open-format (CSV/JSON) bulk export, and any explicit data-portability statement.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Data retention deletes contacts and call data automatically once they reach an age you define.”
ai-native userRead the product's source under an open license
weight 2 · round drawnVapinone0/10Vapi is a closed, commercial SaaS platform; nothing in the evidence indicates its core source (server, dashboard, or model runtime) is published under an open license—only SDKs/CLI tooling and docs are mentioned, and the one open-source reference (pipecat) is a third-party project, not Vapi itself.
- [community] “Vapi is also built on media framework by daily.co. They have an open source version of voice ai called pipecat.”
ai-native userSelf-host the core product
weight 3 · round drawnVapinone0/10Vapi is presented exclusively as a hosted cloud platform (dashboard, hosted MCP server, hosted API/CLI against cloud endpoints); nothing in the evidence pack mentions a self-hostable core engine, open-source repo for the core product, or on-prem deployment option (the mentioned pipecat is a different open-source project, not Vapi itself). This is a fair axis for a voice-AI platform, but no evidence supports self-hosting.
- [community] “Vapi is also built on media framework by daily.co. They have an open source version of voice ai called pipecat.”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
Pricing plans — plan structure and value — what each tier costs and what it unlocksPricing plans
Plan structure and value — what each tier costs and what it unlocks
Pricing
founderSee published per-minute or usage pricing and estimate cost per call before committing
weight 2 · round drawnVapinone0/10The evidence pack contains no mention of pricing pages, per-minute rates, usage-based cost breakdowns, or any pricing calculator/estimator; all evidence is about docs, CLI, MCP server, tools, and testing features. Absence of evidence for this applicable axis yields none.
Privacy posture — data-handling and privacy storiesPrivacy posture
Data-handling and privacy stories
ai-native userChoose where my data is stored (region/residency)
weight 2 · round drawnVapinone0/10The evidence pack contains no mention of data residency, regional storage options, or geographic data controls anywhere in Vapi's docs (only HIPAA toggle and SSO/RBAC are mentioned as compliance features). Missing for 10: any documentation of region selection, data residency guarantees, or storage location controls.
ai-native userPrevent my data from being used to train AI models
weight 3 · round drawnVapinone0/10No evidence in the pack addresses data-training opt-out, model-training data policies, or privacy controls preventing AI training use; only HIPAA and SSO/RBAC enterprise features are mentioned, which are unrelated to this specific claim. missing for 10: explicit data-training opt-out policy, DPA/ToS language on training use, dashboard/API setting to exclude data from model training.
ai-native userControl data retention and deletion
weight 2 · round to telliVapinone0/10The evidence pack covers HIPAA, SSO/RBAC, tooling, CLI, and MCP server features but contains no documentation about data retention policies, call/recording deletion controls, or user-initiated data export/erasure mechanisms. Missing for 10: retention period settings, deletion/erasure APIs or dashboard controls, data export tools, and any policy documentation on how long call data/transcripts are stored.
telli documents automatic data retention deletion (contacts and call data purged once they reach a defined age) and conditional consent-based recording, giving users some control over data lifecycle and privacy. However, there's no evidence of user-initiated manual deletion, export/right-to-access tools, or granular per-record deletion controls beyond the age-based policy. missing for 10: manual/on-demand deletion controls, data export capability, independent verification of retention enforcement.
- [claimed-docs] “Data retention deletes contacts and call data automatically once they reach an age you define.”
- [claimed-docs] “In telli, you can easily make audio recording conditional on the caller's consent — so a call is only recorded once they agree.”
ai-native userOpt out of telemetry and usage tracking
weight 2 · round drawnVapinone0/10No evidence pack item addresses telemetry opt-out or usage tracking controls; Vapi's docs cover HIPAA/SSO/RBAC compliance but not a telemetry toggle.
tellinone0/10telli is a voice-agent platform, not a developer tool where telemetry opt-out is typically discussed, but the axis is still fair to ask (does the product track usage, and can a user disable it). The evidence pack (data retention, consent-based recording, etc.) never mentions any telemetry/usage-tracking opt-out mechanism for the product itself. Missing for 10: any documentation of telemetry collection practices or an opt-out setting/toggle.
Telephony — stories about telephony in this arenaTelephony
Stories about telephony in this arena
Call control
developerEscalate a live call to a human with warm or blind transfer, passing context along
weight 2 · round to telliVapinone0/10No evidence in the pack mentions call transfer, warm/blind transfer, or passing context to a human agent; the evidence covers assistants, CLI, MCP server, tools/webhooks, voices, and compliance, but nothing about live-call escalation/transfer capabilities.
Docs confirm a transfer tool that can move a call to another agent or number, matching the core escalation-to-human idea, but there's no mention of distinct warm vs. blind transfer modes or explicit context-passing to the human recipient. missing for 10: explicit warm/blind transfer distinction, evidence of context/data hand-off during transfer, hands-on confirmation of the feature in practice.
- [claimed-docs] “Transfer tools | Move the call to another agent or number.”
developerMy agent can send DTMF keypresses, navigate IVR menus, and detect or leave voicemail
weight 1 · round drawnVapinone0/10The evidence pack contains no mention of DTMF keypress sending, IVR menu navigation, or voicemail detection/leaving functionality anywhere in the docs or community items — these telephony-specific capabilities are entirely unevidenced despite being a plausible axis for a voice AI telephony product.
Campaigns
founderRun batch outbound call campaigns with scheduling and throughput controls
weight 2 · round to telliVapinone0/10Evidence covers assistant creation, tools, CLI, MCP server, testing, and voice customization, but nothing addresses batch/outbound campaign management, call scheduling, or throughput/concurrency controls for bulk dialing. No mention of a campaigns API, CSV/list upload, dialer pacing, or rate-limiting controls for outbound calling at scale.
telli documents dialing windows, calling strategies, and retry behavior (telli-docs-9) plus a schedule-call API endpoint that respects dialer windows or can bypass them (telli-docs-17, telli-docs-18) and reach-rate/success metrics (telli-docs-7), which together support scheduled, throughput-controlled outbound calling. However there is no explicit mention of a 'campaign' concept, bulk contact upload, or concurrency/rate limits for large batches. Missing for 10: explicit batch/campaign creation UI or endpoint, bulk contact import for calling, and documented concurrency/throughput limits beyond dialing windows.
- [claimed-docs] “Configure dialing windows, calling strategies, and retry behavior.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Optional flag to bypass dialing window restrictions for the scheduled call. When true, calls at the scheduled time regardless of dialing win…”
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
- [claimed-docs] “Workflows can now run automatically on a recurring schedule. Add a Scheduled trigger, choose the interval and start time, and let the workfl…”
Numbers
developerProvision phone numbers and run both inbound and outbound calls through the platform's API
weight 3 · round to VapiDocs explicitly cover creating an assistant, connecting it to a phone number, and making inbound/outbound calls via the quickstart, plus CLI/MCP support for managing phone numbers and calls, and SIP for advanced telephony integration, with runtime probes confirming the CLI and MCP endpoints work as documented. Missing for 10: independent hands-on confirmation of actual outbound call placement via raw API (only demo/inbound anecdote in community evidence) and explicit multi-number provisioning workflow details.
- [claimed-docs] “const assistant = await vapi.assistant”
- [claimed-docs] “Create a voice assistant, connect it to a phone number, and make your first calls.”
- [claimed-docs] “In under 5 minutes, you'll create a voice assistant and start talking to it over the phone.”
- [claimed-docs] “Manage assistants, phone numbers, and calls from your terminal”
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Use any SIP softphone (e.g., Zoiper, Linphone) to dial your SIP URI”
- [claimed-docs] “This guide shows you how to set up and test SIP calls to your Vapi assistant using any SIP client or softphone.”
- [probe] “PROBE runtime (recorded 2026-09-05): the official Vapi CLI installed via the vendor's one-liner (`curl -sSL https://vapi.ai/install.sh | bas…”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
- [community] “Called the demo number, sounds smooth! Good luck.”
telli's docs show a REST API with a schedule-call endpoint for outbound calls, an import-phone-number endpoint to bring SIP-trunk numbers under API control, webhooks for call events, and an OpenAPI spec confirming the API surface. However, inbound handling is documented mainly as manual forwarding/SIP trunk setup rather than a clear 'provision a new number via API' flow, and there's no explicit doc of purchasing/creating a fresh telli-hosted number through the API. missing for 10: a documented endpoint to provision/purchase brand-new phone numbers (not just import existing SIP trunk numbers), and clearer API-driven inbound call handling beyond forwarding.
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Schedules a call at the earliest opportunity within the dialer window. May occur immediately or on the next business day depending on settin…”
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “Keep your public business number and forward incoming calls to a telli number. You configure the forwarding with your phone provider or PBX.”
- [claimed-docs] “Connect an existing number and phone system for incoming and outgoing calls. You need SIP trunk access from your provider.”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
Sip
platform-engineerConnect my own carrier or PBX via SIP trunking (or import Twilio/Telnyx numbers) instead of being locked to bundled telephony
weight 2 · round to telliDocs confirm SIP connectivity: platform engineers can point any SIP client/softphone at a Vapi SIP URI to make/receive calls (vapi-docs-14, vapi-docs-22), which supports self-hosted/carrier SIP trunking use cases. However, the evidence never explicitly documents PBX/carrier trunk configuration options or a number-import workflow for Twilio/Telnyx accounts. missing for 10: explicit documentation of BYO-carrier/PBX trunk setup steps, and evidence of importing existing Twilio/Telnyx phone numbers into Vapi.
- [claimed-docs] “Use any SIP softphone (e.g., Zoiper, Linphone) to dial your SIP URI”
- [claimed-docs] “This guide shows you how to set up and test SIP calls to your Vapi assistant using any SIP client or softphone.”
Docs explicitly support importing numbers from a customer's own SIP trunk provider via a dedicated API endpoint, plus general SIP trunk connection for incoming/outgoing calls and call forwarding from an existing PBX/provider number. This directly matches the platform-engineer's need to bring their own carrier rather than being locked into bundled telephony. Missing for 10: no explicit mention of native Twilio/Telnyx number import (only generic SIP trunk import), and no independent/hands-on confirmation of the SIP trunk setup working in practice.
- [claimed-docs] “Imports a phone number from your own SIP trunk provider. This allows you to use existing phone numbers with telli by configuring custom SIP …”
- [claimed-docs] “Keep your public business number and forward incoming calls to a telli number. You configure the forwarding with your phone provider or PBX.”
- [claimed-docs] “Connect an existing number and phone system for incoming and outgoing calls. You need SIP trunk access from your provider.”
Testing analytics — stories about testing analytics in this arenaTesting analytics
Stories about testing analytics in this arena
Analytics
ai-native userThe platform's AI reviews my calls for me — scoring quality, flagging failures, and analyzing resolution automatically
weight 2 · round to telliVapi's Evals framework provides automated validation of assistant behavior via mock conversations and its Voice Test Suites use an AI tester to simulate calls and check outcomes, which is adjacent to automated call review, but neither is documented as automatically scoring, flagging failures in, or analyzing resolution of real production calls after the fact. Missing for 10: evidence of automatic post-call quality scoring on live/production transcripts, explicit failure-flagging analytics, and resolution-outcome analysis dashboards distinct from pre-production test suites.
- [claimed-docs] “Evals is Vapi's AI agent testing framework that enables you to systematically test assistants and squads using mock conversations with autom…”
- [claimed-docs] “you'll create mock conversations, define expected behaviors, and validate your agents work correctly before production”
- [claimed-docs] “Voice Test Suites enable you to test your AI voice agents through simulated phone conversations.”
- [claimed-docs] “Our AI tester calls your voice agent and follows a script that simulates real customer behavior.”
telli provides analytics like reach rate, success rate, call outcome fields, transcripts, and manual feedback submission for agent improvement, but there's no evidence of automated AI-driven quality scoring, failure flagging, or resolution analysis performed autonomously by the platform's AI — feedback and analysis appear human-driven rather than AI-automated review. missing for 10: automated AI scoring of call quality, automatic failure/anomaly flagging, AI-generated resolution analysis without human review.
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
- [claimed-docs] “Analyze individual calls, transcripts, and call outcome fields.”
- [claimed-docs] “Submit feedback on calls to continuously improve your agent.”
founderSee call analytics — success rates, durations, outcomes, sentiment — in dashboards without building my own
weight 2 · round to telliVapinone0/10The evidence pack documents assistant creation, tools, testing (Evals, Voice Test Suites), CLI/MCP management, and voice library features, but contains no mention of a dashboard showing call success rates, durations, outcomes, or sentiment analytics — the core of this story.
telli's docs describe built-in dashboards tracking reach rate, call duration, and success rate, plus per-call analysis of transcripts and outcome fields, and a live monitoring overview—covering most of the story without needing custom tooling. However, there is no explicit mention of sentiment analysis in dashboards. missing for 10: sentiment scoring/analysis in dashboards, independent/hands-on corroboration of dashboard usability.
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
- [claimed-docs] “Analyze individual calls, transcripts, and call outcome fields.”
- [claimed-docs] “Live Monitoring > Real-time call overview of your contacts”
Monitoring
platform-engineerMonitor live calls in production and get alerts when agents misbehave or error rates spike
weight 1 · round to telliVapinone0/10The evidence pack covers pre-production testing (Voice Test Suites, Evals) and webhook debugging via the CLI, but contains no mention of live call monitoring dashboards, real-time alerting, or error-rate-spike detection for production traffic. This is a fair axis for a voice AI platform, but nothing in the pack demonstrates it.
telli offers a real-time Live Monitoring call overview (telli-docs-32) and webhooks that push real-time notifications on call events/status/outcomes (telli-docs-13, telli-docs-21), which a platform engineer could wire into an alerting pipeline, plus metric tracking like success/reach rate (telli-docs-7). However there is no documented built-in alerting mechanism, error-rate-spike detection, or agent-misbehavior alerting system. Missing for 10: native alert/notification thresholds, anomaly or error-rate-spike detection, and evidence of alert delivery (email/Slack/PagerDuty) tied to live monitoring.
- [claimed-docs] “Live Monitoring > Real-time call overview of your contacts”
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “Track key metrics like reach rate, call duration, and success rate.”
Testing
developerTest agents with simulated conversations or evals before putting them on real phone calls
weight 2 · round to VapiVapi documents two dedicated testing features directly matching the story: Voice Test Suites for simulated phone conversations via an AI tester following scripted customer behavior, and Evals, a testing framework for mock conversations with automated validation before production. Missing for 10: independent/hands-on developer corroboration of these specific testing features beyond vendor docs.
- [claimed-docs] “Voice Test Suites enable you to test your AI voice agents through simulated phone conversations.”
- [claimed-docs] “Our AI tester calls your voice agent and follows a script that simulates real customer behavior.”
- [claimed-docs] “Evals is Vapi's AI agent testing framework that enables you to systematically test assistants and squads using mock conversations with autom…”
- [claimed-docs] “you'll create mock conversations, define expected behaviors, and validate your agents work correctly before production”
telli's agent builder includes a 'Test call' feature to trial a draft or saved agent version and review the recording/transcript side-by-side before going live, which covers pre-production testing, and feedback submission helps iterate on agent quality. However, there is no evidence of simulated/synthetic conversation runs, automated eval suites, or scripted test scenarios independent of an actual phone call. Missing for 10: automated evals framework, non-call simulated conversation testing, batch/regression testing tools.
- [claimed-docs] “In the agent builder, click Test call to open the dialog. Pick the agent version (your draft with unsaved changes or any saved revision)...”
- [claimed-docs] “Use the side-by-side view to listen to the recording while following along in the transcript.”
- [claimed-docs] “Submit feedback on calls to continuously improve your agent.”
Tools function calling — stories about tools function calling in this arenaTools function calling
Stories about tools function calling in this arena
Post call
developerExtract structured data from every call — outcomes, entities, dispositions — delivered via API or webhook after the call
weight 2 · round to telliVapinone0/10The evidence pack shows Vapi's webhook/tool-calling system for live in-call actions (tool-calls messages, custom webhook tools, function calling) but contains no mention of a post-call structured-data/analysis feature (outcomes, entities, dispositions) delivered via API or webhook after the call ends. Missing for 10: any docs on end-of-call reports, structured data extraction schemas, call analysis/summary webhooks, or an API endpoint returning call outcome/entity data.
- [claimed-docs] “When tools are triggered, your Server URL receives a `tool-calls` message”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
telli documents webhooks pushing real-time call event/status/outcome data and a REST API for programmatic access, plus conversation views showing appointment/outcome fields and call outcome analysis, supporting structured post-call data delivery. However, there's no explicit documentation of a structured schema for entities/dispositions extraction or example payloads showing the full breadth of structured fields promised. missing for 10: example webhook/API payload showing structured entities and disposition fields, documentation of a dedicated 'call outcomes' data model, independent/hands-on confirmation of data completeness.
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [claimed-docs] “Analyze individual calls, transcripts, and call outcome fields.”
- [claimed-docs] “Conversations now show appointments saved during a call, including the time, status, hosts, and provider link.”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
Tools
ai-native userMy voice agent can plug in MCP servers as tool sources so one integration grants it whole toolsets mid-call
weight 2 · round drawnVapinone0/10Evidence only shows Vapi exposing its own APIs as an MCP *server* for external AI assistants (e.g., Claude Desktop) to manage calls/assistants — the reverse direction of the story. There is no documentation or probe showing a Vapi voice assistant can itself act as an MCP *client*, plugging in external MCP servers as tool sources mid-call; tool integration is instead described only via webhook-based custom tools and OpenAI-style function calling.
- [claimed-docs] “so you can manage assistants, phone numbers, and calls from any MCP-compatible AI assistant (like Claude Desktop) or agent framework”
- [claimed-docs] “The Vapi MCP Server exposes Vapi APIs as tools via the Model Context Protocol (MCP), so you can manage assistants, phone numbers, and calls …”
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [probe] “PROBE runtime (recorded 2026-09-05): keyless JSON-RPC initialize POST to the hosted MCP server https://mcp.vapi.ai/mcp returned HTTP 401 — t…”
tellinone0/10telli documents custom tools connecting to external APIs (telli-docs-20) and even an MCP server (telli-docs-22, telli-probe-3), but that MCP server lets external AI tools like Claude/ChatGPT talk to telli's Charlie assistant — it is telli acting as an MCP server, not the voice agent consuming external MCP servers as a tool source mid-call. There is no evidence the voice agent itself can plug in MCP servers to gain toolsets during a call.
- [claimed-docs] “The telli MCP server lets AI tools like Claude, ChatGPT, and Codex talk to Charlie, telli's AI assistant, over the Model Context Protocol.”
- [probe] “official MCP server documented at https://docs.telli.com/integrations/mcp”
- [claimed-docs] “Custom tools allow your AI agents to access external information by connecting to your APIs.”
developerMy agent can call external APIs and custom functions mid-conversation and speak the result without awkward dead air
weight 3 · round drawnVapi's docs clearly show mid-call function/tool calling via webhook Server URLs and OpenAI-style tool-calls messages, letting the assistant fetch external API results and use them in conversation (vapi-docs-6, vapi-docs-7, vapi-docs-17, vapi-docs-20, vapi-docs-23, vapi-docs-34). However, the pack lacks explicit evidence about mechanisms for avoiding 'dead air' during the API call latency (e.g., async tool config, filler phrases, or interim speech) — only general latency-tuning docs for model selection are present (vapi-docs-15). Missing for 10: explicit documentation/demo of filler/interim speech or async tool handling during function execution, and independent hands-on confirmation that the conversation flow feels seamless during a live tool call.
- [claimed-docs] “Create your own webhook-based tools to extend assistant capabilities”
- [claimed-docs] “Server URL: The endpoint where your function is hosted”
- [claimed-docs] “When tools are triggered, your Server URL receives a `tool-calls` message”
- [claimed-docs] “This guide shows you how to create custom tools, including Function Tools, for your Vapi assistants.”
- [claimed-docs] “Vapi supports OpenAI-style tool/function calling. Assistants can ping your server to perform actions.”
- [claimed-docs] “Custom tools that you create... interact with your systems via webhooks”
- [claimed-docs] “Ultra Fast uses speed-optimized models for lower latency. High Intelligence accepts higher latency for greater capability.”
Docs confirm custom tools let agents call external APIs mid-call (telli-docs-20) and built-in tool calls like web_search operate during live calls (telli-docs-30), plus transfer tools show mid-call action execution (telli-docs-31). However, there is no documentation addressing latency masking or filler-speech to avoid 'dead air' while awaiting API responses. missing for 10: explicit evidence of latency-hiding/filler speech during tool calls, independent hands-on confirmation of smooth voice continuity.
- [claimed-docs] “Custom tools allow your AI agents to access external information by connecting to your APIs.”
- [claimed-docs] “For a Duo agent, open Tools > System and enable web_search to let the agent search the web for current public information during calls.”
- [claimed-docs] “Transfer tools | Move the call to another agent or number.”
Transcription recording — stories about transcription recording in this arenaTranscription recording
Stories about transcription recording in this arena
Recording
platform-engineerRetrieve full call recordings and transcripts programmatically for every call
weight 2 · round to telliVapinone0/10The evidence pack contains no documentation, API reference, or example demonstrating retrieval of call recordings or transcripts, despite this being a natural, expected capability for a voice AI platform; only tangential tooling (CLI, MCP server, custom tools, testing/evals) is covered.
Docs confirm transcripts and recordings exist and can be reviewed in-app (side-by-side view, consent-based recording) and telli exposes a general REST API plus webhooks for call events, but no endpoint is documented that explicitly returns full call recordings or transcripts programmatically for every call. missing for 10: a documented GET/recording or GET/transcript API endpoint, confirmation of bulk/enumerable retrieval, and independent verification that recordings are accessible via the API rather than only in the UI.
- [claimed-docs] “Analyze individual calls, transcripts, and call outcome fields.”
- [claimed-docs] “Use the side-by-side view to listen to the recording while following along in the transcript.”
- [claimed-docs] “In telli, you can easily make audio recording conditional on the caller's consent — so a call is only recorded once they agree.”
- [claimed-docs] “API Endpoints: Use telli's REST API to programmatically manage contacts, schedule calls, and integrate with your existing systems.”
- [claimed-docs] “Webhooks: Receive real-time notifications about call events, status changes, and outcomes.”
- [claimed-docs] “Webhooks push data from telli to your systems in real time. When something happens on a call, telli sends a POST request to the endpoint you…”
- [probe] “PROBE openapi: HTTP 200 at https://docs.telli.com/openapi.json — contains "openapi" key”
Transcription
developerGet accurate real-time transcription with control over the STT provider, language models, or key terms
weight 2 · round drawnVapinone0/10The evidence pack contains no documentation about selecting/configuring an STT provider, choosing language models for transcription, or defining custom key terms/vocabulary for real-time transcription — topics like 'transcriber', 'Deepgram', or keyword boosting are absent. While Vapi is clearly a voice AI platform where such controls are a fair axis, none of the provided docs, community items, or probes address it.
tellinone0/10telli documents transcript viewing and side-by-side playback (telli-docs-29) but provides no evidence of developer-facing control over STT provider selection, choice of underlying language models, or custom key-term/vocabulary boosting for transcription accuracy.
- [claimed-docs] “Use the side-by-side view to listen to the recording while following along in the transcript.”
Voices tts — stories about voices tts in this arenaVoices tts
Stories about voices tts in this arena
Voices
founderClone a custom brand voice and use it for my agents, with a documented consent process
weight 2 · round to telliVapinone0/10Vapi docs show you can plug in a 'custom voice' by setting the voice property with a provider ID (vapi-docs-9, vapi-docs-26) and browse a Voice Library (vapi-docs-8, vapi-docs-35), but nothing describes an actual voice-cloning workflow or any documented consent/verification process required before cloning a brand voice. Missing for 10: a described voice-cloning feature/flow, a documented consent or identity-verification process, and any policy language governing voice cloning.
- [claimed-docs] “You can use your own custom voice with any supported provider by setting the `voice` property in your assistant configuration”
- [claimed-docs] “You can use your own custom voice with any supported provider by setting the voice property in your assistant configuration”
- [claimed-docs] “The Voice Library in the Vapi Dashboard lists every voice available to your organization. Browse and preview voices there”
- [claimed-docs] “The **Voice Library** in the [Vapi Dashboard] lists every voice available to your organization. Browse and preview voices there, then copy a…”
Voice cloning is documented as a real feature (telli-docs-27) letting founders give agents a custom voice, but the pack's only consent-related documentation concerns call recording consent (telli-docs-26), not a consent process specifically for cloning someone's voice. Missing for 10: explicit documented consent/authorization workflow for the voice being cloned (e.g., proof of rights from the voice owner), and any legal/compliance guardrails for cloning third-party voices.
- [claimed-docs] “Voice cloning lets you give your agent a custom voice (your own, a colleague's, or a professional voice actor's), so the agent sounds exactl…”
- [claimed-docs] “In telli, you can easily make audio recording conditional on the caller's consent — so a call is only recorded once they agree.”
developerChoose from a broad voice library or plug in multiple TTS providers to get the voice I want
weight 2 · round to VapiDocs confirm a Voice Library with many previewable voices and support for custom voices with any supported provider, indicating multi-provider TTS flexibility, but the evidence never names or lists specific TTS providers (e.g., ElevenLabs, PlayHT, Azure) or details plugging in third-party/custom TTS engines beyond voice ID selection. missing for 10: explicit list of supported TTS providers, documentation of custom/BYO TTS provider integration mechanics, independent hands-on confirmation of voice quality/variety.
- [claimed-docs] “The Voice Library in the Vapi Dashboard lists every voice available to your organization. Browse and preview voices there”
- [claimed-docs] “You can use your own custom voice with any supported provider by setting the `voice` property in your assistant configuration”
- [claimed-docs] “Browse and preview voices there, then copy a voice's ID to use on an assistant.”
- [claimed-docs] “You can use your own custom voice with any supported provider by setting the voice property in your assistant configuration”
- [claimed-docs] “The **Voice Library** in the [Vapi Dashboard] lists every voice available to your organization. Browse and preview voices there, then copy a…”
Docs mention voice cloning to give an agent a custom voice, but there is no evidence of a curated voice library to choose from or the ability to plug in multiple external TTS providers as the story requires. missing for 10: evidence of a selectable voice library, multi-provider TTS integration, developer API/config for switching TTS engines.
- [claimed-docs] “Voice cloning lets you give your agent a custom voice (your own, a colleague's, or a professional voice actor's), so the agent sounds exactl…”