Retell AI vs telli
Retell AI
Retell AI
Retell AI wins · 25–9 (27 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 Retell AIRetell ships an official Node/Python SDK with full voice endpoint coverage, a CLI for managing agents and phone numbers, and an MCP server whose meta-tools (list/get/invoke_api_endpoint) expose the entire API — including agent create/update/publish — to MCP clients like Cursor or Claude Code, and a keyless runtime probe confirms the MCP handshake works end-to-end. However, the flagship quick-start walkthrough is dashboard-centric (create in UI, assign number in 'configuration settings', test/call via dashboard button), and no evidence explicitly shows a CLI/API/MCP call sequence that attaches a number and places a live call without touching the UI. Missing for 10: an explicit end-to-end CLI/MCP example showing number-attach and call-placement commands, and independent confirmation that non-dashboard number provisioning/outbound calling works in practice.
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
- [claimed-docs] “Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude D…”
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [claimed-docs] “Assign your agent to the number in the configuration settings”
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 drawnRetell docs mention a 'Generate from prompt' feature where Conductor drafts an agent from a plain-English description (retell-docs-30), directly supporting AI-assisted agent authoring. However, there's no evidence of AI-driven improvement of existing prompts/flows or automatic test-case generation, and no independent/hands-on confirmation of Conductor's output quality. Missing for 10: documentation on iterative prompt/flow refinement by the platform's AI, automated test-case generation, and community or hands-on verification of Conductor's generated agents.
- [claimed-docs] “click **Generate from prompt** (marked Suggested) to let [Conductor](/conductor/create-agent) draft an agent from a plain-English descriptio…”
- [claimed-docs] “Retell agents are node-based flows or single prompts, with call handling, a knowledge base, and integrations built in.”
- [claimed-docs] “Drag-and-drop, node-based flows for structured, high-stakes calls.”
- [claimed-docs] “Single prompt agent... Define your whole agent with one prompt.”
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 Retell AIDocs walk through the exact flow described: create account, pick/generate a template, set prompt and voice, test in dashboard, assign a phone number, and make a live call, with a 15-minute quickstart and free trial credits removing payment friction. Community feedback confirms the demo/agent works end-to-end for real calls, though it also shows occasional conversational glitches (contradictions, confusion) that are quality issues rather than build-flow blockers. missing for 10: independent third-party timing confirmation that a full build-to-first-call truly completes within an hour, and evidence of phone-number provisioning speed in practice.
- [claimed-docs] “Build your first Retell AI phone agent in 15 minutes: create an account, pick a template, test in the dashboard, deploy to a phone number, a…”
- [claimed-docs] “Click the "Test" button to start a web call with your agent... This step is free and doesn't need a phone number or payment method.”
- [claimed-docs] “click **Generate from prompt** (marked Suggested) to let [Conductor](/conductor/create-agent) draft an agent from a plain-English descriptio…”
- [claimed-docs] “Click the "Test" button to start a web call with your agent”
- [claimed-docs] “Assign your agent to the number in the configuration settings”
- [claimed-docs] “New accounts start with \$10 in free trial credits, no payment method required.”
- [claimed-docs] “Add custom voices to your Retell agent — search ElevenLabs community voices, import a voice clone, or train a clone for a unique brand-speci…”
- [community] “Curious what model the dentist bot is running on? Tried it out, was surprisingly good, though eventually it contradicted itself (booked a sl…”
- [community] “I tried to fool the Dental Office demo trying to book on Sunday or outside of the slots it had indicated, and it did a better job than many …”
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 drawnRetell AInone0/10No documentation in the evidence pack describes multi-language conversation support, language detection, or mid-call language switching; the only related evidence is a founder comment stating multilingual support is merely 'on our roadmap' rather than shipped, indicating the capability does not currently exist.
- [community] “Founder said multilingual support is on roadmap: 'It's definitely in our roadmap. After the core product—the voice AI part—becomes humanlike…”
founderDesign multi-step conversation flows in a visual builder with branching, states, and handoffs without writing code
weight 2 · round to Retell AIRetell's docs describe node-based, drag-and-drop conversation flows for 'structured, high-stakes calls' as an alternative to single-prompt agents, with function calling enabling transfers, call-ending, and API calls that serve as handoff points — directly matching the branching/states/handoff story without requiring code. The quick-start flow (pick template, test in dashboard, deploy) reinforces a no-code workflow. Missing for 10: independent/hands-on evidence of the visual builder's branching UI itself (community evidence only covers conversational behavior, not the builder), and no detail on how 'states' are represented/connected beyond the general node-based description.
- [claimed-docs] “Retell agents are node-based flows or single prompts, with call handling, a knowledge base, and integrations built in.”
- [claimed-docs] “Drag-and-drop, node-based flows for structured, high-stakes calls.”
- [claimed-docs] “Single prompt agent... Define your whole agent with one prompt.”
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
- [claimed-docs] “Build your first Retell AI phone agent in 15 minutes: create an account, pick a template, test in the dashboard, deploy to a phone number, a…”
- [claimed-docs] “click **Generate from prompt** (marked Suggested) to let [Conductor](/conductor/create-agent) draft an agent from a plain-English descriptio…”
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 drawnRetell AInone0/10The evidence pack covers function calling, webhooks, custom telephony, knowledge base retrieval, CRM field sync, and SDK/CLI/MCP tooling, but nowhere describes injecting dynamic variables or per-caller context (e.g., a startCall/create-call parameter for passing caller-specific data into the prompt/LLM at runtime). This is a fair, plausible capability for a voice-agent platform, so absence of evidence yields 'none' rather than 'na'.
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 to Retell AIRetell explicitly ships a knowledge base feature where you can crawl websites or upload documents for the agent to retrieve from, and AI QA scores 'knowledge base accuracy' as a call metric, confirming grounding is a first-class capability. However, evidence is thin — only brief homepage-level mentions rather than a dedicated deep-dive doc on KB architecture/RAG internals, and there's no independent/hands-on confirmation of retrieval quality. Missing for 10: dedicated knowledge-base documentation page detailing chunking/retrieval mechanics, and independent verification that answers are accurately grounded in uploaded content.
- [claimed-docs] “Retell agents are node-based flows or single prompts, with call handling, a knowledge base, and integrations built in.”
- [claimed-docs] “Crawl a website or upload documents your agent retrieves from.”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
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 drawnA direct probe confirms an llms.txt file exists at docs.retellai.com/llms.txt returning HTTP 200 with a structured index of the docs, and Retell's docs are also agent-oriented enough to support MCP-based discovery/management of resources. This directly satisfies the story of pointing an agent at llms.txt or agent-oriented docs. Missing for 10: no independent third-party corroboration of llms.txt usage in the wild.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.retellai.com/llms.txt # Retell AI > Explore Retell AI docs to learn how to build, test, deploy, an…”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
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 to Retell AIRetell ships official Node.js/Python SDKs with API-key auth and a terminal CLI for managing agents, phone numbers, and resources, both of which are scriptable outside the dashboard, and a runtime probe confirms the CLI installs and runs keylessly via npm — all consistent with headless/CI use. However, there is no explicit CI/automation documentation (e.g., GitHub Actions example, testing-in-pipeline guide) confirming an officially supported headless workflow. Missing for 10: explicit CI/pipeline documentation or example, confirmation of non-interactive auth flow for CI secrets, and independent evidence of real-world CI usage.
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “The Retell CLI lets you manage Retell resources from your terminal.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “official CLI documented at https://docs.retellai.com/get-started/cli”
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 to Retell AIRetell explicitly documents connecting a live voice/chat agent to a remote MCP server so it can invoke that server's tools during calls, directly matching the story of plugging in external MCP servers for tool use. This is a first-party, well-specified capability (not just Retell exposing its own API as MCP) covering both single- and multi-prompt agents. Missing for 10: independent/hands-on verification that a third-party MCP server's tools work reliably mid-call in production.
- [claimed-docs] “Connect a Retell single- or multi-prompt agent to a remote MCP server so it can call the server's tools during a live voice or chat conversa…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote Model Context Protocol (MCP) server, and the agent can call that server's tools durin…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote [Model Context Protocol (MCP)] server, and the agent can call that server's tools dur…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
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 Retell AIRetell documents and hosts an official MCP server (mcp.retellai.com) that lets MCP-capable clients like Cursor, Claude Desktop, and Claude Code build and manage Retell voice agents via the Retell API, exposing meta-tools for listing/invoking endpoints. A runtime probe confirms the server completes a full keyless JSON-RPC initialize handshake and exposes its tool set, corroborating the vendor docs. Missing for 10: independent/community usage reports of the MCP server in practice beyond vendor docs and the probe.
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
- [claimed-docs] “Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude D…”
- [claimed-docs] “Retell supports the [Model Context Protocol (MCP)] so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude…”
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
- [probe] “official MCP server documented at https://docs.retellai.com/get-started/mcp-server”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 Retell AIRetell ships an official CLI (`@retell-ai/retell-cli`) documented for managing agents, phone numbers, and knowledge bases from the terminal, and a runtime probe confirms it installs and runs keylessly via npx. Missing for 10: independent/community usage reports of the CLI itself (only docs and one probe run corroborate it).
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “The Retell CLI lets you manage Retell resources from your terminal.”
- [probe] “official CLI documented at https://docs.retellai.com/get-started/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
ai-native userDrive the product through a documented public API
weight 3 · round drawnRetell documents official Node.js/Python SDKs with typed clients and full endpoint coverage, a CLI for managing resources from the terminal, and API references (e.g., clone-voice endpoint) — and a runtime probe confirms the CLI installs/runs keylessly and the hosted MCP server exposes the entire API via meta-tools, proving the API is genuinely agent-drivable. Missing for 10: a publicly discoverable OpenAPI/swagger spec (all standard paths returned 404 in the probe).
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [claimed-docs] “Type safety: Full TypeScript support with autocomplete ... Error handling: Structured error responses with detailed messages”
- [probe] “official MCP server documented at https://docs.retellai.com/get-started/mcp-server”
- [probe] “official CLI documented at https://docs.retellai.com/get-started/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.retellai.com/openapi.json, https://docs.retellai.com/swagger.json, https://docs.retella…”
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 drawnRetell AInone0/10The evidence pack documents API key auth, SDKs, CLI, and an MCP server, but nowhere describes scoped, role-based, or least-privilege API key/credential issuance (e.g., per-agent or per-permission keys) for Retell. This is a fair axis for an API/voice-agent platform, but no docs or probes show scoped credential support, so it is unproven.
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
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 Retell AIRetell documents and ships official typed SDKs for Node.js and Python with API key auth, full endpoint coverage, structured errors, and TypeScript autocomplete, plus an official CLI and MCP server for programmatic/agentic access — all independently confirmed by runtime probes (CLI installs and runs, MCP server completes handshake). Missing for 10: no independent third-party review of SDK quality/DX beyond vendor docs and no public OpenAPI spec discovered.
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [claimed-docs] “Type safety: Full TypeScript support with autocomplete ... Error handling: Structured error responses with detailed messages”
- [probe] “official CLI documented at https://docs.retellai.com/get-started/cli”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “official MCP server documented at https://docs.retellai.com/get-started/mcp-server”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 drawnRetell has dedicated first-party documentation for webhooks describing real-time event notifications pushed to your application as events occur, enabling event-driven integrations rather than polling — directly matching the story of subscribing to events via webhooks. Missing for 10: no independent/hands-on corroboration of webhook reliability or event catalog completeness beyond the docs themselves.
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
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 drawnRetell's AI QA feature automatically scores calls on hallucination, knowledge-base accuracy, latency, sentiment, and tool usage to surface quality trends and issues, and custom analytics dashboards let users chart/filter call and chat metrics — both are AI-derived insights from the product's own call data. However, this is scoring/quality analytics rather than proactive generative 'suggestions' (e.g., recommended actions, next-best-response, or coaching tips), and there's no independent/hands-on evidence validating the accuracy or usefulness of these AI-generated insights. Missing for 10: evidence of proactive suggestion/recommendation generation beyond scoring, and third-party corroboration of AI QA insight quality.
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “Built-in call success and sentiment scoring, plus custom fields synced to your CRM.”
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 telliRetell agents act autonomously during live calls — function calling lets them independently book appointments, send SMS, transfer calls, and call external APIs without human intervention (retell-docs-5, retell-docs-35), and webhooks push real-time events to downstream systems (retell-docs-12, retell-docs-24). This shows in-call autonomous action-taking, which is a form of background automation once a call is triggered. However, there's no evidence of standalone scheduled/triggered automations running independent of a live voice/chat session (e.g., cron-like outbound campaigns or autonomous multi-step workflows outside conversation context). Missing for 10: evidence of scheduled or event-triggered background automations outside live calls, and independent/hands-on confirmation that autonomous function-calling reliably completes tasks unattended (community reports show some confusion/looping during autonomous task execution, retell-comm-1, retell-comm-3, retell-comm-5).
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
- [community] “The AI contradicted itself when layering conditionals - it got confused about morning vs afternoon time, kept asking to repeat despite corre…”
- [community] “Voice sounds great, but: told it unavailable until next year, it confirmed Feb 4th 'next year' but thought current year was 2022. Also got s…”
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 telliRetell's dashboard includes 'Conductor', a built-in AI assistant that can draft an entire agent from a plain-English prompt (docs-30), which is a genuine instance of delegating a task to an in-product AI assistant. However this is a single thin mention with no further detail on scope, limits, or other delegable tasks beyond initial agent creation. Missing for 10: documentation of Conductor's full capabilities/limits, evidence of delegating other tasks (not just agent drafting) to a built-in assistant, and independent/hands-on corroboration of Conductor actually working.
- [claimed-docs] “click **Generate from prompt** (marked Suggested) to let [Conductor](/conductor/create-agent) draft an agent from a plain-English descriptio…”
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 Retell AIRetell supports natural-language operation via Conductor's 'Generate from prompt' feature that drafts an agent from a plain-English description, and via its official MCP server which exposes the full API as agent-callable tools so AI-native clients (Cursor, Claude Desktop, Claude Code) can build/manage agents through natural-language MCP tool calls — confirmed live by a keyless JSON-RPC probe against the hosted MCP endpoint. missing for 10: independent/hands-on evaluation of Conductor's prompt-to-agent quality, and no evidence of NL commands for other everyday operations (e.g., dashboard chat-based control) beyond agent creation/management.
- [claimed-docs] “click **Generate from prompt** (marked Suggested) to let [Conductor](/conductor/create-agent) draft an agent from a plain-English descriptio…”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
- [claimed-docs] “Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude D…”
- [claimed-docs] “Retell supports the [Model Context Protocol (MCP)] so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude…”
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
- [probe] “official MCP server documented at https://docs.retellai.com/get-started/mcp-server”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 telliRetell AInone0/10Evidence shows Retell has API reference doc pages (e.g., api-references/clone-voice.md) and SDKs/CLI/MCP tooling, but no evidence of an interactive, runnable API reference (e.g., embedded 'try it' console or Swagger UI). The probe explicitly found no OpenAPI/Swagger spec exposed (all candidate paths 404), undermining any claim of an interactive reference.
- [claimed-docs] “Clone a voice from audio files”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.retellai.com/openapi.json, https://docs.retellai.com/swagger.json, https://docs.retella…”
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 telliRetell AInone0/10A direct probe for standard OpenAPI/Swagger spec locations (openapi.json, swagger.json, etc.) on Retell's docs domain returned 404 for all candidates, and no evidence pack item shows a downloadable, machine-readable API spec being published or linked from docs. The CLI's version string mentions an internal 'OpenAPI 3.0.0' schema, but this is not shown to be an artifact users can download or fetch programmatically.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.retellai.com/openapi.json, https://docs.retellai.com/swagger.json, https://docs.retella…”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
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 drawnRetell's quick-start lets you click 'Test' to run a free web call with your agent before it ever touches a phone number or payment method, and new accounts get $10 trial credit to experiment risk-free — a lightweight way to try an agent without production telephony traffic. However, there's no documented dedicated sandbox environment, test-mode API flag, or explicit data isolation guarantee separating test calls from production records/analytics. Missing for 10: explicit sandbox/staging environment concept, test vs prod data isolation guarantees, and independent confirmation that test-call data doesn't mix with production analytics/QA.
- [claimed-docs] “Click the "Test" button to start a web call with your agent... This step is free and doesn't need a phone number or payment method.”
- [claimed-docs] “Click the "Test" button to start a web call with your agent”
- [claimed-docs] “New accounts start with \$10 in free trial credits, no payment method required.”
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 drawnRetell AInone0/10The evidence pack covers SDKs, CLI, MCP server, and API endpoints extensively, but there is no documentation of API versioning scheme or a deprecation policy for breaking changes. The probe notes an OpenAPI version string (3.0.0, catalog v4) but this is not evidence of a documented deprecation/versioning policy for API consumers.
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 telliRetell exposes a full-coverage SDK, CLI, and MCP server that let an AI agent script repeated single-item operations (create/update/list agents, phone numbers, knowledge bases) programmatically, enabling scripted bulk-like loops, but there is no documented native batch/bulk endpoint operating on many items in a single call. missing for 10: explicit batch/bulk API endpoints or CLI commands operating on multiple items in one call, evidence of rate-limit-safe bulk workflows, and hands-on confirmation of bulk usage at scale
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
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 to Retell AIRetell supports event-driven automation via webhooks that fire on account events (retell-docs-12, retell-docs-24), function calling that lets agents automatically transfer calls, end calls, book appointments, or call external APIs based on conversation logic (retell-docs-5, retell-docs-35), and node-based flows with conditional branching (retell-docs-25) plus AI QA rules evaluated against configured metrics (retell-docs-43). However, this is scattered across call-flow logic and webhook notifications rather than a unified 'if event then action' rule-definition interface. Missing for 10: a dedicated rules/trigger engine UI for arbitrary account-wide events, documentation of webhook-to-action automation chains, and independent verification that rule-based automation works reliably (community reports note conversational logic errors, e.g. retell-comm-1, retell-comm-3, retell-comm-7).
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
- [claimed-docs] “Drag-and-drop, node-based flows for structured, high-stakes calls.”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
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 telliRetell AInone0/10Retell's docs cover webhooks, function calling, MCP tool-calling, and telephony integration, but nothing describes scheduling recurring jobs, campaigns, or workflows (e.g., cron-like recurring outbound call batches or repeating automations). This is a fair question for a voice-agent platform (buyers often want scheduled/recurring outbound campaigns), so the axis applies, but no evidence in the pack shows this capability. missing for 10: any mention of a scheduler, recurring campaign/job feature, or cron-style automation trigger.
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 Retell AIRetell supports 'agent versions' with create/update/publish/list/fetch operations via CLI and MCP (retell-docs-47), implying some versioning and possibly rollback via republishing an older version, but there is no documented review workflow (diffs, approvals, changelogs) or explicit rollback command/UI. missing for 10: explicit rollback mechanism, version diff/review UI, changelog or audit trail, and any independent/hands-on confirmation that version history and rollback actually work as described.
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
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 telliRetell documents per-agent configurable data retention that auto-deletes transcripts, recordings, and logs after a set period, directly addressing retention obligations. However, there is no evidence of explicit per-call recording enable/disable controls or built-in consent-disclosure features (e.g., automated recording announcements) that founders would need for two-party consent compliance. Missing for 10: per-call recording on/off toggle, consent-disclosure/announcement mechanism, and any documentation tying these to legal consent requirements.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
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 drawnRetell AInone0/10Evidence shows only generic data-retention controls (docs-15/27/44) but no mention of HIPAA, BAA, SOC 2 certification, or data-residency options anywhere in the docs or community pack, despite this being a fair compliance axis for a voice-AI platform handling call recordings/transcripts.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
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 to Retell AIRetell documents a concurrency configuration feature (reserved inbound concurrency vs. outbound limit) showing platform-level concurrency controls exist, but there is no documented default/numeric concurrency limits per plan, no described self-service process to raise limits without contacting support, and no evidence (docs or community) confirming scaling to many simultaneous calls happens without manual requests. missing for 10: published default concurrency limits, self-service limit-increase mechanism, and independent confirmation of large-scale concurrent call handling without support intervention.
- [claimed-docs] “Reserved inbound concurrency protects inbound calls from being crowded out by outbound traffic.”
- [claimed-docs] “When `reserved_inbound_concurrency` is configured, outbound calls can use at most your concurrency limit minus the reserved amount.”
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 drawnRetell AInone0/10Retell AI is a hosted SaaS voice-agent platform; all evidence points to cloud-hosted APIs, SDKs, CLI, and MCP server that call Retell's own servers, with no mention of open-source runtime code or self-hosting instructions. There is no evidence a platform-engineer can download and run the voice agent runtime on their own infrastructure.
- [claimed-docs] “Build your first Retell AI phone agent in 15 minutes: create an account, pick a template, test in the dashboard, deploy to a phone number, a…”
- [claimed-docs] “Retell starts at $0, pay only for what you use.”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 Retell AIRetell docs offer tuning guidance for latency (transcription mode trade-offs, endpointing settings) and let customers monitor latency via analytics dashboards and AI QA scoring, but there are no documented end-to-end latency benchmarks or numbers substantiating speed claims. missing for 10: published end-to-end latency figures/benchmarks, and independent verification of speed claims.
- [claimed-docs] “Pick the right Retell transcription mode to balance accuracy against latency — interim results for speed or context-aware results for higher…”
- [claimed-docs] “Real time transcription is often a trade off between latency and accuracy.”
- [claimed-docs] “optimize for speed: uses the latest interim results with a low endpointing setting... optimize for accuracy: uses the results with a higher …”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
Turn taking
developerRely on the agent to handle interruptions (barge-in) gracefully — stopping speech, updating context, and recovering the turn
weight 3 · round drawnRetell AInone0/10The evidence pack covers transcription latency/accuracy trade-offs (retell-docs-9, retell-docs-39, retell-docs-48) but nowhere describes explicit barge-in/interruption handling — stopping agent speech, updating context, and recovering the turn when a caller interrupts. Community threads show turn-taking confusion (contradictions, loops, disconnects) but do not address interruption handling specifically. Missing for full/partial credit: any documentation or hands-on report confirming barge-in detection, speech-stop behavior, or turn recovery mechanics.
developerEnable noise suppression or audio filtering so the agent stays coherent on noisy real-world calls
weight 1 · round drawnRetell AInone0/10No evidence pack item mentions noise suppression, background-noise filtering, or audio-preprocessing features for handling noisy real-world call environments; the closest related feature (transcription-mode trade-off between latency and accuracy) addresses turn-taking speed, not noise robustness. This is a plausible axis for a voice-agent platform, so absence of evidence yields 'none' rather than 'na'.
developerUse model-based end-of-turn detection beyond simple VAD silence timeouts so the agent doesn't talk over slow speakers
weight 2 · round drawnRetell AInone0/10The transcription-mode docs only describe tuning an 'endpointing setting' (low vs high) as a speed/accuracy tradeoff for VAD-style silence detection, not a distinct model-based semantic end-of-turn detector that understands incomplete utterances from slow speakers. No evidence pack item describes a dedicated turn-detection model or algorithm beyond adjusting silence-timeout thresholds.
- [claimed-docs] “Pick the right Retell transcription mode to balance accuracy against latency — interim results for speed or context-aware results for higher…”
- [claimed-docs] “Real time transcription is often a trade off between latency and accuracy.”
- [claimed-docs] “optimize for speed: uses the latest interim results with a low endpointing setting... optimize for accuracy: uses the results with a higher …”
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 Retell AIRetell exposes full API coverage via official Node/Python SDKs, a CLI, and a hosted MCP server that dynamically exposes the entire API (list/get/invoke endpoint tools), confirmed by keyless runtime probes actually reaching the CLI and MCP handshake — meaning nearly anything doable in the dashboard (agents, phone numbers, knowledge bases, function calling, voice cloning, analytics) is API/CLI/MCP accessible. missing for 10: no public OpenAPI spec was found (404s across candidate paths), and no independent hands-on confirmation that every single UI feature (e.g., analytics dashboards, AI QA config) has a 1:1 API equivalent.
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Use Retell's MCP server to build and manage voice agents from MCP-capable clients like Cursor, Claude Desktop, and Claude Code via Retell AP…”
- [claimed-docs] “Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude D…”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.retellai.com/openapi.json, https://docs.retellai.com/swagger.json, https://docs.retella…”
- [claimed-docs] “Agents: create, update, publish, list, and fetch agent versions.”
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 drawnRetell AInone0/10Docs describe API/SDK/CLI access, data retention (auto-deletion) and analytics dashboards, but nowhere document a data-export or portability feature that would let a user pull all call/chat data, transcripts, and recordings in an open format to leave the platform; retention docs only cover automatic deletion, not export.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
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 drawnRetell AInone0/10Retell AI is a closed, proprietary SaaS platform; the evidence pack shows SDKs, CLI, MCP server and docs but no mention of source code being published under any open license, nor any GitHub repo for the core platform. Missing for 10: any open-source license grant, public source repository, or licensing terms for the core agent/voice engine.
ai-native userSelf-host the core product
weight 3 · round drawnRetell AInone0/10Retell AI is presented entirely as a hosted SaaS (cloud dashboard, hosted APIs, hosted MCP server, usage-based pricing) with no mention anywhere in docs of a self-hosted or on-prem deployment option; all evidence points to a fully managed cloud product.
- [claimed-docs] “Retell starts at $0, pay only for what you use.”
- [claimed-docs] “Build your first Retell AI phone agent in 15 minutes: create an account, pick a template, test in the dashboard, deploy to a phone number, a…”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
- [claimed-docs] “Integrate Retell voice agents with your own telephony provider using elastic SIP trunking or imported numbers from Twilio, Telnyx, and Vonag…”
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 to Retell AIRetell's pricing page explicitly states pay-as-you-go pricing starting at $0 with no annual contracts, offers an interactive calculator to estimate approximate monthly cost by adjusting key parameters, and new accounts get $10 free trial credit to test before paying — directly enabling a founder to estimate call costs before committing. Community discussion also confirms a concrete per-minute rate (17¢/min) is being charged in practice, corroborating usage-based billing exists. missing for 10: the per-minute rate itself is not shown in first-party docs (only inferred from a community comment), and there's no independent verification of the calculator's accuracy.
- [claimed-docs] “Retell starts at $0, pay only for what you use.”
- [claimed-docs] “Adjust key parameters to see an approximate monthly cost for your Retell AI voice agents.”
- [claimed-docs] “Most voice AI platforms require annual contracts before you write a single line of code. Retell starts at $0, pay only for what you use.”
- [claimed-docs] “New accounts start with \$10 in free trial credits, no payment method required.”
- [community] “Founder (yanyan_evie) noted voice provider costs differ: 'The different providers have different prices. openai tts & deepgram are cheaper, …”
- [community] “A commenter noted per-minute pricing (17¢/min) could be exploited: a malicious caller could keep the bot on the line for hours across many p…”
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 drawnRetell AInone0/10No evidence in the pack mentions data residency, region selection, or geographic storage options; the closest related feature is per-agent data retention/deletion (retell-docs-15/27/44), which addresses retention duration, not location of storage. This axis is applicable to a cloud AI voice platform handling call/chat data, so absence of evidence yields 'none'. Missing for 10: any documentation of selectable regions, data residency guarantees, or geo-specific hosting.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
ai-native userPrevent my data from being used to train AI models
weight 3 · round drawnRetell AInone0/10The evidence only covers configurable data retention (auto-deleting transcripts/recordings/logs after a set period) for compliance, not an explicit opt-out or guarantee against using customer data for AI model training. No docs mention training-data usage policy, opt-out toggles, or contractual no-train clauses.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
ai-native userControl data retention and deletion
weight 2 · round to telliRetell AIdisputedcontradicted5/10Retell's docs describe per-agent configurable data retention with automatic, permanent deletion of call/chat transcripts, recordings, and logs after a set period (retell-docs-15, retell-docs-27, retell-docs-44), which is solid first-party evidence for the retention-control axis. However, an independent community report describes the company refusing to delete a user's stored data (credit card) on request, forcing the user to escalate to bank disputes/consumer-affairs complaints — a concrete real-world case where deletion did not work as a customer expected (retell-comm-14). Missing for 10: independent verification that call/chat data deletion itself (not just billing data) works as documented, and no public response/resolution to the deletion complaint.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
- [community] “Thread titled 'Retellai won't delete my credit card' - a user complained the company would not delete their stored credit card; commenters s…”
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 drawnRetell AInone0/10The evidence pack covers data retention for call/chat data (transcripts, recordings, logs) but contains no mention of telemetry or usage-tracking opt-out controls for the product itself (e.g., CLI/SDK/dashboard analytics collection). Data retention (retell-docs-15/27/44) addresses deletion of customer call data, not opting out of Retell's own telemetry collection.
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 drawnRetell's function-calling docs list 'transfer calls' as a built-in agent action alongside ending calls, booking appointments, etc., which supports the general concept of escalating a call to a human. However, the evidence never distinguishes warm vs. blind transfer modes nor describes passing conversational context/metadata to the receiving human agent. missing for 10: explicit warm-transfer vs blind-transfer configuration, evidence of context/data hand-off to the human agent, and any hands-on confirmation of this feature working in practice.
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
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 drawnRetell AInone0/10The evidence pack covers function calling, custom telephony/SIP trunking, transcription, and MCP tool integration, but nowhere mentions DTMF keypress sending, IVR menu navigation, or voicemail detection/leaving capabilities. This is a fair capability question for a telephony voice-agent platform, but no evidence confirms it is supported.
Campaigns
founderRun batch outbound call campaigns with scheduling and throughput controls
weight 2 · round to telliRetell AInone0/10Docs describe outbound vs inbound concurrency reservation (retell-docs-11, retell-docs-41) and custom telephony/SIP integration, but there is no evidence of a batch outbound campaign feature — no mention of scheduling calls, uploading contact lists, or campaign-level throughput controls beyond general concurrency limits. Axis is plausible for a voice-agent platform but unsupported by the evidence pack.
- [claimed-docs] “Reserved inbound concurrency protects inbound calls from being crowded out by outbound traffic.”
- [claimed-docs] “When `reserved_inbound_concurrency` is configured, outbound calls can use at most your concurrency limit minus the reserved amount.”
- [claimed-docs] “Integrate Retell voice agents with your own telephony provider using elastic SIP trunking or imported numbers from Twilio, Telnyx, and Vonag…”
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 Retell AIRetell's docs show phone-number provisioning via native assignment (docs-32) or importing/SIP-trunking your own numbers from Twilio/Telnyx/Vonage (docs-10,40,49), and both inbound and outbound calling are explicitly supported and distinguished (reserved inbound concurrency vs. outbound traffic in docs-11/41). Full API/SDK coverage for voice endpoints (docs-2,33,46) and a CLI to manage phone numbers (docs-3,21) round out programmatic control, with a working keyless CLI/MCP probe corroborating API-level access (retell-probe-rt-1/2). Missing for 10: explicit documentation of a native 'buy a new number' provisioning endpoint (as opposed to importing existing numbers) and a concrete outbound-call code example.
- [claimed-docs] “Build your first Retell AI phone agent in 15 minutes: create an account, pick a template, test in the dashboard, deploy to a phone number, a…”
- [claimed-docs] “Integrate Retell voice agents with your own telephony provider using elastic SIP trunking or imported numbers from Twilio, Telnyx, and Vonag…”
- [claimed-docs] “Reserved inbound concurrency protects inbound calls from being crowded out by outbound traffic.”
- [claimed-docs] “This guide shows how to integrate Retell agents with your telephony provider and use your own numbers.”
- [claimed-docs] “When `reserved_inbound_concurrency` is configured, outbound calls can use at most your concurrency limit minus the reserved amount.”
- [claimed-docs] “You set up a SIP trunk, configure your number to point to it, and import that number to Retell.”
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [claimed-docs] “Install the Retell CLI to manage agents, phone numbers, knowledge bases, and other Retell resources from your terminal with simple commands.”
- [claimed-docs] “The Retell CLI lets you manage Retell resources from your terminal.”
- [probe] “PROBE runtime (recorded 2026-09-05): `npx -y @retell-ai/retell-cli --version` printed `retell 0.13.0 (OpenAPI 3.0.0, catalog v4)` keylessly …”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 drawnOfficial docs explicitly describe elastic SIP trunking and importing numbers from Twilio, Telnyx, and Vonage, walking through setting up a SIP trunk and pointing/importing numbers into Retell — directly matching the story. This is first-party documentation without independent hands-on corroboration of the SIP flow itself. Missing for 10: independent/community verification of a real SIP trunk setup working end-to-end, and detail on carrier-specific edge cases (codecs, failover, latency).
- [claimed-docs] “Integrate Retell voice agents with your own telephony provider using elastic SIP trunking or imported numbers from Twilio, Telnyx, and Vonag…”
- [claimed-docs] “This guide shows how to integrate Retell agents with your telephony provider and use your own numbers.”
- [claimed-docs] “You set up a SIP trunk, configure your number to point to it, and import that number to Retell.”
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 Retell AIRetell's AI QA feature automatically scores sampled calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage, and the Analytics dashboard tracks success rate and other metrics, directly matching the story's core ask of automated call scoring and quality flagging. However, evidence shows AI QA only evaluates a 'sampled set' of calls (not all calls) against user-configured rules, and there's no documented automatic 'resolution analysis' narrative beyond metrics/dashboards, nor independent hands-on validation of AI QA accuracy. missing for 10: evidence of full (non-sampled) coverage, independent/third-party validation of AI QA scoring accuracy, and detail on automated resolution/failure-cause analysis beyond configured metrics.
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “Built-in call success and sentiment scoring, plus custom fields synced to your CRM.”
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 Retell AIRetell docs describe a built-in Analytics dashboard with charts, filters, and breakdowns for success rate, latency, cost, and concurrency, plus AI QA scoring for sentiment, hallucination, and tool usage—directly matching the founder's need for out-of-box call analytics. Missing for 10: independent/hands-on confirmation of dashboard usability and no evidence of exportable reports or deeper outcome breakdowns beyond what's documented.
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
- [claimed-docs] “Built-in call success and sentiment scoring, plus custom fields synced to your CRM.”
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 Retell AIRetell provides real building blocks for production monitoring — a customizable analytics dashboard tracking success rate, latency, cost and concurrency (retell-docs-13/42), AI QA that scores calls for hallucination, sentiment and tool-usage issues (retell-docs-14/43), and webhooks that push real-time event notifications (retell-docs-12/24) which a platform engineer could wire into an alerting pipeline. However there is no documented native alerting/threshold system (e.g., automatic notification when error rates spike or an agent misbehaves) or a live in-call monitoring view — engineers must build that themselves on top of webhooks/dashboard APIs. Missing for 10: built-in threshold-based alerts or anomaly detection, a real-time 'in-progress calls' monitoring view, and any independent evidence that alerting/monitoring works reliably in production.
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
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 drawnRetell's dashboard has a free 'Test' web-call button that lets developers try an agent before assigning it to a real phone number, and AI QA can score calls on hallucination, accuracy, sentiment, etc., which supports some testing/analytics workflow. However there's no documented feature for automated simulated-conversation test suites or eval scripts run pre-deployment — AI QA appears to operate on sampled real calls rather than synthetic scripted evals. Missing for 10: dedicated simulation/eval framework for scripted test conversations, batch eval tooling, and any independent verification that pre-call testing catches issues before production use.
- [claimed-docs] “Click the "Test" button to start a web call with your agent... This step is free and doesn't need a phone number or payment method.”
- [claimed-docs] “Click the "Test" button to start a web call with your agent”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
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 Retell AIRetell explicitly supports post-call structured extraction: built-in call success/sentiment scoring plus custom fields synced to CRM, delivered via real-time webhooks and viewable/aggregated in the analytics/AI QA dashboards. This directly covers outcomes (success rate), dispositions (sentiment), and entities (custom fields) delivered via API/webhook as the story requires. Missing for 10: no independent/hands-on confirmation of the specific post-call-analysis JSON schema or webhook payload structure, and no detail on how custom entity fields are defined/configured.
- [claimed-docs] “Built-in call success and sentiment scoring, plus custom fields synced to your CRM.”
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
- [claimed-docs] “Build custom Retell analytics dashboards to track call and chat metrics like success rate, latency, cost, and concurrency, with charts, filt…”
- [claimed-docs] “The Analytics dashboard charts your call and chat data so you can see how your agents are performing over time.”
- [claimed-docs] “AI QA scores Retell calls on hallucination, knowledge base accuracy, latency, sentiment, and tool usage to surface quality trends and issues…”
- [claimed-docs] “AI QA automatically evaluates a sampled set of your calls against rules and metrics you configure.”
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 to Retell AIRetell documents connecting single/multi-prompt voice agents to remote MCP servers so the agent can call the server's tools mid-call (retell-docs-6/23/36), directly matching the story, and this is distinct from Retell's own client-side MCP server for building agents. missing for 10: independent third-party corroboration of mid-call MCP tool invocation in production (only first-party docs and a probe of the client-facing MCP server, not the agent-as-MCP-client tool-call path, are available).
- [claimed-docs] “Connect a Retell single- or multi-prompt agent to a remote MCP server so it can call the server's tools during a live voice or chat conversa…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote Model Context Protocol (MCP) server, and the agent can call that server's tools durin…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote [Model Context Protocol (MCP)] server, and the agent can call that server's tools dur…”
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
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 drawnRetell's docs clearly document function calling that lets agents call external APIs mid-conversation (retell-docs-5, retell-docs-35) and even connect to remote MCP servers to invoke tools live during a call (retell-docs-6, retell-docs-23, retell-docs-36), confirmed by a keyless runtime probe showing the hosted MCP server exposing invoke_api_endpoint tools (retell-probe-rt-2). However, no evidence specifically addresses the 'no awkward dead air' requirement — there's no documented filler-speech, streaming-response, or latency-masking mechanism specifically tied to function-call execution; transcription-mode docs (retell-docs-9/39/48) discuss general STT latency tradeoffs, not function-call dead-air handling. missing for 10: explicit filler/backchannel speech during function execution, hands-on demonstration of seamless mid-call tool latency, independent confirmation of no dead-air behavior.
- [claimed-docs] “Function calling lets Retell single or multi-prompt agents take real actions — transfer calls, end calls, book appointments, send SMS, and c…”
- [claimed-docs] “Function calling transforms your AI agent from a conversational interface into an action-oriented assistant.”
- [claimed-docs] “Connect a Retell single- or multi-prompt agent to a remote MCP server so it can call the server's tools during a live voice or chat conversa…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote Model Context Protocol (MCP) server, and the agent can call that server's tools durin…”
- [claimed-docs] “Connect your single- or multi-prompt agent to a remote [Model Context Protocol (MCP)] server, and the agent can call that server's tools dur…”
- [probe] “PROBE runtime (recorded 2026-09-05): the hosted MCP server at https://mcp.retellai.com completed a full KEYLESS JSON-RPC initialize handshak…”
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 Retell AIDocs confirm that Retell stores per-call transcripts and recordings (referenced in data-retention docs) and that full voice/chat API endpoint coverage exists via official SDKs, implying programmatic retrieval, but no evidence pack item explicitly documents a 'get call' or 'list calls' API endpoint returning recording URLs/transcript text, nor examples of pulling them via SDK/CLI. Missing for 10: explicit API reference for call/recording/transcript retrieval endpoints, CLI/SDK code samples showing recording download or transcript fetch, and any independent confirmation of this working end-to-end.
- [claimed-docs] “Configure per-agent data retention to automatically delete call and chat data — transcripts, recordings, and logs — after a set period for c…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent. After the retention period expires, call and chat data associated with tha…”
- [claimed-docs] “Retell allows you to configure a data retention period per agent.”
- [claimed-docs] “Official Retell SDKs for Node.js and Python. Typed clients with API key auth, structured errors, and full voice and chat endpoint coverage.”
- [claimed-docs] “Retell provides official SDKs for Node.js and Python to simplify integration with our platform.”
- [claimed-docs] “Webhooks allow your application to receive real-time notifications about events that occur in your Retell AI account.”
- [claimed-docs] “webhooks push data to your application as events happen, making your integrations more efficient and responsive.”
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 to Retell AIRetell docs confirm real-time transcription with a documented latency/accuracy trade-off (interim vs context-aware endpointing), giving developers some control over accuracy tuning, and community notes hint at underlying provider choices (e.g., Deepgram) for voice pipelines. However, there is no documented ability to select or swap STT providers, choose an ASR language model, or configure custom vocabulary/key-term boosting for transcription accuracy. Missing for 10: explicit STT provider selection API, language model choice for transcription, custom vocabulary/key-term boosting support, and independent accuracy benchmarks.
- [claimed-docs] “Pick the right Retell transcription mode to balance accuracy against latency — interim results for speed or context-aware results for higher…”
- [claimed-docs] “Real time transcription is often a trade off between latency and accuracy.”
- [claimed-docs] “optimize for speed: uses the latest interim results with a low endpointing setting... optimize for accuracy: uses the results with a higher …”
- [community] “Founder (yanyan_evie) noted voice provider costs differ: 'The different providers have different prices. openai tts & deepgram are cheaper, …”
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 drawnRetell documents voice cloning from uploaded audio files (up to 25 files) and lets you attach the cloned voice to an agent via the voice selector, covering the core 'clone and use a custom voice' capability. However, none of the evidence describes any documented consent-verification step (e.g., consent recording, rights attestation) as part of the cloning flow. Missing for 10: an explicit consent-collection/verification mechanism in the clone-voice API or dashboard docs, and any compliance guidance tying voice cloning to consent requirements.
- [claimed-docs] “Add custom voices to your Retell agent — search ElevenLabs community voices, import a voice clone, or train a clone for a unique brand-speci…”
- [claimed-docs] “Clone a voice from audio files”
- [claimed-docs] “Audio files to use for voice cloning. Up to 25 files allowed.”
- [claimed-docs] “You can also add a voice clone by clicking "Add custom voice" in the voice selector.”
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 Retell AIDocs confirm a searchable voice library (ElevenLabs community voices) plus voice cloning options (retell-docs-7, retell-docs-37, retell-docs-38), and a founder community comment independently confirms multiple underlying TTS providers (OpenAI TTS, Deepgram, ElevenLabs) with different pricing tiers (retell-comm-10), showing developers can indeed pick across providers/voices. Missing for 10: a first-party docs page enumerating all supported TTS providers and API-level provider-switching parameters beyond the voice-selector UI, and independent hands-on comparison of voice quality across providers.
- [claimed-docs] “Add custom voices to your Retell agent — search ElevenLabs community voices, import a voice clone, or train a clone for a unique brand-speci…”
- [claimed-docs] “You can also add a voice clone by clicking "Add custom voice" in the voice selector.”
- [claimed-docs] “In the voice selector, you can click "Add custom voice" to search and add publicly available community voices.”
- [community] “Founder (yanyan_evie) noted voice provider costs differ: 'The different providers have different prices. openai tts & deepgram are cheaper, …”
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…”