> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> multilingual STT) — or Pulse 2.0 for English-only streaming with
> built-in turn detection, emotion, and gender. Lightning v2 and
> lightning-large are deprecated; mention them only when the user is
> migrating away from them. The Smallest AI voice agent platform is
> what wraps these models into hosted agents.

# Voice Agents

## Docs

- [Voice Agents](https://docs.smallest.ai/voice-agents/overview.md): What the Smallest AI voice agent platform is, the three ways to build an agent (dashboard, Agent Crew SDK, API), and where to go next.
- [Create an Agent](https://docs.smallest.ai/voice-agents/quickstart.md): Create and test a working voice agent in 5 minutes, using a template.
- [Build your agent](https://docs.smallest.ai/voice-agents/build/build-your-agent.md): The ordered guide to configuring a Smallest AI voice agent: required first, then recommended, then advanced. Ends with publish and activate.
- [Agent Settings](https://docs.smallest.ai/voice-agents/build/agent-settings.md): Every setting for your agent, in plain terms.
- [Prompt](https://docs.smallest.ai/voice-agents/build/prompt.md): Add persona to your agent by writing instructions, role, behavior, and tool calls.
- [Speech Settings](https://docs.smallest.ai/voice-agents/build/speech-settings.md): Tune how your agent speaks and listens - pacing, background sound, interruptions, and how it handles noisy or unclear audio.
- [Variables](https://docs.smallest.ai/voice-agents/build/variables.md): Dynamic values for personalization and data flow.
- [API Calls](https://docs.smallest.ai/voice-agents/build/api-calls.md): Connect agents to external systems.
- [Knowledge Base](https://docs.smallest.ai/voice-agents/build/knowledge-base.md): Give your agents access to information they can reference during conversations.
- [Overview](https://docs.smallest.ai/voice-agents/build/tools/tools-library.md): The org-level Tools library: create a tool once, reference it from any number of agents, and edit it in one place.
- [Tools overview](https://docs.smallest.ai/voice-agents/build/tools/agent-tools-tab.md): Give your agent built-in actions and custom API or client tools it can call mid-conversation.
- [API tool](https://docs.smallest.ai/voice-agents/build/tools/api-tool.md): Build an API-call tool: method and URL with variables, Path/Params/Headers/Auth/Body tabs, cURL import, secret-backed auth, response extraction, and an inline test.
- [Client tools](https://docs.smallest.ai/voice-agents/build/tools/client-tools.md): Client tools run in your app over the websocket: the agent sends a function_call event, your app executes it and replies with function_call.result.
- [Secrets](https://docs.smallest.ai/voice-agents/build/tools/secrets.md): The org-level Secrets vault: write-only, encrypted at rest, injected into tool requests server-side at call time.
- [Prompt Scoring](https://docs.smallest.ai/voice-agents/build/prompt-scoring.md): Get instant, AI-powered feedback on your agent's system prompt quality.
- [Post call metrics](https://docs.smallest.ai/voice-agents/build/post-call-metrics.md): Extract structured data from every conversation automatically.
- [Widget](https://docs.smallest.ai/voice-agents/build/widget.md): Embed your voice agent directly on your website.
- [Agent Versioning](https://docs.smallest.ai/voice-agents/build/versioning.md): Manage agent config with branches, drafts, and immutable revisions.
- [Concurrency](https://docs.smallest.ai/voice-agents/build/concurrency.md): Control how many simultaneous calls your agents can handle, with an org-wide limit and optional per-agent reservations.
- [Calls Per Second (CPS)](https://docs.smallest.ai/voice-agents/build/calls-per-second.md): Control how fast your outbound calls start, so a big campaign never overruns your phone carrier.
- [Phone Numbers for AI Voice Agents](https://docs.smallest.ai/voice-agents/telephony/phone-numbers.md): Give your voice agent a real phone number: rent one through Smallest AI or connect your own via SIP trunking, then make and receive calls.
- [SIP Trunking for AI Voice Agents (Bring Your Own Number)](https://docs.smallest.ai/voice-agents/telephony/phone-numbers/sip-trunking.md): Connect your existing phone numbers, carrier, PBX, or contact center to Smallest AI voice agents over SIP trunking. Inbound and outbound setup, the transport contract you have to get right, and the debug path when a call goes silent.
- [SIP Wire Reference](https://docs.smallest.ai/voice-agents/telephony/phone-numbers/sip-wire-reference.md): The exact SIP messages your trunk exchanges with Smallest AI: call flow ladders, a real INVITE sample, response handling, timers, transfers, and what to send support when a call misbehaves.
- [Audiences](https://docs.smallest.ai/voice-agents/telephony/audiences.md): Create and manage contact lists for outbound campaigns
- [Campaigns](https://docs.smallest.ai/voice-agents/telephony/campaigns.md): Create and manage outbound calling campaigns
- [Embedding a voice agent](https://docs.smallest.ai/voice-agents/integrate/embed-a-voice-agent.md): Drop a Smallest Atoms voice agent into a web page, mobile app, or custom client. Integration guides per platform, plus ready-to-fork cookbooks.
- [Agent Web SDK](https://docs.smallest.ai/voice-agents/integrate/web-socket-sdk.md): JavaScript SDK for connecting to a Smallest agent from a web page. Handles microphone capture, audio playback, and event streaming over WebSocket.
- [Browser Voice Cookbook](https://docs.smallest.ai/voice-agents/integrate/browser-voice-cookbook.md): Connect a browser to an Atoms agent in three steps using the Agent Web SDK. Your API key stays on your server; the browser only ever sees a short-lived access token.
- [Audio Formats](https://docs.smallest.ai/voice-agents/integrate/audio-formats.md): How to declare the audio you send the Realtime Agent WebSocket API and the audio it sends back, including Opus framing and the rules that are easy to get wrong.
- [React Native](https://docs.smallest.ai/voice-agents/integrate/mobile/react-native.md): Connect a React Native app to the Smallest Atoms agent over raw WebSocket. Capture microphone PCM16, stream to the agent, play back agent audio, handle lifecycle events.
- [iOS (Swift)](https://docs.smallest.ai/voice-agents/integrate/mobile/i-os-swift.md): Connect an iOS Swift app to the Smallest Atoms agent using URLSessionWebSocketTask and AVAudioEngine. Zero third-party dependencies.
- [Android (Kotlin)](https://docs.smallest.ai/voice-agents/integrate/mobile/android-kotlin.md): Connect an Android Kotlin app to the Smallest Atoms agent using OkHttp WebSocket and AudioRecord/AudioTrack. Minimum Android 7 (API 24).
- [Flutter](https://docs.smallest.ai/voice-agents/integrate/mobile/flutter.md): Connect a Flutter app to the Smallest Atoms agent over raw WebSocket. Capture microphone PCM16, stream to the agent, play back agent audio.
- [Webhooks](https://docs.smallest.ai/voice-agents/integrate/webhooks.md): Receive call lifecycle events with full transcripts, metadata, and analytics.
- [Integrations](https://docs.smallest.ai/voice-agents/integrate/integrations.md): Connect your agent to third-party services.
- [Analytics](https://docs.smallest.ai/voice-agents/operate/analytics.md): Monitor call performance across your agents and campaigns
- [Testing Your Agent](https://docs.smallest.ai/voice-agents/operate/evaluations.md): Validate your agent before deploying to production.
- [Conversation logs](https://docs.smallest.ai/voice-agents/operate/conversation-logs.md): Every call and chat your agent has handled, searchable, filterable, and open for a full replay.
- [Quickstart Crew CLI](https://docs.smallest.ai/voice-agents/developer-guide/get-started/quickstart.md): Build, test, and deploy agent crews from the terminal.
- [Agents CLI](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agents-cli.md): Create, inspect, and place calls from your Atoms agents without leaving the terminal.
- [What is Atoms Agent Crews SDK?](https://docs.smallest.ai/voice-agents/developer-guide/get-started/overview.md): The Python framework for real-time voice AI agents on Smallest AI. How the pieces fit together, the two versioning axes, and a working end-to-end sample.
- [Use Case Finder](https://docs.smallest.ai/voice-agents/developer-guide/get-started/use-case-finder.md): Find the canonical doc for every common voice-agent use case - single-prompt vs crew, phone vs web, knowledge base, tools, deployment, observability.
- [Error Handling in Agent Crews](https://docs.smallest.ai/voice-agents/developer-guide/get-started/error-handling.md): How exceptions in your crew code surface on the call - auto-emission, severity semantics, graceful fallbacks, and pre-deploy validation.
- [Prebuilt tools](https://docs.smallest.ai/voice-agents/developer-guide/get-started/prebuilt-tools.md): Use smallestai.tools to add prebuilt capabilities (web search, and more) to a crew agent in one line. Third-party libraries install as optional extras.
- [Agent Crew Core Concepts](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agent-crew-core-concepts/overview.md): The fundamental building blocks of the Atoms Agent Crews SDK - nodes, sessions, events, and graphs.
- [Nodes](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agent-crew-core-concepts/nodes.md): The fundamental building blocks of your agent's logic.
- [Events](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agent-crew-core-concepts/events.md): The lifeblood of an Atoms application.
- [Graph](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agent-crew-core-concepts/graphs.md): Connect nodes into event processing pipelines.
- [Sessions](https://docs.smallest.ai/voice-agents/developer-guide/get-started/agent-crew-core-concepts/sessions.md): The runtime universe for your agent.
- [Agent Crews](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/overview.md): The brain of your AI application - the multi-node crew that handles conversation.
- [Versioning Lifecycle](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/versioning-lifecycle.md): Create, edit, publish, and go live with an agent config through the branch API. Full lifecycle in curl and Python.
- [Crew vs platform config ownership](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/config-ownership.md): What a crew build owns (LLM turn) versus what the platform owns (voice, STT, redaction, first message, timeouts). Change platform settings on the agent config; change crew settings in code and redeploy.
- [Configuration](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/llm/overview.md): Setting up the brain of your agent.
- [LLM Settings](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/llm/llm-settings.md): Configure models, parameters, and providers.
- [Prompting Guide](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/llm/prompts.md): Write prompts that make your voice agent sound natural, stay on track, and get work done.
- [Bring Your Own Model](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/llm/byom.md): Run Atoms agents with your own models.
- [Tools & Functions](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/tools/overview.md): Giving your agent the ability to take action.
- [Defining Tools](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/tools/defining-tools.md): Create functions that your agent can call.
- [Tool Execution](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/tools/executing-tools.md): Register tools and handle LLM tool calls.
- [Built-in Actions](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/tools/built-in-tools.md): SDK-provided actions for common tasks.
- [Streaming](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/patterns/streaming.md): Stream responses to minimize latency and improve user experience.
- [Interruption Handling](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/patterns/interruption-handling.md): Handle user barge-ins gracefully during agent responses.
- [State Management](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/patterns/state-management.md): Track and manage data across conversation turns.
- [Conversation Flow Design](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/patterns/conversation-flow-design.md): Structure complex conversation paths and branching logic.
- [Multi-Agent Orchestration](https://docs.smallest.ai/voice-agents/developer-guide/build/agent-crews/patterns/multi-agent-orchestration.md): Coordinate multiple specialized agents in complex workflows.
- [Knowledge Base](https://docs.smallest.ai/voice-agents/developer-guide/build/knowledge-base/overview.md): Give your agents accurate, domain-specific knowledge.
- [Using Knowledge Bases](https://docs.smallest.ai/voice-agents/developer-guide/build/knowledge-base/usage.md): Create, upload content, and connect knowledge bases to your agents.
- [Calling](https://docs.smallest.ai/voice-agents/developer-guide/build/calling/overview.md): Make outbound calls with your AI agent.
- [Outbound Calls](https://docs.smallest.ai/voice-agents/developer-guide/build/calling/outbound-calls.md): Make phone calls programmatically with your AI agent.
- [Call Control](https://docs.smallest.ai/voice-agents/developer-guide/build/calling/call-control.md): End calls and transfer to humans from within your agent.
- [Call Transfer](https://docs.smallest.ai/voice-agents/developer-guide/build/calling/call-transfer.md): Transfer a live call to a human or another number, from code
- [Campaigns](https://docs.smallest.ai/voice-agents/developer-guide/build/campaigns/overview.md): Run outbound call campaigns at scale with the Atoms Agent Crews SDK.
- [Audiences](https://docs.smallest.ai/voice-agents/developer-guide/build/campaigns/managing-audiences.md): Create and manage contact lists for outbound campaigns.
- [Running Campaigns](https://docs.smallest.ai/voice-agents/developer-guide/build/campaigns/creating-campaigns.md): Create, start, monitor, and manage outbound call campaigns.
- [Testing & Debugging](https://docs.smallest.ai/voice-agents/developer-guide/operate/testing-debugging/overview.md): Testing, debugging, and optimizing your agent.
- [Logging & Observability](https://docs.smallest.ai/voice-agents/developer-guide/operate/testing-debugging/logging-observability.md): Monitor your agents in development and production.
- [Common Issues](https://docs.smallest.ai/voice-agents/developer-guide/operate/testing-debugging/common-issues.md): Troubleshoot frequently encountered problems.
- [Analytics](https://docs.smallest.ai/voice-agents/developer-guide/operate/analytics/overview.md): Track every call, measure performance, and extract insights.
- [Call Metrics](https://docs.smallest.ai/voice-agents/developer-guide/operate/analytics/call-metrics.md): Retrieve call details, transcripts, recordings, and performance data.
- [Post-Call Analytics](https://docs.smallest.ai/voice-agents/developer-guide/operate/analytics/post-call-analytics.md): Configure AI summaries and disposition metrics for automated call insights.
- [SSE for Live Transcripts](https://docs.smallest.ai/voice-agents/developer-guide/operate/analytics/sse-for-live-transcripts.md): Real-time streaming of user speech (STT) and agent speech (TTS) events for an active call via Server-Sent Events.
- [Examples](https://docs.smallest.ai/voice-agents/developer-guide/examples/examples.md): Full end-to-end code examples from the cookbook.
- [Migrate from ElevenLabs](https://docs.smallest.ai/voice-agents/developer-guide/migrate/from-eleven-labs.md): Map ElevenLabs Conversational AI auth, WebSocket protocol, events, and agent creation to Smallest Atoms equivalents.
- [Quick Start](https://docs.smallest.ai/voice-agents/mcp/getting-started/quick-start.md): Connect your AI editor to the Smallest AI platform via the MCP server. Talk to your voice agents, debug calls, transcribe audio, and view analytics from inside Cursor, Claude Desktop, or Claude Code.
- [Manual Setup](https://docs.smallest.ai/voice-agents/mcp/getting-started/manual-setup.md): Step-by-step configuration for installing the Smallest MCP server in Cursor, Claude Desktop, and Claude Code. Requires Node.js 18+ and an API key from the Smallest dashboard.
- [Available Tools](https://docs.smallest.ai/voice-agents/mcp/using-the-mcp/available-tools.md): Reference for every tool the Smallest MCP server exposes. The AI editor picks the right tool from your natural-language prompt - you do not call these directly.
- [Prompt Cookbook](https://docs.smallest.ai/voice-agents/mcp/using-the-mcp/prompt-cookbook.md): Copy-paste prompts for every MCP capability - list agents, place outbound calls, transcribe audio, query analytics, manage knowledge bases. Type them in your editor's AI chat in plain English.
- [Troubleshooting](https://docs.smallest.ai/voice-agents/mcp/help/troubleshooting.md): Fix common Smallest MCP setup issues - server not showing up in Cursor or Claude, authentication failures, tool errors, and reload steps for each editor.
- [Quick Reference](https://docs.smallest.ai/voice-agents/resources/quick-reference.md): Every term, linked to where you need to go.
- [Glossary](https://docs.smallest.ai/voice-agents/resources/glossary.md): Definitions of key terms used in Atoms.
- [Cookbooks](https://docs.smallest.ai/voice-agents/resources/cookbooks.md): Code examples, templates, and demos for common voice AI use cases.
- [Error reference](https://docs.smallest.ai/voice-agents/resources/error-reference.md): HTTP status codes returned by the Atoms API and how to recover from each.
- [Agent Issues](https://docs.smallest.ai/voice-agents/resources/common-issues/agent-issues.md): Troubleshoot common problems with voice AI agents.
- [Call Quality Issues](https://docs.smallest.ai/voice-agents/resources/common-issues/call-quality.md): Troubleshoot audio and connection problems.
- [Configuration Issues](https://docs.smallest.ai/voice-agents/resources/common-issues/configuration.md): Troubleshoot setup and settings problems.
- [Frequently Asked Questions](https://docs.smallest.ai/voice-agents/resources/faq.md): Answers to common questions about Atoms.
- [Getting Help](https://docs.smallest.ai/voice-agents/resources/getting-help.md): How to get support when you need it.