> ## Documentation Index
> Fetch the complete documentation index at: https://docs.slng.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Features

## List of features

In this table you can see every feature we support.

All of these are available in the [agents API reference](/api-reference/agents/list-agents).

| Category        | Feature                                 | What it does                                                                                                                                                                                                |
| --------------- | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Deployment      | Regions                                 | 14 SLNG Managed regions (US Central, US East, US West, Netherlands, Germany, UK, Brazil, Israel, Japan, Singapore, South Africa, Indonesia, Australia, India) plus 3 LiveKit Cloud regions (EU, US, India). |
| Deployment      | Runtime choice                          | `orchestrator`: LiveKit (default) or Pipecat. Chosen separately from region. Both runtimes use the same model catalog.                                                                                      |
| Deployment      | Region change                           | Change an agent's region for future calls. Calls already in progress stay where they are, and existing agents keep their region until someone changes it.                                                   |
| Models          | Listen / Think / Speak                  | Pick the STT, LLM, and TTS models plus the TTS voice. Options are filtered by the agent's region and language.                                                                                              |
| Models          | Agent model discovery                   | Catalog API with `surface=agent`, `agent_region`, and `language` returns eligible models and voices. Available on regional gateways.                                                                        |
| Models          | Fallbacks and timeouts                  | Ordered backup models for STT, LLM, and TTS if a model fails or times out, plus configurable timeouts.                                                                                                      |
| Models          | Provider options                        | `stt_kwargs`, `llm_kwargs`, `tts_kwargs` for supported provider settings.                                                                                                                                   |
| Models          | BYOK                                    | Use your own provider keys. Entries can be limited by language and region.                                                                                                                                  |
| Execution layer | Noise cancellation                      | Per-agent toggle, on by default.                                                                                                                                                                            |
| Execution layer | TTS caching                             | Per-agent toggle for caching TTS requests, on by default.                                                                                                                                                   |
| Behavior        | System prompt and greeting              | Handlebars-style `{{variable}}` templating in the prompt and greeting.                                                                                                                                      |
| Behavior        | Directional greetings                   | Separate greetings for inbound and outbound calls. Requires at least one phone connection.                                                                                                                  |
| Behavior        | Interruptions                           | Lets the caller talk over the agent.                                                                                                                                                                        |
| Behavior        | Failure audio                           | Plays a short message before ending the call after a technical failure.                                                                                                                                     |
| Behavior        | Idle nudges                             | Recovery prompts when the caller goes silent, with configurable delays and text.                                                                                                                            |
| Variables       | Template inputs                         | Required or optional inputs with defaults (`template_defaults`), overridable per call (`arguments`).                                                                                                        |
| Variables       | Call memory                             | Named fields the model fills in and updates during a conversation.                                                                                                                                          |
| Tools           | Published org tools                     | Attach tools from the org library with model instructions, a pre-action message, and argument or config values.                                                                                             |
| Tools           | MCP servers                             | Attach individual tools from a connected MCP server.                                                                                                                                                        |
| Tools           | Custom Code, built-ins, dynamic prompts | Sandboxed custom code, built-in capabilities, and dynamic prompts.                                                                                                                                          |
| Tools           | Human transfer                          | Transfers the call to a human. Requires an outbound connection.                                                                                                                                             |
| Telephony       | Inbound connections                     | Route phone numbers to an agent (one agent per connection). Twilio guided setup or manual SIP setup.                                                                                                        |
| Telephony       | Outbound connections                    | Outbound calls and transfers, with SIP credentials and caller ID.                                                                                                                                           |
| Telephony       | Region compatibility                    | Connections that don't work with the agent's region are shown as unavailable, with the reason.                                                                                                              |
| Calls           | Call details                            | Status, timestamps, number, template args, rendered prompt, and a session report (transcript, model usage, tool activity).                                                                                  |
| Calls           | Outbound dispatch                       | Place calls to E.164 numbers with template variables and status webhooks.                                                                                                                                   |
| Calls           | Browser embed                           | Web sessions over LiveKit for both runtimes. Room events include `agent_state_changed`, `user_state_changed`, `conversation_item_added`, and `close`.                                                       |
| Testing         | Test agent                              | Browser web session or a real outbound test call, with a live transcript.                                                                                                                                   |
| Observability   | Call history                            | Covers phone calls and web sessions, with filters and CSV export.                                                                                                                                           |
| Observability   | Usage                                   | Recorded usage and costs per project.                                                                                                                                                                       |
| Observability   | Project Vault                           | Shared values and credentials.                                                                                                                                                                              |
| Lifecycle       | Version history                         | Every save creates a version. You can label, compare, and restore versions (a restore creates a new version).                                                                                               |
| Lifecycle       | Export / import                         | Portable JSON config (schema v2 supported) that keeps the region and never includes secrets.                                                                                                                |
| Lifecycle       | Duplicate                               | Copies the config and outbound connection. Call history and the inbound connection are not copied.                                                                                                          |
| Lifecycle       | Templates                               | Start from a template or from scratch.                                                                                                                                                                      |