# OnCore Developer Docs > Documentation for the OnCore voice AI platform: REST API, embedded voice and chat channels, and webhooks. ## Getting Started - [Introduction](https://docs.heysadie.ai/getting-started/introduction): What the OnCore Core API is and what you can build with it. - [Quickstart](https://docs.heysadie.ai/getting-started/quickstart): Go from an empty account to your assistant answering its first phone call in about 10 minutes. - [Authentication](https://docs.heysadie.ai/getting-started/authentication): How API keys work, where to get them, and the exact header format. - [Errors](https://docs.heysadie.ai/getting-started/errors): The error envelope, status codes, and error codes the Core API returns. ## Guides - [Assistants](https://docs.heysadie.ai/guides/assistants): The full assistant lifecycle — create, configure voice and behavior, attach knowledge and tasks, wire up webhooks, and enable SMS. - [Prompts](https://docs.heysadie.ai/guides/prompts): Manage reusable system prompts, understand global vs tenant prompts, and link them to assistants. - [Tools](https://docs.heysadie.ai/guides/tools): Define function-calling tools that let your assistant call your backend during a call. - [Dynamic transfer](https://docs.heysadie.ai/guides/dynamic-transfer): Let callers be transferred by name, with the destination resolved at call time by your own directory server. - [Knowledge base](https://docs.heysadie.ai/guides/knowledge-base): Upload plain-text documents and attach them to assistants so they can answer from your content. - [Task groups](https://docs.heysadie.ai/guides/taskgroups): Build ordered task flows, link them to assistants, and override task instructions per assistant. - [Phone numbers](https://docs.heysadie.ai/guides/phone-numbers): Search available numbers, purchase one for your tenant, configure failover, and release numbers you no longer need. - [Calls](https://docs.heysadie.ai/guides/calls): Read call activity — filtered lists, statuses, per-assistant summaries, bulk export, and full single-call payloads. - [Conversations](https://docs.heysadie.ai/guides/conversations): Read messaging activity across web chat, SMS, and WhatsApp — filtered lists, statuses, summaries, and export. - [Capture forms](https://docs.heysadie.ai/guides/capture-forms): Define structured forms your assistant fills in during a conversation and delivers to email or SMS recipients. - [Custom instructions](https://docs.heysadie.ai/guides/custom-instructions): Add up to six short, titled behavior tweaks per assistant without editing the main prompt. ## Features - [Voice assistants](https://docs.heysadie.ai/features/voice-assistants): AI assistants that answer your calls in a voice you choose, follow your business's rules, and guide callers through real tasks. - [Phone numbers & telephony](https://docs.heysadie.ai/features/phone-numbers): OnCore supplies the phone number too — search, purchase, and manage numbers through the API and point each one at an assistant. - [Call transfers](https://docs.heysadie.ai/features/call-transfers): OnCore hands calls to your team — instantly, or with a spoken briefing first — whenever a caller needs a human. - [Multi-language calls](https://docs.heysadie.ai/features/multi-language): OnCore answers callers in their own language — detected automatically on every call, with nothing to set up. - [Call recording & transcripts](https://docs.heysadie.ai/features/call-recording): Every OnCore call is transcribed and summarised automatically — and audio recording is a switch you set per assistant. - [Knowledge base](https://docs.heysadie.ai/features/knowledge-base): Your assistant answers callers from your own documents — upload your content once and use it across assistants. - [Custom tools & integrations](https://docs.heysadie.ai/features/custom-tools): OnCore's assistants call your own systems mid-conversation — looking up bookings, checking orders, and taking real action through your API. - [Capture forms](https://docs.heysadie.ai/features/capture-forms): Collect exactly the details you need from every caller — and get the answers by email or text message. - [In-call SMS](https://docs.heysadie.ai/features/in-call-sms): OnCore texts the caller while they're still on the phone — links, price lists, directions — so they hang up with it in hand. - [Web chat](https://docs.heysadie.ai/features/web-chat): Put the same OnCore assistant that answers your phone on your website as a text chat. - [Browser calling (WebRTC)](https://docs.heysadie.ai/features/browser-calling): A "talk to us" button on your website — visitors speak to your OnCore assistant without dialling a number. - [Reporting & webhooks](https://docs.heysadie.ai/features/reporting-webhooks): OnCore pushes every call's outcome to your systems the moment it ends — and lets you pull full call history any time. - [WhatsApp](https://docs.heysadie.ai/features/whatsapp): Your OnCore assistant answers voice calls placed in WhatsApp — same number, same assistant, on the app your customers already use. ## Channels & Embeds - [Browser voice calls (WebRTC)](https://docs.heysadie.ai/channels/webrtc): Let visitors talk to your OnCore assistant straight from a web page. - [Embedded web chat](https://docs.heysadie.ai/channels/web-chat): Add a text chat with your OnCore assistant to any website. - [SMS & texting](https://docs.heysadie.ai/channels/sms): Enable two-way SMS for an assistant and configure SMS follow-ups on voice calls. - [WhatsApp onboarding (resellers)](https://docs.heysadie.ai/channels/whatsapp-onboarding): Enable WhatsApp calling on a tenant's phone number through Meta's Embedded Signup. ## Webhooks - [Overview](https://docs.heysadie.ai/webhooks/overview): How OnCore delivers webhooks, and how to verify each kind. - [Assistant request](https://docs.heysadie.ai/webhooks/assistant-request): The webhook OnCore sends to your server when a call starts. - [End-of-call report](https://docs.heysadie.ai/webhooks/end-of-call-report): The webhook OnCore sends to your server when a call finishes. - [End-of-conversation report](https://docs.heysadie.ai/webhooks/end-of-conversation-report): The webhooks OnCore sends when a messaging conversation starts and ends. - [Tool calls to your server](https://docs.heysadie.ai/webhooks/tool-proxy): The request OnCore sends when the assistant invokes one of your tools mid-call. - [WhatsApp events](https://docs.heysadie.ai/webhooks/whatsapp-events): Signed webhooks for the WhatsApp onboarding lifecycle. ## API Reference - [API Keys](https://docs.heysadie.ai/api-reference/api-keys): Where to view, generate, and rotate your tenant API key and webhook secret. ## Advanced - [Organization-level access](https://docs.heysadie.ai/advanced/org-level-access): Use one organization API key to operate across all your tenants. - [Retention audits](https://docs.heysadie.ai/advanced/retention-audits): File a data-retention audit report after each cleanup run. - [Churn audits](https://docs.heysadie.ai/advanced/churn-audits): File an audit report after cleaning up a churned customer's data. ## What's New - [August 2026](https://docs.heysadie.ai/changelog/2026-08): New Features catalogue, a generated API reference, a rebuilt quickstart, and markdown twins for AI tools.