# Centillion > How to build a Centillion AI agent, give it your knowledge, and put it on your website, WhatsApp, Messenger, Instagram, Slack and email. - [What Centillion is](https://cntillion.com/docs/introduction.md): An AI customer service agent that answers from knowledge you control, on your website, WhatsApp, email, phone and more. See every feature and start free. - [Quickstart](https://cntillion.com/docs/quickstart.md): From a new account to an agent answering on your website - [Build an AI customer support agent](https://cntillion.com/docs/agents/create-an-agent.md): Create a Centillion agent, write its instructions and guardrails, choose a model, and test up to four model settings side by side before you save them. - [Manage an AI agent in plain language](https://cntillion.com/docs/agents/mastermind.md): Mastermind answers from real conversations, audits every agent in your workspace and applies requested edits with Undo. Ask it about your agent. - [Train an AI agent on your website and docs](https://cntillion.com/docs/agents/knowledge.md): Add files, websites, text, Q&A, Notion pages and support tickets to your Centillion agent. Learn the limits per plan and set up weekly auto-resync. - [Training and publishing](https://cntillion.com/docs/agents/training-and-publishing.md): How edits become live answers, and what to check before they do - [Releases, shared tools and workflows](https://cntillion.com/docs/agents/releases-and-workflows.md): Publish versions, reuse resources, design conversation workflows, and measure real outcomes. - [Personalization](https://cntillion.com/docs/agents/personalization.md): Use one agent for inbound and outbound calls with dynamic variables, per-conversation overrides and a caller lookup before the conversation starts. - [Disclosure requirements](https://cntillion.com/docs/agents/disclosure-requirements.md): Tell people they are talking with an AI and that the conversation is recorded, before they start. Where to put the notice in Centillion Labs, with sample wording. - [Procedures](https://cntillion.com/docs/agents/procedures.md): Give your agent reusable tasks with flexible instructions or a fixed sequence of steps. - [Signatures, texts and waiting in workflows](https://cntillion.com/docs/agents/signatures-and-texts.md): Send a DocuSign envelope from a workflow, text or email the signing link, wait for the signature on the call, and take an SSN by keypad without anyone hearing it. - [Test an AI agent with simulated customers](https://cntillion.com/docs/agents/tests.md): Build reusable workspace tests for simulated conversations, individual replies and tool calls, then inspect outcomes before release. - [Agent dashboards, Pulse, topics and sentiment](https://cntillion.com/docs/analytics.md): Monitor agent performance in Pulse and compare conversations, cost, success and customer satisfaction across your workspace in Dashboards. - [AI agent custom tools: call your API](https://cntillion.com/docs/agents/custom-actions.md): Let your Centillion agent call your API, run a function on your website or app, show interactive cards and book Cal.com meetings. Set up a tool. - [System tools: end calls, transfer and more](https://cntillion.com/docs/agents/system-tools.md): Let your Centillion agent end a call, switch language, wait for the customer, transfer to another agent or a person, and detect voicemail. - [AI chatbot lead capture forms and data](https://cntillion.com/docs/agents/collect-data.md): Have your Centillion agent ask for leads, addresses or order details in chat, then send each submission to a webhook or email. Set up an action. - [AI chat widget for your website](https://cntillion.com/docs/channels/website.md): Install the Centillion AI chat widget for website visitors with one snippet: a floating chat bubble or an inline chat. Set it up and test it today. - [UTM tracking](https://cntillion.com/docs/channels/utm-tracking.md): Keep campaign attribution when visitors follow links your agent shares. - [Shopify AI customer support chatbot](https://cntillion.com/docs/channels/shopify.md): Connect your Shopify store, add the chat with a theme app embed, and let your agent search products, update carts, track orders and handle returns. - [iOS and Android SDKs](https://cntillion.com/docs/channels/mobile-sdk.md): Add your agent to a native iOS or Android app with streaming replies, signed-in users, conversation history and app actions - [Connecting a channel](https://cntillion.com/docs/channels/overview.md): How messaging connections work, and what is true of all of them - [WhatsApp AI agent for customer support](https://cntillion.com/docs/channels/whatsapp.md): Connect a WhatsApp Business number through Meta so your agent answers customers, within the 24-hour window and with templates. Set it up and test it. - [AI text message support for US businesses](https://cntillion.com/docs/channels/sms.md): Get a registered US business number your customers can text, answered by your agent, with STOP and START handled for you. See how it works. - [Phone numbers for your AI agent](https://cntillion.com/docs/channels/phone.md): Import Twilio or SIP trunk numbers into your workspace, assign them to an agent, and answer calls with your chosen voice and greeting. - [Existing Centillion Labs numbers](https://cntillion.com/docs/channels/phone-numbers-from-centillion.md): Find existing managed numbers and get help with rentals and business verification - [Outbound AI calls](https://cntillion.com/docs/channels/outbound-calls.md): Run batch calls from an uploaded list or a campaign audience, with published agent instructions, calling limits and recipient results. - [Facebook Messenger AI chatbot for business](https://cntillion.com/docs/channels/messenger.md): Connect your Facebook Pages so your agent answers Messenger chats and Page comments become tickets. Learn the 24-hour rule and set it up. - [Instagram DM automation with AI](https://cntillion.com/docs/channels/instagram.md): Connect a Business or Creator account so your agent answers Instagram direct messages and comments become Helpdesk tickets. Set it up here. - [AI assistant in Slack for support teams](https://cntillion.com/docs/channels/slack.md): Add your agent to Slack so your team mentions it for answers in a thread, gets handoff alerts and replies to customers. Set it up here. - [Salesforce](https://cntillion.com/docs/channels/salesforce.md): Answer Salesforce cases by email or as drafts, escalate cases to your team, and hand website chats to Salesforce live chat - [Connect an AI agent to Zapier](https://cntillion.com/docs/channels/zapier.md): Send the leads your agent captures to your CRM through Zapier, or ask the agent for answers inside a Zap. Create a key and build your first Zap. - [AI email support agent](https://cntillion.com/docs/channels/email.md): Let your agent answer support email from a generated address, a forwarded company address, or a connected Gmail or Outlook inbox. Set up and test it. - [Email addresses and domains](https://cntillion.com/docs/channels/email-settings.md): Add a company address, verify automatic forwarding, and authenticate its domain - [Set up email forwarding](https://cntillion.com/docs/channels/email-forwarding.md): Route Google Workspace, Gmail, Microsoft 365, Yahoo, or Proton mail to your agent - [Authenticate an email domain](https://cntillion.com/docs/channels/email-dns.md): Publish DKIM, SPF, and DMARC records and validate your company sender - [Event listeners](https://cntillion.com/docs/developer-guides/event-listeners.md): React to messages, tool calls, dictation and runtime options from the website widget. - [Webhooks](https://cntillion.com/docs/developer-guides/webhooks.md): Receive call and conversation analysis events in your CRM, automation tool or backend, signed in the Standard Webhooks format. - [Import contacts CSV to your AI agent](https://cntillion.com/docs/customer-data/contacts.md): Contacts is the customer list your Centillion agent knows. Add or import people from CSV or Excel, define custom attributes and group them by churn reason. - [Sync AI agents with HubSpot or Salesforce](https://cntillion.com/docs/customer-data/crm-integrations.md): Connect HubSpot, Salesforce or Intercom so Contacts fill with your customers every 15 minutes and outcomes go back to the CRM. Connect your CRM. - [AI support agent with Stripe billing](https://cntillion.com/docs/customer-data/stripe.md): Connect Stripe so signed-in customers see their invoices and subscriptions in chat and change plans in the Stripe customer portal. Set up billing actions. - [Verify logged-in users in AI chat widget](https://cntillion.com/docs/customer-data/identity-verification.md): Sign your website users in to the Centillion widget with a JWT or user hash, so the agent links each chat to the right contact. Set up verification. - [Churn reasons](https://cntillion.com/docs/customer-data/churn-reasons.md): Find out why customers leave, from every conversation, and group them by reason - [Outbound calls and campaigns](https://cntillion.com/docs/campaigns.md): Upload a call list, choose an agent and published branch, schedule batch calls, or send WhatsApp messages. Review progress and every recipient result. - [AI helpdesk with human handoff](https://cntillion.com/docs/helpdesk.md): Centillion Helpdesk turns conversations your AI agent cannot finish into tickets. Set up teams, AI drafts and live takeover, and answer from one inbox. - [Helpdesk email settings](https://cntillion.com/docs/helpdesk/email-settings.md): Choose support addresses, sender names, signatures, and delivery alerts for your team - [Product issues in Notion](https://cntillion.com/docs/helpdesk/product-issues.md): Group support reports into one bug and keep its progress visible - [Zendesk email handoff](https://cntillion.com/docs/helpdesk/zendesk-email.md): Create Zendesk tickets from email conversations and resume AI replies when support resolves them - [Centillion on your phone](https://cntillion.com/docs/mobile.md): Install the app on a phone and get notified when a customer needs a person - [My agent is not answering](https://cntillion.com/docs/troubleshooting.md): Work through the causes in the order they actually happen - [Workspaces](https://cntillion.com/docs/workspaces/overview.md): Create a workspace, switch between workspaces, and leave one - [Conversations](https://cntillion.com/docs/workspaces/conversations.md): Review transcripts, branch history and analysis across your agents - [Voices](https://cntillion.com/docs/workspaces/voices.md): Find, preview and create voices for every agent in your workspace. - [Workspace settings](https://cntillion.com/docs/workspaces/settings.md): Change your workspace image, name, and URL, or delete a workspace - [Members and roles](https://cntillion.com/docs/workspaces/members.md): Invite your team, choose permissions, and transfer primary ownership - [Workspace usage](https://cntillion.com/docs/workspaces/usage.md): Track message credits by date and AI agent - [Plans and billing](https://cntillion.com/docs/workspaces/billing.md): Choose a plan, manage credits and add-ons, and review payments - [Guides to AI customer conversations](https://cntillion.com/docs/guides/overview.md): Practical guides to AI agents for customer conversations: phone, WhatsApp, outbound calls and more. Learn how each works, then try it in Centillion. - [AI outbound calling: consent, hours and disclosure](https://cntillion.com/docs/guides/ai-outbound-calling.md): What the law asks of AI outbound calls: consent, saying who is calling, calling hours and opt-outs. Learn the rules you are responsible for, then set up your calls. - [Answering WhatsApp customers with an AI agent](https://cntillion.com/docs/guides/whatsapp-ai-agent.md): How a WhatsApp AI agent works within Meta rules: the 24-hour window, templates, opt-in, AI policy and pricing. Learn them, then connect your number. - [AI phone answering on your own Twilio number](https://cntillion.com/docs/guides/ai-phone-answering.md): What an AI receptionist should do on a call, what callers expect, and when to pass the call to a person. Learn the basics, then put an agent on your number. - [Chatbot vs AI agent: what changes for customer support](https://cntillion.com/docs/guides/chatbot-vs-ai-agent.md): A chatbot answers from a script and ends the chat. An AI agent works for your business inside its rules. Learn the difference and build an agent. - [Shopify customer service automation: orders and returns](https://cntillion.com/docs/guides/shopify-ai-support.md): What Shopify shoppers ask, which answers an AI agent can give from live store data, and where a person stays in charge. Set it up on your store. - [How to train an AI chatbot on your own data](https://cntillion.com/docs/guides/train-ai-agent-on-website.md): How an AI agent learns from your website and documents, why answers go wrong, and how to keep knowledge tidy. Then add your own sources and test them. - [WhatsApp win-back campaigns: a practical guide](https://cntillion.com/docs/guides/whatsapp-win-back-campaigns.md): How WhatsApp win-back campaigns work: templates, opt-in, limits and what to measure. Then run one where your AI agent answers every reply. - [API reference](https://cntillion.com/docs/api-reference/introduction.md): Authenticated endpoints for Centillion agents and Helpdesk - [Developer API](https://cntillion.com/docs/api-reference/developer-api.md): Workspace API keys, streaming chat, agents, sources, conversations, customer data, and WhatsApp templates - [Real-time monitoring](https://cntillion.com/docs/api-reference/realtime-monitoring.md): Watch live conversations over a WebSocket and send control commands: end a call, transfer it, add context, or take over a chat - [Contacts and campaign enrollment](https://cntillion.com/docs/api-reference/contacts-and-enrollments.md): Push leads from your own systems and have them called by an always-open campaign - [Batch calling API](https://cntillion.com/docs/api-reference/batch-calls.md): Create, schedule and manage phone or WhatsApp voice batches, import recipients and retrieve call results. - [Agent testing API](https://cntillion.com/docs/api-reference/agent-testing.md): Manage reusable tests, run agent suites, and use verdicts and grouped results in CI - [Create a Helpdesk ticket](https://cntillion.com/docs/api-reference/endpoint/create-helpdesk-ticket.md): Open a Helpdesk ticket for a Centillion agent from your own systems - [Chat bubble controls](https://cntillion.com/docs/developer-guides/chat-bubble-control.md): Open, close and reset the website chat, override its display options, and listen for events ## OpenAPI Specs - [openapi](/docs/api-reference/openapi.json) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.