sinth
The Premier Adult AI Communications Provider

Talk and chat with AI,
without boundaries.

One API for adult AI across chat, voice, calls, text, and email — under your brand. The engine behind 100+ adult brands, performing like your best chatter and never clocking out.

Powering NSFW conversations for 100+ brands and hundreds of thousands of people.

Everything people do, your AI does

One engine across every channel — with shared memory, personas, and guardrails.

Chat

Real-time text conversations with memory and personality.

Voice calls

Cloned, natural voices on live phone calls.

SMS / Text

Two-way texting on real numbers.

Web

Drop-in chat and voice widgets for any site.

Email

Inboxes that hold a conversation on their own.

One API

Every channel, every persona, behind a single key.

For operators & agencies

Your best chatter — cloned, on every channel, 24/7

Human chatters are expensive, inconsistent, and asleep half the day. sinth runs your personas across chat, voice, text, and DMs with shared memory and guardrails — on-brand every time. Operators on our networks have watched AI out-convert their human teams.

24/7
always on, zero burnout
concurrent conversations
100%
on-brand, on-script
18+
guardrails built in

Who builds on sinth

Operators & agencies

Run AI across your chatters' channels, A/B test it against your team, and white-label the whole thing as your own.

Creators & models

Clone your voice and personality, then let an AI keep fans engaged in DMs, texts, and calls — self-serve.

Developers

Grab a key and ship. Pay per use, scale when you're ready. Personas, memory, and moderation built in.

For developers

The API is the product

Sign up, grab a key, and ship. No sales call required — pay per use, scale when you're ready. Personas, memory, retrieval, and moderation are built in.

curl https://api.sinth.ai/v1/chat \
  -H "Authorization: Bearer sinth_live_…" \
  -d '{ "persona": "luna", "message": "hey there" }'

# → { "reply": "mmm hey you. been waiting…" }

Transparent, usage-based

$10 to start · $0.02 per action · no subscriptions · credits never expire

Try it yourself

Chat with a synthetic companion or call one — then build your own on the same engine.