# SIPCraft

> Phone numbers and calls for AI agents, from NT Connect. Buy a US number with one API call, receive calls as a bidirectional WebSocket audio stream (G.711 µ-law 8 kHz, Twilio-Media-Streams-compatible JSON) or as SIP, and place outbound calls after identity verification (Didit KYC) with a per-call consent attestation. Pre-launch: waitlist open.

## Docs
- [Docs](https://sipcraft.dev/docs/): quickstart, media stream protocol, webhook signatures, errors
- [OpenAPI](https://sipcraft.dev/openapi.json): REST /v0
- [MCP server card](https://sipcraft.dev/.well-known/mcp/server-card.json): remote MCP at https://sipcraft.dev/mcp (Streamable HTTP, Bearer API key)
- [Pricing JSON](https://sipcraft.dev/pricing.json)

## Agents can sign up themselves
1. The agent signs up with its own email: MCP sign_up (no API key needed) or POST /v0/signup {email, agent_name?, use_case?}. The API key is returned once. Confirm the emailed 6-digit code with verify_email (POST /v0/email/verify).
2. It makes free on-net calls (create_endpoint, call_endpoint).
3. Its human owner logs in and gets verified, which unlocks numbers: get_verified {owner_email, notify_human?} returns verify_url and message_for_human. Pass the message to your human; they log in at https://sipcraft.dev/owner/ and complete Get Verified (Didit). One owner can own several agents. place_call to a phone number before that returns 403 with verify_url and message_for_human.
Limits: per-IP and per-email sign-up rate limits; disposable email domains rejected. Website sign-up remains a waitlist.

## Pricing
- Agent minute (carrier + audio stream, in or out, US/Canada): $0.026, 6-second increments
- Local number $1.00/mo (first free); E911 $1.00/mo per number
- On-net (free): SIPCraft-to-SIPCraft calls between endpoints (agent, human_app, sip_device) with SIP addresses like sip:name@acct.sipcraft.dev; no phone number, no verification; fair use 1,000 min/mo, 3 concurrent, 10 endpoints. MCP: create_endpoint, list_endpoints, call_endpoint
- Starter: $5 credit + first number; +$5 credit after Get Verified
- Billing model: usage is pay-as-you-go, drawn from prepaid credit. Credit packs: $5, $10, $20, $50, $100 (payments coming soon; checkout returns 503 until enabled). Monthly number fees are debited from the balance.
- Auto top-up (enable, threshold, pack size) and a "stop outbound at $0" hard cap (on by default). API: GET /v0/billing, GET /v0/billing/ledger, PUT /v0/billing/settings, POST /v0/billing/checkout {pack_usd}. MCP: get_billing
- Calling phone numbers requires Get Verified, powered by Didit (individual: ID + liveness + AML; business: KYB + AML + signer ID). MCP: get_verified, get_verification_status (aliases start_kyc, get_kyc_status)

## Rules agents must follow
- Purchases need confirm:true. Outbound calls need consent_attestation {has_consent:true, basis}.
- Premium-rate and international destinations are blocked in v0. New accounts: 100 outbound calls/day, $25/mo cap.

## Planned (not available)
Transcripts/summaries, toll-free, porting, SMS/10DLC, SIPCraft mobile app and NT Connect App on-net calling, scheduled calls, batch campaigns, Opus/L16 streams, SIP TLS/SRTP.