The CPaaS your CFO will sign off on.
A Communications Platform as a Service — programmable voice, virtual numbers, AI agents, outbound campaigns, webhooks and a clean REST API — running entirely inside your own Windows / IIS server, over your own SIP trunks. No per-minute SaaS markup. No tenant data crossing the public cloud. Same surface third-party CPaaS vendors charge for, on your hardware.
REST API v1
POST a phone number + a system prompt and the platform dials, attaches a real-time voice AI, emails the transcript. GET to list calls, virtual numbers, transcripts. Bearer-token auth, JSON in and out, single-line curl examples.
Webhooks
Subscribe to call.ended, transcript.saved, outbound-ai.finished and seven other lifecycle events. HMAC-signed deliveries, automatic retry with exponential backoff, auto-pause after consecutive failures. Validates with a test-fire button.
Real-time voice AI
Inbound numbers answered by a live voice agent that speaks any language, follows the script you wrote, transfers to human SIP phones, and emails you the transcript. Same engine powers outbound campaigns — appointment reminders, post-stay surveys, payment chasing.
BYOC SIP bridge
Bring your own SIP trunks (FRITZ!Box, BTS, retail carriers, whatever). The platform layers programmable telephony on top — you keep the carrier relationship, the per-minute economics, and the geographic routing you already negotiated.
Sovereign data path
Tenant data — prompts, transcripts, call records, webhook events — never leaves your server. No third-party CPaaS vendor sits between you and your carrier. GDPR / NIS2 / DORA compliance is a property of your existing setup, not a fight with someone else's privacy policy.
One-time license, not per minute
Pay once for the platform, then pay only your carrier for the actual minutes used. Compare against $0.014/min for inbound + $0.024/min for outbound on the big CPaaS vendors — on a 50k-min/month workload, the platform pays for itself in weeks.
The CPaaS API in three commands
Bearer token from /oidc.ashx, then any of:
# Initiate an outbound AI call
curl -X POST https://www.aloaha.com/api.ashx/v1/calls \
-H "Authorization: Bearer $TOKEN" \
-H "Content-Type: application/json" \
-d '{
"phone": "+15551234567",
"displayName": "Reminder",
"email": "ops@example.com",
"systemPrompt": "You are calling Alex to remind them about a test appointment tomorrow at 14:00.",
"apiKey": "AIza...",
"voice": "Aoede",
"language": "en-US"
}'
# List active + recent calls
curl -H "Authorization: Bearer $TOKEN" \
https://www.aloaha.com/api.ashx/v1/calls
# Fetch the full transcript of a finished call
curl -H "Authorization: Bearer $TOKEN" \
https://www.aloaha.com/api.ashx/v1/transcripts/oac-2f9e1b7c3a48Every endpoint has a single-line curl example and a complete request / response body in the REST API reference.
How CodeB compares with Twilio, Vonage, Plivo
The feature set is similar; the operating model is different.
| Capability | CodeB (self-hosted) | Hyperscaler CPaaS |
|---|---|---|
| Programmable outbound voice | REST + AI prompt + webhooks | REST + TwiML / NCCO + webhooks |
| Inbound voice AI receptionist | Built-in, per-number, your prompt | External AI service + Studio flow |
| SIP trunks | Bring your own (FRITZ!Box, carrier, IP-PBX) | Buy minutes from the vendor |
| Per-minute price | 0 — you pay your carrier directly | $0.014–0.024/min inbound + outbound |
| Data residency | On your server, your jurisdiction | US-east / EU-west / multi-region cloud |
| Recording & transcripts | On disk, JSON, full conversation | Per-recording fee, vendor storage |
| Number portability | Your carrier — you already control the DID | Vendor lock-in on numbers bought from them |
| Custom prompts & personas | Plain text files; hot-reload per vnum | Studio flows + extra AI subscription |
| Test-fire webhook from admin UI | Yes — one click, full HMAC validation | Vendor docs, no in-product simulator |
| License model | One-time, per server | Pay-as-you-go forever |
Workloads it’s built for
The biggest cost reduction comes from outbound voice campaigns. A 15-second appointment reminder over a CPaaS vendor: $0.006 outbound + $0.0035 AI ≈ $0.01 per call — on 200,000 reminders/month, ~$2,000/month. On CodeB: free, minus the carrier minutes you were paying anyway.
- Healthcare — appointment reminders, prescription refill nudges, post-visit follow-ups.
- Hospitality — pre-arrival check-in calls, post-stay surveys, restaurant no-show prevention, hotel wakeup calls.
- SaaS — trial-expiry nudges, expansion outreach, churn save campaigns, support callbacks.
- Financial services — payment reminders, fraud alerts (voice second factor), KYC interview scheduling.
- Operations — on-call escalations, dispatch confirmations, supply-chain status calls.
- Inbound — AI receptionist front desk, multi-language IVR replacement, after-hours coverage.
Full catalogue with sample prompts: 15 outbound AI workflows →
Architecture in one paragraph
One Windows server runs IIS plus a Windows Service called CodeBSipBridge. IIS serves the meeting room, admin pages, and the REST API. The bridge holds the SIP UAS / UAC against your trunks, registers SIP phones (sovereign-SBC functions documented at sbc.html), and runs the AI voice sessions (one WebSocket per active call). When a call ends or a transcript saves, the bridge fires the corresponding webhook to your configured URL within ~50 ms. There is no third-party message bus, no managed cloud, no SaaS dependency. The whole thing can run air-gapped if your carrier accepts a private SIP peer.
Want to see it on your own carrier?
Drop us a line with your trunk type and we’ll show you the REST + webhook surface against a sandbox tenant the same day.
Frequently asked questions
What is CodeB Self-hosted CPaaS?
CodeB Self-hosted CPaaS is a Communications Platform as a Service that runs entirely inside your own Windows / IIS server, over your own SIP trunks. CodeB provides programmable voice, virtual numbers, AI agents, outbound campaigns, webhooks and a REST API. There is no per-minute SaaS markup and no tenant data crossing the public cloud.
How is CodeB CPaaS different from Twilio, Vonage or Plivo?
CodeB offers a similar feature set to Twilio, Vonage or Plivo with a different operating model. CodeB runs on your own server, uses SIP trunks you bring instead of minutes bought from the vendor, charges no per-minute price, and keeps data residency in your own jurisdiction. It is licensed one-time per server instead of pay-as-you-go.
How is CodeB CPaaS priced?
CodeB CPaaS uses a one-time licence per server; after that you pay only your carrier for the minutes actually used. The CPaaS page compares this with about $0.014 per minute inbound and $0.024 per minute outbound on the large CPaaS vendors.
What can the CodeB CPaaS REST API do?
The CodeB REST API v1 lets you POST a phone number and a system prompt so the platform dials, attaches a real-time voice AI and emails the transcript. GET requests list calls, virtual numbers and transcripts. Authentication uses a bearer token from /oidc.ashx, with JSON in and out.
Which webhooks does CodeB CPaaS support?
CodeB CPaaS webhooks cover call.ended, transcript.saved, outbound-ai.finished and seven other lifecycle events. Deliveries are HMAC-signed, retried automatically with exponential backoff and paused automatically after consecutive failures. A test-fire button in the admin UI validates the setup.
Which SIP trunks can I use with CodeB CPaaS?
CodeB CPaaS is bring-your-own-carrier: you can use a FRITZ!Box, BTS, a retail carrier or an IP-PBX. You keep the carrier relationship, the per-minute economics, the geographic routing you negotiated and control of your DIDs.
Where does CodeB CPaaS store data?
CodeB CPaaS keeps tenant data such as prompts, transcripts, call records and webhook events on your own server. No third-party CPaaS vendor sits between you and your carrier, so GDPR, NIS2 and DORA obligations are handled within your existing setup. When you use the voice AI, call audio streams to the real-time voice provider you configure.
What does the CodeB CPaaS architecture look like?
CodeB CPaaS runs on one Windows server with IIS plus a Windows Service called CodeBSipBridge. IIS serves the meeting room, admin pages and REST API, while the bridge handles SIP towards your trunks, registers SIP phones and runs the AI voice sessions. Webhooks fire within about 50 ms of a call ending or a transcript being saved.
Can CodeB CPaaS run air-gapped?
Yes. CodeB CPaaS has no third-party message bus, managed cloud or SaaS dependency, so it can run air-gapped if your carrier accepts a private SIP peer.
What workloads is CodeB CPaaS built for?
CodeB CPaaS brings the biggest cost reduction on outbound voice campaigns such as appointment reminders. Typical workloads span healthcare, hospitality, SaaS, financial services and operations, plus inbound uses such as an AI receptionist front desk, multi-language IVR replacement and after-hours coverage.
How do I evaluate CodeB CPaaS?
Contact CodeB with your trunk type, and the team will show you the REST and webhook surface against a sandbox tenant the same day. The full endpoint list with curl examples is in the REST API reference.