One API for calls, SMS, and AI — built for modern teams.
Ringflow's REST API gives you programmatic control over every part of your communications stack — outbound calls, bulk SMS, dual-channel recordings, AI Receptionist agents, and real-time event webhooks — all behind a single authenticated endpoint.
curl -X POST https://api.ringflow.com/v2/calls \
-H "Authorization: Bearer $RINGFLOW_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"to": "+14155550199",
"from": "+19172544289",
"recordDualChannel": true,
"aiReceptionistId": "agent_rfw_support"
}'
# 201 Created
{
"id": "call_rfw_2Kj8mNpQ",
"status": "ringing",
"to": "+14155550199",
"recording": true,
"ai": true
}Everything you need, nothing you don't.
Six resource groups, one base URL, one authentication scheme. Every endpoint is versioned, returns consistent JSON, and ships with request/response examples in the full reference.
- POST/v2/calls— Place outbound call to any number
- GET/v2/calls/:id— Fetch live status, duration & recording
- POST/v2/calls/:id/transfer— Warm or cold transfer mid-call
- DELETE/v2/calls/:id— Terminate an active call immediately
- POST/v2/messages— Send SMS or MMS to a single recipient
- POST/v2/messages/bulk— Batch up to 1 000 messages per request
- GET/v2/messages/:id— Poll delivery status and carrier receipt
- POST/v2/calls/:id/record— Start dual-channel call recording
- DELETE/v2/calls/:id/record— Stop recording and trigger storage
- POST/v2/recordings/:id/transcribe— Request async AI transcription
- POST/v2/ai/agents— Provision a new AI Receptionist
- PUT/v2/ai/agents/:id/knowledge— Push FAQs, docs & escalation rules
- GET/v2/ai/sessions/:id/summary— Retrieve post-call AI summary
- POST/v2/events/subscriptions— Subscribe to any platform event
- GET/v2/events/subscriptions— List and filter your subscriptions
- DELETE/v2/events/subscriptions/:id— Remove an event subscription
- POST/v2/auth/tokens— Issue short-lived bearer token
- POST/v2/auth/keys— Create scoped workspace API key
- PUT/v2/auth/keys/:id/rotate— Zero-downtime key rotation
Idiomatic clients for your stack.
Every Ringflow SDK is built code-first — not generated from a spec. Retries, pagination cursors, and webhook verification are first-class, not afterthoughts.
import { Ringflow } from "@ringflow/sdk"
const client = new Ringflow({
apiKey: process.env.RINGFLOW_API_KEY,
region: "us-east-1",
})
// Place a call and stream status updates
const call = await client.calls.create({
to: "+14155550199",
from: "+19172544289",
recordDualChannel: true,
onStatus: (evt) => console.log(evt.status),
})
console.log(call.id) // call_rfw_2Kj8mNpQPredictable limits at every tier.
Limits are enforced per workspace, not per IP. Every response carries X-RateLimit-Remaining, X-RateLimit-Reset, and a Retry-After header on 429s so you can back off gracefully.
| Plan | Sustained | Burst cap | Concurrent calls |
|---|---|---|---|
| Sandbox | 5 req/s | 15 req/s | 2 calls |
| Starter | 40 req/s | 80 req/s | 25 calls |
| Business | 150 req/s | 300 req/s | 150 calls |
| EnterpriseCustom | Custom | Custom | Unlimited |
Built different. Priced fair.
Most telephony APIs bolt AI on as an afterthought. Ringflow built AI, voice, and messaging from the ground up as a single coherent API — so you don't duct-tape three vendors together.
| Capability | Ringflow | Typical alternative |
|---|---|---|
| Unified calling + SMS + AI in one API | ✕ | |
| Permanent sandbox — no expiry, no card | ✕ | |
| Dual-channel recording out of the box | ✕ | |
| AI Receptionist via REST endpoint | ✕ | |
| HMAC-signed webhook deliveries | ||
| Zero-downtime API key rotation | ✕ | |
| Enterprise security audit + BAA available | ✕ |
Our Commitment
A REST API built to production standards.
Ringflow's API is designed to handle real production workloads — consistent JSON responses, strong authentication, clear rate limit signalling, and a permanent sandbox for safe integration testing.
Loved by engineering teams across industries.
From healthcare to retail — Ringflow's API powers production communications at scale.
Arjun Mehta
Head of Engineering, Zenia Health — Mumbai
“Ringflow's API let us embed voice triage into our patient portal in two weeks. The AI Receptionist endpoint alone cut our after-hours call volume by 40%.”
Rachel Torres
VP of Product, ClearLane Finance — Austin TX
“We migrated three contact centre vendors onto Ringflow in one quarter. The unified REST surface made our integration straightforward — one auth flow, one webhook schema, everything.”
Ben Hargreaves
Platform Lead, StackRoute — London
“The dual-channel recording and async transcription endpoints saved us from building our own speech pipeline. Ringflow just handles it, and the latency is genuinely impressive.”
Nadia Yusupova
CTO, Orbis Retail — Dubai
“Our SMS bulk endpoint sends 50 000 order confirmations daily without a hiccup. Delivery receipts land in our webhook within seconds — exactly what retail ops demands.”
Tom Fitzgerald
Senior Backend Engineer, Lawbridge — Chicago IL
“Key rotation with zero downtime was the feature that sold our security team. Rolling API keys without a maintenance window is something our old provider simply couldn't do.”
Soo-Jin Park
Solutions Architect, Clearview SaaS — Seoul
“The Go SDK is idiomatic and compiles clean on every CI run. Context cancellation, retries, and rate-limit back-off work exactly the way you'd expect a first-class client to behave.”
अक्सर पूछे जाने वाले प्रश्न
Frequently Asked Questions
सक्रिय रूप से अक्सर पूछे जाने वाले प्रश्नों का उत्तर देने से उपयोगकर्ता का विश्वास बढ़ता है और समर्थन टिकटों में कटौती होती है।
Voice, SMS, and AI — all wired up before lunch.
Free trial · No card · Free number porting · SLA-backed uptime