JustCall API
JustCall documents a self-serve REST v2.1 API at developer.justcall.io spanning calls, SMS, WhatsApp, contacts, and AI insights. Auth is HTTP Basic with a per-account key pair. Webhooks require the Team plan, and rate limits scale by tier from 200 to 800 req/hr.
Frequently asked questions
JustCall scores D+ on the API Report Card. JustCall documents a self-serve REST v2.1 API at developer.justcall.io spanning calls, SMS, WhatsApp, contacts, and AI insights. Auth is HTTP Basic with a per-account key pair. Webhooks require the Team plan, and rate limits scale by tier from 200 to 800 req/hr.
Without a usable official API, teams fall back on manual exports, file drops, or one-off vendor integrations. The other option is an unofficial API layer like Supergood that automates the authenticated web app directly.
JustCall is a cloud-based business phone system and AI-powered customer communications platform that bundles inbound/outbound voice, SMS/MMS, WhatsApp, a multi-mode Sales Dialer (manual/auto/predictive/power), IVR/ACD, AI voice agents, call recording and transcription, real-time agent coaching (AI Copilot), sentiment analysis, conversation scoring, and multi-channel workflow automation into a single SaaS product.
Vertical: VoIP / business phone system / sales engagement (horizontal SaaS, not industry-specific). Sales and support agents log in via web, desktop, or mobile apps (plus Chrome extension and CTI dialer SDK) and make/receive calls, send SMS/MMS and WhatsApp messages, and run outbound dialing campaigns through the Sales Dialer in manual, auto, predictive, or power modes.
JustCall reports 6,000+ business customers globally and is rated 4.3/5 on G2 with 2,000+ reviews, putting it firmly in the second tier of business VoIP behind RingCentral, Zoom Phone, 8x8, Aircall, and Dialpad but ahead of niche players.
Yes, for any sales, support, or customer success team that runs on it, JustCall is the system of record for the entire conversational dataset: every inbound and outbound call with recording and AI transcript, SMS/MMS thread history, WhatsApp Business conversations, voicemails, dialer campaign outcomes and dispositions, IVR/ACD routing logs, agent activity and presence, AI Copilot scorecards and sentiment/topic analysis, contact and lead records (often the de facto CRM for SMB teams that use JustCall as their primary stack), call dispositions and notes synced to HubSpot/Salesforce/Pipedrive, number inventory across 70-90+ countries, and billing/usage records.
Founded 2016 in Palo Alto / Noida by Gaurav Sharma as part of SaaS Labs (Sharma previously founded HelloSociety, acquired by The New York Times).
Rate limits are aggressive and tier-gated (200 req/hr on Team, 400 on Pro, 800 on Business) with hard 429s on burst limits as low as 8 req/min. Webhooks are not available on the entry-level Essentials/Standard tiers, programmatic integration effectively requires the Team plan or above. Full sourced list under Sources below.
Common alternatives include RingCentral, Zoom Phone, 8x8, Dialpad, Aircall, Nextiva. Graded alternatives appear under "More from the report card" below.
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.