Arka

Flow-based Communication over Every Channel

Arka is an open framework and orchestration engine for flow-based communication across Email, WhatsApp, SMS, Slack, and Microsoft Teams — designed to run in every common environment, deliver messages at in-memory speed, and scale to any volume.

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Arka Capabilities

Built for production communication

Everything you need to run reliable, compliant, high-volume messaging — from a developer's laptop to a global enterprise deployment.

Delivery Guarantees

Exactly-once delivery semantics
At-least-once fallback modes
Per-channel delivery receipts
Idempotency keys

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Layered APIs

Declarative YAML flows
REST API and webhooks
SDKs for JS, Python, Java
Visual flow builder

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Multi-Channel

Email, WhatsApp, SMS
Slack, Microsoft Teams
Channel-agnostic routing
Fan-out and fallback

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Operational Focus

High-availability clusters
Savepoints and replay
Flexible deployment
Full audit trail

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Scale & Performance

Low-latency routing
High-throughput queues
Scale-out architecture
Incremental checkpoints

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Use Cases

What teams build with Arka

Event-driven Messaging

React to user events — signups, orders, payments, alerts — with consistent, multi-channel outreach. One event, many channels, zero duplicated logic.

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Bulk Communication Pipelines

Send thousands (or millions) of messages from a recipient list with rate-limited, retry-safe pipelines. Campaigns, announcements, password resets at scale — all with delivery analytics.

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Two-way Conversations

Build interactive bots, support threads, and notification-driven workflows with round-trip messaging. Session state and conversation context are managed for you.

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Recent updates

Recent Arka blogs

April 8, 2026 Arka Team

Arka 1.4.0 Release Announcement

The Arka Community is excited to announce the release of Arka 1.4.0. This release brings new flow templates for customer-onboarding, improved retry semantics for transient failures, and first-class support for the Microsoft Teams 2025 messaging API…

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March 22, 2026 Arka Team

WhatsApp Business API Connector — Deep Dive

We recently added first-class WhatsApp Business API support to Arka. In this post we walk through template-message approval workflows, the 24-hour session window, and how Arka's rate-limiter prevents deliverability penalties across large tenants…

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March 1, 2026 Arka Community

Arka Community Update — March 2026

This is the monthly Arka Community update for March 2026. It covers the main developments in the community over the past month, including the OSS Small Firm edition launch, new channel connector proposals, and updates from the contributors' working group…

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