CallFire API vs FreeSWITCH

CallFire API v2 is a REST API for connecting applications to CallFire telephony services. It accepts requests from any HTTP client and returns JSON, with support for individual and broadcast text and voice messaging. Developers can use webhooks for notifications such as campaign events and incoming texts. The documentation also covers contacts, phone number and keyword ordering, a sound library, short codes, and action states and results. Listed service features include campaign management, scheduling controls, call recording, and real-time reporting. SDKs are listed for Java,.NET, JavaScript, Python, and PHP; the JavaScript, Python, and PHP SDKs are marked beta. API access uses separately generated HTTP Basic Authentication credentials, so standard CallFire interface credentials do not work for API access. CallFire says API communications use HTTPS with TLS and webhook calls use SSL certificates. The service lists Do Not Call list management, 24/7 support, and advertised 99.95% uptime. Calls and texts stop when an account allowance reaches zero, and additional credits can be purchased at 6¢ per credit. Plans include Pay as you go at free, Lite at $99 a month, Startup at $199 a month, Grow at $299 a month, and Pro at $599 a month.

FreeSWITCH is an open-source framework for real-time voice and video communications. It can route calls, bridge video, transcode media, and connect protocols, and is designed for use in carriers, contact centers, and communication products. Its Event Socket exposes call control, channel management, and internal events to external processes over TCP. Integrations include HTTP backends, embedded Lua, Perl, Python, JavaScript, Java, and SignalWire connectivity. The mod_signalwire module connects to SignalWire for inbound and outbound PSTN calling over a persistent WebSocket session. Linux installation guidance covers Debian and Ubuntu using SignalWire packages or a source build. A free SignalWire account is required to access packages and downloads. FreeSWITCH is licensed under MPL 2.0 and can run in production at no cost; self-hosting requires dedicated resources to maintain on-premises infrastructure. The open-source edition has community support, while FreeSWITCH Pro offers commercial support, hardened builds, priority patches, and commercial modules including answering machine detection and licensed G.729 Annex A encoding and decoding.