Guides & engineering notes

WhatsApp for AI agents and phone systems

Step-by-step guides to connect WhatsApp to Claude, ChatGPT, Cursor, Grok and your PBX, plus the engineering behind it: SIP bridging, the MLow voice codec, webhooks and per-number egress.

Connect Asterisk to WhatsApp with a QR Code
SIP Trunking Oct 1, 2026 · 11 min read

Connect Asterisk to WhatsApp with a QR Code

Step-by-step: link WhatsApp by QR code, then connect Asterisk PJSIP so WhatsApp calls ring your phones and your users dial WhatsApp numbers.

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The MLow codec in pure Go — a clean-room encoder and decoder for Meta's low-bitrate voice codec. WhatsMCP Engineering.
Audio Codecs Sep 11, 2026 · 13 min read

Rebuilding MLow: WhatsApp's Voice Codec in Pure Go

How we built a clean-room, pure-Go encoder and decoder for MLow — Meta's low-bitrate codec behind billions of WhatsApp, Messenger and Instagram calls: the hybrid SILK/CELT structure, reverse-engineering it against the live library, and frame-exact validation.

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Bridging WhatsApp and the PBX — a low-latency SIP trunking bridge. WhatsMCP Engineering.
SIP Trunking Sep 11, 2026 · 12 min read

Bridging WhatsApp and PBX: Low-Latency SIP Trunking Internals

A deep technical tour of the real-time transcoding bridge that connects WhatsApp calls to Asterisk and FreeSWITCH: dual-plane signaling, Opus/G.711 transcoding, jitter buffering, PLC, a sub-50 ms media path, and the war stories behind each decision.

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