I build voice AI agents that answer real phone calls.

My work sits where telephony meets language models: real calls over real carriers, real APIs, real video in the browser, built on the SignalWire AI Agents SDK. The phone network is a century of accumulated engineering discipline and it is unforgiving in the way good infrastructure should be. Teaching it to think is the most interesting problem I've been handed.

I came to it from the PBX side, after a decade of FusionPBX and FreeSWITCH, and that decides the order I build in: prove the thing end to end on real infrastructure first, then make it elegant. A demo that survives a live call has earned the right to look good.

Pittsburgh, PA.

Eleven years of open-source contribution, primarily across FusionPBX, FreeSWITCH and SignalWire.

Of the merged pull requests, 1,390 landed in public repositories (97%) and 36 in private ones (3%). The public ones:

Plus smaller sets in freeswitch/verto-client, freeswitch/freeswitch-sounds, signalwire/libstirshaken and signalwire/docs-legacy.

Chess is mine start to finish. Sidecar began as an earlier prototype from Brian; I did the bulk of the build.

Team projects I contributed to. Every one of them is live: call it, or click the video button and talk in the browser. They answer.

Maker challenges and stage tooling built for ClueCon, the annual FreeSWITCH and telephony developer conference. Once a year the industry gathers in one room, and I try to give it something hands-on to build.

2026 · The Prompt Pit · sole author An esports-style control room for the Vibe Coding Championship. A single container drives every screen in the house (stage, scoreboard, admin) and lets the entire audience vote from their phones three ways: on the web, by SMS, or by ringing a number and telling an AI agent who they are backing. The prototype challenges, five callable agents that contestants had to bend to their will, live in their own repo.

2026 · Buzzword Bingo · sole author Live audience bingo for conference talks. Scan a QR, draw a card that locks to you, and blot buzzwords as the speaker says them. Positive buzz counts for sound engineering and responsible AI, negative for hype, and AI product names are a free-for-all. The room's collective sentiment updates on stage in real time, which speakers enjoy right up until the hype column starts filling in.

2025 · Coder Games, Maker Challenge · sole author The SignalWire Maker Challenge for ClueCon Coder Games: an ESP32 whose LEDs answer to the phone network, one sketch driven by an inbound SMS and another by a voice call. It ships with the wiring diagram and a credentials scaffold, so entrants spend the hour on the idea rather than the boilerplate. Paired with an LED control agent that takes colour and on/off state by voice.

2024 · FreeSWITCH ClueCon Lab · contributor Brought the hands-on FreeSWITCH lab up to date for the conference: moved the image to Debian bookworm, took the IPv6 profiles out of the load path, and corrected the docker-compose and event-socket config so the lab came up clean for attendees. 2023 · Maker Challenge, ESP32-S3 · sole author Place a phone call from a button press. Five sketches that climb from "the board joined wifi, send an SMS" up to a physical button dialling out, with an optional temperature reading along for the ride. Parts list, wiring photos and a write-up for each one.

Small boards with something to say to the phone network. Most of them are well grounded.

• FusionPBX + Jitsi Meet: embedding a Jitsi room inside FusionPBX

More at len-pgh.github.io