Lexicon: dictate to your agent and keep your spelling

It works where your voice lands: through MCP, in Claude Code, in the browser and on macOS. Setup takes about a minute. It asks how your company and your own name should be spelled, then registers itself with the agent clients it finds on your machine.

We measured it. In one test, 330 clips of synthesized speech went through whisper.cpp (small.en). The raw transcripts recovered 45.9 percent of proper nouns. Exact find-and-replace, like macOS Text Replacement, recovered 62.0 percent. Lexicon recovered 91.0 percent. In every case it wrongly changed 0 of 72 clean prose sentences.

Read the caveats too. The audio is computer-generated, so it is cleaner than a real microphone. Whisper's own prompt-hint feature is also a strong baseline, so Lexicon adds less on top of it. When the test included sentences built on purpose to trip the matcher, the false-change rate was 15.3 percent on the synthetic set. The README publishes every failing case.

Lexicon is MIT licensed and installs from npm as @ashlr/lexicon. The live demo runs the real matcher in your browser with nothing installed.

Most engineers now use several AI coding tools. Phantom puts them in one place, so you can work with an agent or hand it a goal and check the results.