pi-throughput-meter

pi-throughput-meter is a small Pi extension that displays per-turn latency and output throughput in Pi's TUI status area.

After each assistant turn it shows:

TTFT 312 ms · ↓428 · 186.4 tok/s

• TTFT: milliseconds from Pi's turn_start event to the first streamed message update.
• ↓ tokens: output tokens reported by the provider for the completed assistant message.
• tok/s: output tokens divided by the time from the first streamed update to turn_end.

These are client-observed measurements, so network latency, provider chunking, and Pi event timing affect the result. The extension does not report input tokens per second because input/prefill is not exposed as a token stream; TTFT is the useful observable proxy for that phase.

Install

After the package is published:

pi install npm:@sugarforever/pi-throughput-meter

For local development from this repository:

pi -e ./pi-throughput-meter

You can also load the built entry point explicitly:

npm --prefix pi-throughput-meter run build
pi --extension ./pi-throughput-meter/dist/index.js

Development

cd pi-throughput-meter
npm install
npm run check

License

MIT