pi-tps-meter

Tokens per second meter for pi CLI with sparkline visualization.

Install

pi install npm:pi-tps-meter

Features

During streaming — a smooth, animated gauge that fills with live speed (1/8-cell resolution, auto-scaled to your session's peak):

⠹ ▕███████▋···▏ 47 tps

After a message — a min-max normalized sparkline of your last 12 messages (newest on the right) plus aggregate stats:

▁▄▇▅▂▁▇█▅▃▆▇ 42 tps · μ 39 · p95 61

Color coding:

• 🟢 Green: >50 tps (fast)
• 🟡 Yellow: 20-50 tps (medium)
• 🔴 Red: <20 tps (slow)

Accuracy

• Uses the provider's real output token count (message.usage.output); the char/4 estimate is only a fallback for providers that don't report usage
• Rate is measured from the first token, so time-to-first-token (network/queue latency) doesn't drag down the reported tps
• Tracks thinking tokens (thinking_delta) alongside text, so models with extended thinking report accurate generation speed

Stats

• avg: rolling 60-second window (resets older samples)
• μ: all-time mean across the session
• p95: 95th percentile, all-time (up to 500 samples)

Optimizations

• Single shared 200ms timer, torn down on both message_end and agent_end (no runaway timer if a stream is aborted)
• Fixed-size circular buffers (no allocations in the streaming repaint path)
• Memoized sparkline (rebuilt once per message, not on every tick)
• Insertion sort for p95 (cold path, runs once per message for ≤500 elements)

Author

Venkata Sai Chirasani

License

MIT