Cost Summary

Every session in Ptah has a live cost summary — tokens consumed, dollars spent, messages exchanged, and wall-clock duration. It’s visible per session in the header, and aggregated across sessions in Analytics.

Cost summary card

What’s tracked

Metric	Description
Input tokens	Tokens sent to the model (prompts, tool results, history)
Output tokens	Tokens returned by the model
Cache read tokens	Tokens served from prompt cache (billed at a discount)
Cache write tokens	Tokens written to prompt cache
Total cost (USD)	Provider-priced sum of all token classes
Message count	User + assistant + tool turns
Duration	First-message to last-message wall-clock time
Active duration	Time actually spent generating, excluding idle

Where to find it

Session header

A compact cost badge sits next to the session title. Hover for the full breakdown.

Session analytics tab

Each session row in analytics shows totals. Click the row to see per-turn breakdown.

Status bar

The global status bar shows today’s running cost across all sessions. Click it to open the analytics dashboard scoped to today.

Per-turn breakdown

Expand any message to see the exact cost of that turn:

Turn 14 — backend-developer
  Input:   12,480 tokens  ($0.1872)
  Cached:   8,100 tokens  ($0.0243)
  Output:   1,240 tokens  ($0.1860)
  Total:               $0.3975

This is especially useful for spotting expensive single turns (big tool outputs, long pasted files) so you can adjust context.

How pricing is computed

Costs come from the provider’s reported usage. When a provider doesn’t return a per-call price, Ptah applies the public list price for that model at the time of the call. You can override pricing per model in:

{
  "ptah.pricing.overrides": {
    "claude-opus-4-7": {
      "inputPer1M": 15.0,
      "outputPer1M": 75.0,
      "cacheReadPer1M": 1.5,
      "cacheWritePer1M": 18.75
    }
  }
}

Overrides are applied going forward; historical records keep the price they were recorded with.

Budgets and alerts

Set a daily cost budget in Settings → Sessions → Budget:

{
  "ptah.budget.dailyUsd": 25,
  "ptah.budget.warnAtPercent": 80,
  "ptah.budget.blockOverBudget": false
}

Warn — banner in the status bar at 80% of budget
Block — when enabled, new turns are paused at 100% until you raise the budget or wait for the next day

Exporting

The cost column is included in Session history exports (CSV and JSON). You can pipe CSV into your spreadsheet of choice for finance reporting.

Privacy

Cost data is local to your machine. Ptah does not report usage or spend to any external service.