pi-costs

Analyze cost and token usage from pi coding agent sessions.

Reads the JSONL session logs stored in ~/.pi/agent/sessions/ and produces a summary of costs, token usage, and breakdowns by model, project, day, or individual session.

Usage

Run directly with bunx (no install needed):

bunx @psg2/pi-costs

Or install globally:

bun install -g @psg2/pi-costs
pi-costs

Options

pi-costs                        All projects, last 7 days
pi-costs --days 30              Last 30 days
pi-costs --days 0               All time
pi-costs --project my-app       Filter by project (substring match)
pi-costs --sessions             Show per-session breakdown
pi-costs --daily                Show per-day breakdown
pi-costs --dir <path>           Custom sessions directory

Example output

======================================================================
  Pi Session Costs — last 7 days
======================================================================

  Total cost:       $42.5100
  Sessions:         18
  LLM requests:     320
  Input tokens:     50.2K ($0.2510)
  Output tokens:    1.2M ($30.0000)
  Cache read:       15.0M ($9.0000)
  Cache write:      800.0K ($3.2590)

  ──────────────────────────────────────────────────────────────────
  By Model:
  Model                                              Cost  Requests
  ──────────────────────────────────────────────────────────────────
  claude-opus-4-5                                $30.1200       210
  claude-sonnet-4-5                              $12.3900       110

  ──────────────────────────────────────────────────────────────────
  By Project:
  Project                                            Cost  Requests
  ──────────────────────────────────────────────────────────────────
  my-web-app                                     $28.4500       200
  my-api-server                                  $14.0600       120

======================================================================

How it works

Pi stores session logs as JSONL files in ~/.pi/agent/sessions/<project>/. Each assistant message includes a usage field with token counts and pre-calculated costs in USD:

{
  "type": "message",
  "message": {
    "role": "assistant",
    "model": "claude-opus-4-5",
    "usage": {
      "input": 3183,
      "output": 104,
      "cacheRead": 50000,
      "cacheWrite": 4000,
      "cost": {
        "input": 0.0159,
        "output": 0.0026,
        "cacheRead": 0.025,
        "cacheWrite": 0.025,
        "total": 0.0685
      }
    }
  }
}

See the pi session format docs for full details.

Development

bun install
bun test          # Run tests
bun run dev       # Run from source
bun run build     # Build for distribution
bun run lint      # Lint

License

MIT