pi-model-costs

Per-1M-token pricing in pi's model picker — visible before you switch, so you know what your next prompt will cost.

Works in two modes:

• override (default) — replaces the built-in /model selector with the pricing-aware picker, keeping the stock interaction model: fuzzy filter, ↑/↓ navigation, Tab all/scoped, ctrl+s save-as-default, and keybindings read from your keybindings.json.
• command — leaves /model untouched and registers a new /model-costs command instead (/model-costs <search> opens the picker pre-filtered, /model-costs provider/id switches directly).

Both modes include models from custom providers registered via pi.registerProvider — the picker re-arms after the registry refresh completes, so custom providers and custom models.json entries show up with their pricing too.

The picker shows, per model:

→ sonnet-4-5 [anthropic] $3/$15 · 200k ctx ✓ · default
  $3 in · $15 out · cache $0.3 read / $3.75 write (per 1M tokens)
  … sonnet-4-5 · 200k ctx · 64k max out · reasoning · text+image

Free models show as free; tiered long-context pricing is listed per tier.

Install

pi install npm:@banh-me/pi-model-costs

Alternatives:

# pin a version / install project-only
pi install npm:@banh-me/pi-model-costs@0.1.0
pi install npm:@banh-me/pi-model-costs -l

# from git
pi install git:github.com/banh-me/pi-model-costs

# or try it for one run without installing
pi -e npm:@banh-me/pi-model-costs

Restart pi after install (or run /reload).

Configuration

Options live in the piModelCosts section of pi settings — global ~/.pi/agent/settings.json, or per-project <cwd>/.pi/settings.json (project keys override global):

{
  "piModelCosts": {
    // "override" (default) — replace the built-in /model picker with the
    //                       pricing-aware one
    // "command"             — don't touch /model; register /model-costs instead
    // Aliases accepted: "override" | "replace" | "builtin" | "model" and
    // "command" | "model-costs" | "register" | "add"
    "mode": "override"
  }
}

For one run without editing settings, set PI_MODEL_COSTS_MODE (override or command) in the environment — it wins over settings. Handy with pi -e:

PI_MODEL_COSTS_MODE=command pi -e npm:@banh-me/pi-model-costs

Behavior notes

• Override mode wraps the editor's submit path so it only intercepts /model; every other command and prompt passes through untouched. It chains with other custom editors (e.g. pi-vim) — enabling or disabling another editor at runtime re-wraps cleanly, neither extension clobbers the other.
• Only interactive (tui) mode shows the picker; print/RPC invocations get a notice instead.
• The actual switch still goes through pi's normal setModel path, so API keys resolve exactly as the stock /model would.

How this differs from other model-costs extensions

This package stands on two earlier works — MaurizioFaeddaDev/model-costs and shakthi-sagar/pi-extensions pi-model-costs (see Attribution), and is intentionally a different point on the simplicity axis:

The differences in short:

1. /model itself gets pricing — you keep the one command you already type, with the built-in picker's exact interaction model (fuzzy filter over provider/id name $in/$out, Tab all/scoped, ctrl+s sets defaultProvider/defaultModel in settings.json, message on missing API keys). If you'd rather keep /model stock, mode: "command" gives you /model-costs instead — no editor replacement needed in that mode.
2. Custom-provider friendly — providers added with pi.registerProvider (or custom models.json entries) arrive in the registry asynchronously; the picker listens for the refresh and re-feeds its list, preserving scope, query and cursor.
3. Deliberately simple — no footer status, no cost sorting, no startup UI, no configuration beyond one option. It shows pricing in the picker and that's it.

Attribution

• MaurizioFaeddaDev/model-costs (MIT © 2025 Maurizio Faedda) — the pricing presentation derives from its picker: in/out rates, cache read/write rates, pricing tiers, context window, max output tokens, and the Tab all/scoped toggle.
• shakthi-sagar/pi-extensions — packages/pi-model-costs (MIT) — the idea of showing pricing inside Pi's own /model via an editor-wrapped intercept, and the single-file extension package layout used as reference.

Both were used as references; this implementation is original code.

Development

npm install
npm run typecheck

Runtime dependencies (@earendil-works/pi-ai, @earendil-works/pi-coding-agent, @earendil-works/pi-tui) are host-provided and declared as peer dependencies; only devDependencies are installed for typechecking.

Releases: publish to npm happens automatically from GitHub Actions (workflows/publish.yml) via npm trusted publishing (OIDC) whenever a release is tagged v<package.json version>.

License

MIT