@jovan158/vantage/dist/meter.js

See and control what your coding agent does

// Running meter: aggregates per-request usage events into session totals and a
// short-window output-token rate, and formats a compact status line.
//
// Honesty rule (CONCEPT.md §6a): tokens are always exact; the dollar figure is
// an estimate and is labelled as such — under a subscription plan there is no
// real per-token cost, only quota consumption.
import { formatRateLimit } from "./ratelimit.js";
import { formatCost } from "./pricing.js";
export class Meter {
    totals = {
        requests: 0,
        input: 0,
        output: 0,
        cacheRead: 0,
        cacheWrite: 0,
        costUsd: 0,
        unpriced: 0,
        unpricedModels: [],
    };
    // (timestampMs, cumulativeOutput) samples for a rolling rate.
    samples = [];
    windowMs = 60_000;
    rateLimit = null;
    setRateLimit(snapshot) {
        this.rateLimit = snapshot;
    }
    rateLimitLine(nowMs = Date.now()) {
        return this.rateLimit ? formatRateLimit(this.rateLimit, nowMs) : null;
    }
    add(e, nowMs = Date.now()) {
        this.totals.requests += 1;
        this.totals.input += e.in;
        this.totals.output += e.out;
        this.totals.cacheRead += e.cache_read;
        this.totals.cacheWrite += e.cache_write;
        if (e.cost_usd === null) {
            this.totals.unpriced += 1;
            const model = e.model ?? "unknown model";
            if (!this.totals.unpricedModels.includes(model))
                this.totals.unpricedModels.push(model);
        }
        else {
            this.totals.costUsd += e.cost_usd;
        }
        this.samples.push([nowMs, this.totals.output]);
        const cutoff = nowMs - this.windowMs;
        while (this.samples.length > 1 && this.samples[0][0] < cutoff) {
            this.samples.shift();
        }
    }
    snapshot() {
        return { ...this.totals, unpricedModels: [...this.totals.unpricedModels] };
    }
    // Output tokens per minute over the trailing window.
    outputTokensPerMin(nowMs = Date.now()) {
        if (this.samples.length < 2)
            return 0;
        const [t0, o0] = this.samples[0];
        const spanMs = Math.max(1, nowMs - t0);
        const deltaOut = this.totals.output - o0;
        return (deltaOut / spanMs) * 60_000;
    }
    // Compact one-line status, e.g.:
    //   Σ in 2.0k · out 174 · cache 512 · ~$0.009 (est.) · 348 out/min
    statusLine(nowMs = Date.now()) {
        const t = this.totals;
        const rate = Math.round(this.outputTokensPerMin(nowMs));
        const parts = [
            `Σ in ${fmt(t.input)}`,
            `out ${fmt(t.output)}`,
            // Cache writes cost ~1.25x input, so hiding them makes the cost look
            // inexplicable. Show them whenever they occur.
            t.cacheWrite > 0
                ? `cache ${fmt(t.cacheRead)}r/${fmt(t.cacheWrite)}w`
                : `cache ${fmt(t.cacheRead)}`,
            formatCost(t.costUsd, t.unpriced, t.requests),
        ];
        if (rate > 0)
            parts.push(`${fmt(rate)} out/min`);
        return parts.join(" · ");
    }
}
function fmt(n) {
    if (n < 1000)
        return String(Math.round(n));
    if (n < 1_000_000)
        return (n / 1000).toFixed(n < 10_000 ? 1 : 0) + "k";
    return (n / 1_000_000).toFixed(1) + "M";
}