Fusebox

Fusebox is an OpenAI API spend tracking tool that alerts users via email when reaching budget limits.

Fusebox is a spend-ceiling alert tool designed for solo OpenAI API users to prevent unexpected high bills from retry loops or leaked keys. Users set a monthly dollar limit and receive email notifications when usage reaches 50, 80, and 100 percent of that ceiling. Setup takes two minutes and requires filling out three fields. The service uses a read-only OpenAI API key created with only the api.usage.read scope. It supports unlimited months of tracking and provides early warnings before budgets are completely exhausted.

Fusebox at a glance

Best for: Software engineer, Founder
Runs on: Web
Pricing: Free
Released: October 2026
Category: AI productivity tool
Website: fusebox.sifatsrk.workers.dev

Key features

Monthly spend ceiling configuration
Email alerts at 50 percent usage
Email alerts at 80 percent usage
Email notifications at 100 percent usage
Read-only key validation
Two-minute setup process
Unlimited months tracking

Use it for

Track OpenAI API spending limits
Receive budget alerts for side projects
Prevent unexpected high API bills

Alternatives to Fusebox

CostGoat — Monitor AI and cloud spending in real-time to prevent unexpected bills.
Sign in — Tracks exact AI spend per provider, key, and person to match invoices.
GenOffice — Free, open-source desktop office suite with built-in AI file editing.
ClickUp — One app for projects, docs and chat, with AI that knows the work
Postbox — Deploys entirely to your own Cloudflare account for private email management.
OpenUsage — Monitors AI usage limits locally to prevent service interruptions.
Inbox Zero — It organizes your inbox automatically and drafts replies in your voice.
Google Workspace CLI — Dynamically builds commands from Google's Discovery Service with JSON output.
FiscaLLM — Tracks per-user AI costs alongside revenue to identify profitable users.
Qovilio — Tracks all subscriptions and sends reminders before renewals.
Koi — Dictates offline in 100 languages with an all-in-one Mac tool.
Emilio — Sorts priority emails and drafts replies in your tone.

All Fusebox alternatives