Brian Munene Mwirigi

Posted on Feb 1

I Got Tired of Burning Money on AI APIS - Built a CLI Tool to Fix It

#ai #cli #money #token

I checked my OpenAI billing last month. $217. I had no idea where it went.

The solution: I built aitoken-cli. Now I track every cent.

The result: Reduced spending to $89/month. 59% savings.

The Hidden Cost of AI Development

If you're a developer in 2026, you're using AI APIs. GPT-4, Claude, Gemini they're essential tools.

The costs creep up silently.

My Wake-Up Call

December 2025:

Week 1: $12 (seems fine)
Week 2: $28 (okay, working on a project)
Week 3: $51 (wait, what?)
Week 4: $126 (WTF?!)

Total: $217

I was a broke CS student burning $217/month on AI. Something had to change.

Why Existing Solutions Failed Me

You'd think tracking API costs is solved, right? Wrong.

OpenAI Dashboard

Shows totals only
No breakdown by task
No comparison across providers
Have to log in every time

Spreadsheets

Manual entry (I forgot constantly)
No automatic cost calculation
Boring, never kept it updated

Existing npm packages

Too complex (need servers, databases)
Privacy concerns (send data to cloud)
Not comprehensive (OpenAI only)

The gap: I needed something local, fast, and comprehensive.

Building aitoken-cli

Friday night, 9 PM: Just got my $217 bill. Angry.

Friday night, 11 PM: Sketched the design.

Saturday, 3 AM: First version working. Tracking OpenAI only.

Saturday, 9 AM: Added Anthropic, Google, Azure, Cohere.

Saturday, 2 PM: Published to npm.

Total time: 6 hours.

How It Works

Track Usage in Seconds

# Track a GPT-4 call
at add -p openai -m gpt-4o -i 1500 -o 800

# Output: ✓ Added usage #47 - openai/gpt-4o - $0.0118

View Your Stats

at stats

# Output:
# Total Usage: $34.56 (245,890 tokens)
# 
# By Provider:
# OpenAI:    $21.34 (150,000 tokens)
# Anthropic: $11.22 (85,000 tokens)
# Google:    $2.00  (10,890 tokens)

Today's Spending

at today

# Output:
# Today's Usage: $4.23 (15,670 tokens)
# 
# Latest entries:
# 10:15 AM - gpt-4o     - $1.52 (5,000 tokens)
# 11:30 AM - claude-3.5 - $2.71 (10,670 tokens)

Integrate with Your Code

// After an OpenAI call
const response = await openai.chat.completions.create({
  model: "gpt-4o",
  messages: messages
});

// Track it
const { prompt_tokens, completion_tokens } = response.usage;
exec(`at add -p openai -m gpt-4o -i ${prompt_tokens} -o ${completion_tokens}`);

The Impact: Real Savings

Before aitoken-cli (December 2025):

Monthly cost: $217
Awareness: Zero
Optimization: None

After aitoken-cli (January 2026):

Monthly cost: $89
Awareness: 100%
Optimization: Strategic model switching

Savings: $128/month (59% reduction)

How I Optimized My AI Spending

Discovery 1: GPT-4 for Everything Was Wasteful

Before: Used GPT-4 for simple tasks like string formatting

Fix: Use GPT-3.5 Turbo for simple tasks

Savings: $40/month

Discovery 2: Long Prompts Every Time

Before: Sent full system prompts with every request

Fix: Cache system prompts, send only deltas

Savings: $30/month

Discovery 3: Claude is Often Better AND Cheaper

Before: Default to GPT-4 for everything

Fix: Use Claude 3.5 Sonnet for coding tasks

Savings: $35/month

Discovery 4: Redundant API Calls

Before: Making duplicate calls without noticing

Fix: Added request deduplication

Savings: $23/month

None of this was possible without tracking.

Technical Details

Tech Stack

TypeScript - Type safety for pricing data
Commander.js - CLI framework
SQLite (better-sqlite3) - Local database
Chalk - Pretty terminal output

Database Schema

CREATE TABLE usage (
  id INTEGER PRIMARY KEY,
  provider TEXT NOT NULL,
  model TEXT NOT NULL,
  prompt_tokens INTEGER NOT NULL,
  completion_tokens INTEGER NOT NULL,
  total_tokens INTEGER NOT NULL,
  cost REAL NOT NULL,
  timestamp TEXT NOT NULL,
  notes TEXT
);

Simple. Effective. Local.

Privacy: Why Local Matters

aitoken-cli stores everything in ~/.aitoken/usage.db.

No cloud. No API. No tracking.

Why?

Your usage patterns are private - Nobody knows what you're building
Works offline - No internet? Still tracks
Fast - No network latency
Free forever - No subscription costs
You own your data - Export anytime

Installation

npm install -g aitoken-cli

Quick Start

# Track your first API call
at add -p openai -m gpt-4o -i 1000 -o 500

# View your stats
at stats

# See today's usage
at today

# List all providers and models
at models