Is my API key secure?

Yes. Keys are encrypted at rest using AES-256-GCM and never exposed in any response, log, or UI after the initial save. We store minimum-scope keys needed to read usage data — read-only access only. You can revoke any key from Costline at any time.

Works with OpenAI · Anthropic · Google · AWS Bedrock

See exactly which AI agent is burning your budget

Per-agent cost tracking for AI teams. Real-time spend attribution, runaway detection, and hard budget enforcement — before waste happens.

Start Tracking Free → See How It Works

Free for 2 providers · No credit card · Takes 30 seconds

Agent Fleet Spend Last 30 days

Total Spend

$12,847

↓ 34% vs. last month

Savings Found

$6,412

Optimized automatically

OpenAI

$4,230

Anthropic

$3,105

Twilio

$2,890

AWS

$2,622

Market validation — The developer consensus

Live product — free tier ready now — track your first agent in 2 minutes Start Free →

See It In Action

This is what your dashboard looks like.

Real data, per-agent breakdown, zero guesswork. Here's what you'll see the moment you connect your first API key.

Total Spend

$847.12

↓ 12.3% vs last week

API Calls

14,829

↑ 8.1% (good)

Active Agents

2 new today

Avg Cost/Call

$0.057

↑ 3.2% (watch)

Per-Agent Cost Breakdown

Agent	Provider	Daily Cost	Calls	Status
⚙ Support Agent gpt-4o	● OpenAI	$12.47	1,204	● Healthy
✎ Research Agent claude-3.5-sonnet	● Anthropic	$8.93	892	● Healthy
☆ Code Review Bot gpt-4o-mini	● OpenAI	$4.18	3,421	● Healthy
⚡ Data Pipeline Agent claude-3.5-sonnet	● Anthropic	$18.74	447	⚠ Over budget
↺ Email Writer gpt-4o	● OpenAI	$47.83	892	⚠ Loop detected

This is your fleet, live. Every agent, every provider, every cost.

Start tracking free — no credit card required →

2 providers · unlimited agents · set up in 2 minutes

Features

Know exactly which agent burned the budget.

From the first API call to the runaway loop — per-agent cost visibility that stops blind optimization.

⚡

Per-Agent Cost Attribution

Know exactly which agent burned the budget, from the first call to the runaway loop. Multi-agent hierarchies? Costline breaks down spend by agent, model, provider, and task type.

🔍

Hard Budget Enforcement

Real-time cost caps, not post-execution dashboards. Stop runaway spend before it starts. Set hard limits per agent, per team, per provider — with automatic enforcement.

📊

Multi-Tenant Chargeback

Allocate costs by customer, feature, or team. Bill them accurately. No guesswork. No spreadsheets. Costline tracks spend isolation so you know exactly what each user owes.

🤖

Runaway Detection

Automatic loop detection stops repeated tool calls before they cascade. Pattern-based anomaly detection catches cost spikes in minutes, not hours.

How It Works

Three steps to controlled AI spend

Connect Your Providers

Plug in your OpenAI, Anthropic, AWS, and other API keys. Costline starts ingesting usage data in minutes.

Map Your Agent Fleet

Tag agents by function, team, or priority. Costline learns your fleet's spending patterns and identifies optimization targets.

Watch Savings Grow

Costline autonomously routes, caches, and optimizes. Average customers cut agent API spend by 40% in the first month.

Cost Calculator

How much is your agent fleet costing you?

Dial in your fleet size and see the real numbers — including what you're likely wasting without per-agent tracking.

Number of AI agents 5

1 agent 100 agents

Executions per agent / day 10

1/day 50/day

Avg. cost per execution

▼

Your Estimate

Monthly agent spend

$450

⚠️ Without per-agent tracking, teams overspend by 15–40% — mostly from runaway agents and untracked model drift.

Potential monthly savings

at ~25% waste reduction

$113

Track your real agent spend — Start Free →

No credit card · free tier · 2-minute setup

FAQ

Common questions

Everything you need to know before you connect your first key.

OpenAI and Anthropic are fully supported today — connect your API keys and start seeing real spend data within minutes. AWS Bedrock, Azure OpenAI, and Google Vertex AI are on the roadmap. If your provider isn't listed, reach out and we'll prioritize it.

You tag each agent in your fleet with a name or ID when you connect your API keys. Costline then attributes every API call to the originating agent — no proxying required. You get a live dashboard showing cost, tokens, and usage trends broken down by agent, model, and provider.

Under 2 minutes. Create an account, paste your API keys, and Costline immediately starts pulling usage data. No SDK to install, no proxy to route traffic through, no code changes required.

Yes. Keys are encrypted at rest using AES-256-GCM and never exposed in any response, log, or UI after the initial save. We store the minimum-scope keys needed to read usage data — read-only access only. You can revoke any key from Costline at any time.

Costline is free to start — connect up to 2 providers and track unlimited agents on the free tier. Paid plans unlock real-time anomaly alerts, smart model routing, and autonomous optimization. See the full breakdown on the pricing page.

No. Costline reads usage data directly from provider APIs using your existing keys — it sits entirely outside your application stack. There's no SDK to install, no proxy in the critical path, and zero risk of adding latency to your agents. Your code stays exactly as it is.

Live product — free tier available now

Stop overpaying for AI.

Connect your API keys and see exactly which agents are burning money. Free to start, no credit card, live in 2 minutes.

2 providers · unlimited agents · no credit card

Comparing tools? Costline vs Portkey vs Helicone vs LangSmith →