Built for AI products

Track AI usage.
Bill it accurately.
Without rebuilding your stack.

UsageBox meters tokens, GPU minutes, agent runtime, and tool calls per customer. Open-source storage engine. Connects to Stripe or your own invoicing.

Start freeView docsSee the source on GitHub →
Idempotent
Ingestion
Immutable
Audit trail
Open source
Storage engine
POST /v1/events
curl -X POST https://api.usagebox.com/v1/events \
-H "Authorization: Bearer $UBX_KEY" \
-d '{
"event_id": "req_8x42jk",
"account_id": "acme-co",
"meter": "llm_tokens_in",
"model": "claude-4.5-sonnet",
"quantity": 12450,
"timestamp": "2026-05-16T18:42:11Z"
}'
 
# Idempotent. Retries are safe.
# Rolls up hourly. Invoiced via Stripe.

Why generic billing breaks on AI workloads

Stripe Billing, Chargebee, Recurly: built for SaaS subscriptions in the 2010s. AI usage is a different shape of problem.

Volume breaks generic billing

Stripe's metered usage assumes thousands of events per customer per month. AI products send millions per day. Generic tools throttle, fail silently, or charge you per-event.

Attribution needs a graph

An agent run is N tool calls + M LLM calls + K memory ops. Each costs different amounts. Generic billing tools can't roll those into a single billable unit without engineering work you keep redoing.

Attacks show up in the bill

A user can manipulate prompts to trigger expensive generations. Without per-user spend ceilings and real-time anomaly detection, the first sign of an attack is your AWS or OpenAI invoice next month.

Built for the way AI products actually meter

Six primitives. Each one designed for the AI billing patterns generic tools fight you on.

Token Metering

Meter LLM input + output tokens per request, per agent, per tenant. Idempotent ingestion handles retries without double-billing.

GPU Minute Pricing

Bill inference time, fine-tuning runtime, or per-job GPU usage. Catalog-driven pricing rules; no code changes to update rates.

Per-Agent Cost Attribution

Track cost for each agent run across N tool calls + M LLM calls + memory ops. Roll up to tenant invoices automatically.

Real-Time Anomaly Detection

Cost-amplification attacks land in your usage data first. Per-user spend ceilings, alerting on token surges, kill-switches.

Hourly Rollups

Raw events feed hourly aggregates. Invoice generation is O(1) per account, not a scan over millions of rows.

Stripe + Manual Invoicing

Plug into Stripe for self-serve. Or generate finance-ready invoices for enterprise contracts. Same metering pipeline.

The storage engine is open source

usagedb is the Rust storage engine UsageBox runs on. Append-only, idempotent, immutable raw event audit trail, hourly rollups for invoice queries. Apache 2.0 on GitHub.

Read the code that produces every invoice line. Fork it. Self-host the ingestion layer while still using UsageBox for the platform side. The right answer to “is your billing math correct” is “read the code yourself.”

pbudzik/usagedb

Or read the architecture overview in our usagedb article, then go deep with the 10-part engine internals series: ingest, dedupe, columnar segments, rollups, the query engine, and how it is tested.

Notes on AI billing

Practical writing on metering patterns, AI cost attribution, and what we learn from production billing systems.

Browse all articles →

June 12, 2026 · 11 min read

OpenAI Filed Too: The $852B IPO, the Price War, and Who Actually Gets the Discount

OpenAI confidentially filed its S-1 June 8 (Goldman/MS/JPM, September window, $730-852B reported) - days after Anthropic - and the WSJ says it is weighing drastic price cuts for the coming war over coding workloads. The buyer analysis: why the threat is credible (the 80% o3 cut precedent), why price wars only pay portable workloads with evals and routing, why unmetered volume eats any discount, what the dual public S-1s will settle in late summer, and the four-week playbook.

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June 12, 2026 · 11 min read

The $1,400 Hour: A PM, 87 Tasks, and the Anatomy of a Runaway Agent Bill

A team reported on r/cursor that asking the agent to tag 87 tasks burned $1,400 in one hour (~$16/task) - and two days later Cursor's CEO refunded it personally. The anatomy of the runaway agent bill: per-item context loading, no effort pricing, an invisible meter; why CEO refunds are weather not climate; why the OpenAI-Anthropic price war (WSJ, both freshly IPO-filed) cannot fix a price-times-volume problem; and the four layers that stop this at $20 (session budgets, per-seat caps, cost-per-task visibility, bulk-job routing).

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June 12, 2026 · 11 min read

Anthropic Filed for a $965B IPO. Here Is What It Means for Your Claude Bill

Anthropic confidentially filed its S-1 on June 1, 2026 after a $65B round at a $965B valuation, with a reported $47B revenue run rate and ~$1.25B/month in contracted compute. For Claude customers the IPO is a pricing-roadmap story: why frontier premiums (Fable 5 at 2x), subscription unbundling (June 15 credit split), and model retirements read as pre-listing margin discipline, what to read in the public prospectus (gross margin, revenue mix, compute footnotes), and the four moves that protect your unit economics either way.

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