UsageBox records billing-grade usage events, deduplicates retries, handles late events, and produces explainable monthly rollups for the biller you already use.
The difficult part is not drawing an invoice. It is preserving a trustworthy quantity through retries, delays, model changes, and billing-vendor changes.
Collectors and application servers retry. A billing-grade meter has to make at-least-once delivery safe rather than turning network behavior into extra usage.
Queues stall, workers reconnect, and batch jobs report after the fact. Event time and ingest time are different facts, and billing needs to preserve both.
Payment and billing vendors change. Keeping raw usage and rollups in an independent layer lets you replace downstream billing without re-instrumenting the product.
Same ingestion contract, different buyer jobs. These pages show how the usage layer fits AI cost, MCP, Stripe and general API metering without pretending one billing model fits all of them.
UsageBox deliberately stops before monetary rating and invoicing. Its job is to make the quantity feeding those systems trustworthy.
Send usage with an Idempotency-Key and retry safely. UsageBox scopes deduplication to your account so transport retries do not become usage.
Meter tokens, API calls, jobs, bytes, seats, or any numeric or unique signal using sum, count, max, and unique-count aggregation.
Backdated and out-of-order events fold into the period where they happened instead of whichever month the collector finally delivered them.
Keep the event that produced each aggregate so usage disputes can be investigated from source data instead of an opaque invoice total.
Read compact per-subscription, per-item, per-meter, per-charge quantities without rescanning every raw event for normal billing workflows.
UsageBox stops at trustworthy quantities. Feed those rollups to Stripe, Lago, your ERP, or your own invoicing code without moving the meter.
usagedb is the Apache-2.0 Rust storage engine being developed for UsageBox. Production UsageBox currently keeps Firestore authoritative while usagedb runs as a shadow path until equivalence and recovery requirements are proven.
Read the engine as it develops, fork it, and follow the design decisions around ingestion, deduplication and rollups. The production boundary is intentionally explicit: usagedb is not yet the authoritative UsageBox store.
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.
Practical writing on metering patterns, AI cost attribution, and what we learn from production billing systems.
October 10, 2026 · 9 min read
Gemini 3.8 Flash is free on the Gemini API Free Tier and costs $0.75 input and $3.75 output per 1M tokens through December 31, 2026, doubling to $1.50 and $7.50 on January 1, 2027. Batch, Flex and Priority prices, free tier rate limits, spend limits, and cost examples.
Read →October 10, 2026 · 8 min read
Gemini CLI limits by sign-in method as of October 2026: 1,000 requests a day with a Google account, 250 a day (Flash only) with an unpaid API key, 1,500 to 2,000 on paid plans. What counts as a request, which plans are not supported, and what pay-as-you-go costs.
Read →October 10, 2026 · 9 min read
OpenAI Codex pricing as of October 2026: Free, Go $8, Plus $20, Pro from $100, Business $20 per user, and API key billing. Local messages per five hours by model, Fast and Ultrafast multipliers, credit rates per 1M tokens, and the GPT-5.5 retirement on October 14.
Read →Free tier. No credit card. Meter first; choose your biller separately.