What Is Open Spanner?

Open Spanner is a small metering service for usage-based products. It records usage facts from your application and lets you query those facts as aggregate buckets later.

Use it when your product needs answers like:

• How many API requests did org_123 make last month?
• How many tokens were consumed by each model or region?
• Which customers crossed a usage threshold?
• What usage data should be exported into billing or analytics?

Product Model

Open Spanner has three core ideas:

• Meters define what can be measured.
• Usage events record facts against a meter.
• Usage queries aggregate those facts into time buckets.

The dashboard helps people set up and inspect the system. API keys and SDKs connect trusted backend services that create meters, write usage, query buckets, and export data.

What It Is Not

Open Spanner is not a payment processor, invoice generator, entitlement system, or customer identity provider. It gives those systems clean usage data to work with.

The main control-plane surface is HTTP plus generated SDK packages. gRPC is scoped to trusted backend usage ingestion.