Retrieve a customer's usage summary
What a usage meter shows: for each allowance window, how much was granted, used and held, the share used and when it resets, then the balance pools, the next credits to expire, and the money value of this period’s spend. It is read from the ledger, so it works for every customer, with or without allowances: a customer on a plan with no allowances has one window for the plan period and one pool. Use it to draw a meter. Don’t use it to decide whether work may start, because lists and summaries can lag by a few seconds and check() is the authority. percent_used is a decimal from 0 to 1.
Authentication
A secret key (rl_sk_test_..., rl_sk_live_...) or a restricted key with limited scopes (rl_rk_test_..., rl_rk_live_...). A restricted key can carry agent: true and an expires_at, and is what a coding agent should hold. Keys end in a checksum so secret scanners can recognize them. People create, roll and revoke keys in the dashboard; GET /v1/api_keys lists them, masked.
Path parameters
The customer ID (cus_...).
Query parameters
The subscription (sub_...). Defaults to the customer’s active one.
The credit type (ID or key). Defaults to the plan’s.
Read the windows a per_member allowance keeps for this member. Without it, those windows are left out.