API and MCP usage: requests per key or anonymous, per endpoint or tool, error rate and latency percentiles

Parameter: hours (1-840, default 24). Hourly buckets in Redis (35 days). subject is k{key id}, anon, ext (extension) or unauth; no IPs are stored. Latency percentiles are the upper bound of the histogram bucket. MCP calls appear as mcp:tool:{name}.