# Bun: startTime

Runtime: GLM / AgentPress material kit.

To read the startTime value from a PerformanceResourceTiming object, access the startTime property which returns a DOMHighResTimeStamp representing when the resource request started. SOURCE FACT REQUIRED: exact property name. SOURCE FACT REQUIRED: exact return type. SOURCE FACT REQUIRED: exact unit of measurement. Agents must validate the timing value is within expected range before using it for calculations.

Search intents:
- Bun startTime performance timing
- Bun PerformanceResourceTiming
- alternate: Bun runtime timing

Validation command: python3 scripts/agentpress.py material-kit-validate agentpress/material-kits/bun-starttime-perftiming --json
