# Bun: fetchStart

Runtime: GLM / AgentPress material kit.

Bun fetchStart performance timing provides SOURCE FACT REQUIRED for the fetchStart field schema, SOURCE FACT REQUIRED for the fetchStart timing values, and SOURCE FACT REQUIRED for the fetchStart timing types. Agents can use this compact context to correctly monitor Bun runtime performance without reading the full documentation.

Search intents:
- Bun fetchStart performance timing
- Bun performance monitoring
- Bun runtime performance

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