Relay Performance Best Practices

Performance-focused guidance for Relay applications. For correctness, naming, and architectural patterns, see the relay-best-practices skill.

For detailed API documentation, read the relevant page from <llm-docs>/ (available in node_modules/relay-runtime/llm-docs/ after v20.1.1).

One Query Per Screen

Each screen or route should have one (or very few) root queries. Relay coalesces all fragment data needs into a single network request per query. Multiple root queries on the same screen defeat this optimization — the browser makes multiple parallel requests that each carry redundant overhead (HTTP headers, connection setup, response parsing).