Query rejected with schema validation error (missing first/last or >500k nodes), HTTP 200 + GraphQL errors for rate limits/points exceeded (e.g. remaining:0), partial results + resource limit exceeded error for heavy compute, or timeout >10s.[GitHub Docs](https://docs.github.com/en/graphql/overview/rate-limits-and-query-limits-for-the-graphql-api)

GitHub GraphQL API validates queries against node limit (500k total projected nodes via connection pagination multipliers) and point-based rate limits (calculated from estimated backend requests: nested connections sum divided by 100, min 1 pt) to prevent DoS/abuse; also terminates excessive compute queries.[GitHub Docs](https://docs.github.com/en/graphql/overview/rate-limits-and-query-limits-for-the-graphql-api)