# llm-api-benchmark-tool Project Rules & Patterns

1.  **TDD is MANDATORY.** Write tests first (`test/` dir).
2.  **Client Implementation:** Use `FastHTTPClient` (`pkg/client/fasthttp.go`).
3.  `FastHTTPClient` uses `fasthttp` for `Do` (non-stream) and `net/http` for `Stream` (SSE).
4.  Streaming stability relies on the internal `net/http` usage.
5.  Configuration via `config/config.yaml` drives benchmark parameters.
6.  Core metrics defined in `stats.RequestResult` (`pkg/stats/collector.go`).
7.  Concurrency managed via goroutine pool in `pkg/concurrency/manager.go`.
8.  Use `tiktoken-go/tokenizer` for token operations.
9.  Record results (`statsCollector.RecordResult`) immediately after request completion in `runWorker`.
10. Prefer fixing core functionality/bugs before large refactors.