OpenAI API — Production Agent Use Review

Pros

• –Best-in-class function calling reliability — structured outputs via JSON mode rarely hallucinates field names
• –Parallel tool calls in a single response reduces round-trips significantly
• –Streaming is stable and well-documented; token-level streaming works reliably
• –Assistants API thread management simplifies stateful multi-turn conversations

Cons

• –Rate limits on Tier 1 accounts are aggressive — 10k RPM is hit fast in multi-agent fan-out
• –Latency spikes during peak hours (8am–2pm US EST) — p99 can reach 8s on gpt-4o
• –No native support for custom system-level memory injection without prompt engineering
• –Batch API has 24h turnaround — not suitable for near-real-time pipelines