OpenAI API vs LangSmith

OpenAI API

LangSmith

OpenAI API · 12 features

• Assistants API — Stateful assistants with tools, threads, file search.
• Batch API — 50% discount for async processing within 24h.
• Chat Completions API — Classic /v1/chat/completions endpoint.
• Files API — Upload docs for retrieval, fine-tuning, batch.
• Fine-Tuning — Supervised + DPO fine-tuning for GPT-4o, GPT-4.1, GPT-4o-mini.
• Function Calling — JSON-schema tool calling; parallel calls supported.
• Moderation — Safety classifier API (free).
• Prompt Caching — Auto-cache repeated prefixes; 50% cheaper cached hits.
• Realtime API — WebSocket streaming voice + text with low latency.
• Responses API — Stateful conversational API.
• Structured Outputs — Enforced JSON schema compliance.
• Vision — Image input for GPT models.

LangSmith · 14 features

• Alerts — Threshold alerts on latency, cost, eval metrics.
• Annotation Queues — Human-review workflows for trace quality rating.
• Custom Dashboards — Aggregate metrics dashboards per project/tag.
• Datasets — Collect examples → use as eval sets or training data.
• Evaluations — LLM-as-judge, embedding similarity, custom Python evaluators, offline batch eval…
• LangChain Integration — Auto-trace any LangChain/LangGraph run with env var.
• LangGraph Integration — First-class trace + eval for LangGraph agents.
• LLM Tracing — Automatic trace every LLM call + tool call + chain step.
• OpenTelemetry Export — Export traces as OTLP to Datadog/Honeycomb/etc.
• Playground — Test prompts + models inline before deploying.
• Prompt Canvas — Visual prompt editor with live test + eval.
• Prompt Hub — Public + private prompt library with versioning.
• Self-Hosted (Enterprise) — Docker + k8s deployment in your infra.
• Threads + Sessions — Group traces into conversational sessions.