Postman vs LangSmith

Postman

LangSmith

Postman · 17 features

• API Documentation — Public + private docs from collections.
• API Versioning — Manage multiple API versions.
• Collection Runner — Run N iterations with data.
• Collections — Saved request groups + runners.
• Desktop App — Native Mac/Win/Linux.
• Environments — Per-env variables.
• Flows (low-code) — Visual workflow builder.
• Governance — API design rules enforcement.
• Mock Servers — Auto-generated mocks.
• Monitors — Scheduled collection runs + alerts.
• Newman CLI — CI/CD collection runner.
• Postman AI — Generate tests + docs with AI.
• Pre-request / Test Scripts — JS scripts + assertions.
• Public API Network — Discoverable APIs marketplace.
• Request Builder — GUI for any HTTP request.
• Request History — Per-user request log.
• VS Code Extension — Requests inside VS Code.

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.