LangSmith vs ZenMux
LangSmith
langchain.comZenMux
zenmux.aiSide by side
| Figure | LangSmith | ZenMux |
|---|---|---|
| Price from | $39/mo | $20/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 3 | 4 |
| Spec score · LLM Gateway Software | 9.2 (#1) | 7.5 (#27) |
| Spec score · LLM gateways | 9.3 (#2) | 7.8 (#23) |
| Headquarters | San Francisco, California, United States | 11 Collyer Quay, #05-06C, The Arcade, Singapore 049317 |
| Integrations | Documented integrations cover OpenAI, Anthropic, Bedrock, Gemini, Mistral, LiteLLM, OpenTelemetry, CrewAI, Vercel AI SDK, PydanticAI, AutoGen and many other frameworks and providers. | The subscription guide lists integrations for Claude Code, CodeX, Cline, VS Code Copilot, OpenCode, Cherry Studio, Obsidian, Dify, and Open WebUI. |
| Observability | Its observability features include agent tracing, cost tracking, online LLM-as-judge and code evaluations, trajectory monitoring, and webhook or PagerDuty alerts. | The platform provides API request logs and analytics for costs, usage, and performance. |
| Support | The Developer plan includes community support, and the Enterprise plan lists a support SLA. | ZenMux lists technical support by email and says it typically responds within 24 hours. |
Plans
In their own words
LangSmith
LangSmith is a commercial agent-engineering platform for building, evaluating, deploying, monitoring, and improving AI agents. It supports offline evaluations on curated datasets and real-time scoring of production interactions. Evaluation methods include human review, heuristic checks, LLM-as-judge evaluators, pairwise comparisons, and custom Python or TypeScript evaluators. Annotation queues route runs to subject-matter experts for feedback that can calibrate evaluations, improve prompts, or augment datasets. The Playground compares prompt versions or model providers, and LangSmith chat can auto-improve prompts. Observability includes agent and retrieval tracing, token and general cost tracking, trajectory monitoring, online evaluations, and webhook or PagerDuty alerts. Traces can arrive through SDKs or an API from LangGraph, custom Python, or other stacks; SDKs are listed for Python, TypeScript, Go, and Java. Hosting ranges from cloud to hybrid and self-hosted Enterprise options. The Developer plan costs nothing, Plus costs $39 a month, and Enterprise pricing is custom.