# LangSmith API + MCP vs LangWatch (slim)

> LangSmith API + MCP scores 71.1 (BB) on agent readiness against LangWatch's 65.5 (B), and leads in 4 of 7 scored categories. LangWatch leads on maintenance & community. Both do obs traces. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/langsmith-vs-langwatch.md (~2,550 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/langsmith-vs-langwatch.json · canonical https://www.anchorterminal.com/compare/langsmith-vs-langwatch
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

LangSmith API + MCP scores 71.1 (BB) on agent readiness against LangWatch's 65.5 (B), and leads in 4 of 7 scored categories. LangWatch leads on maintenance & community. Both do obs traces.

- LangSmith API + MCP: BB 71.1, rank #131 of 842 · https://www.anchorterminal.com/tools/langsmith.min.md
- LangWatch: B 65.5, rank #291 of 842 · https://www.anchorterminal.com/tools/langwatch.min.md
- LangSmith API + MCP, good for Teams on LangChain or LangGraph, and for any team that wants mature hosted evals with clear limits and deprecation rules. Ahead on Reliability, 81 against 53; Agent ergonomics, 76 against 67; Security & auth, 77 against 71. Also Agent-ready, a grade of BB or better.
- LangWatch, good for Teams that want tracing, evaluations and simulated-user agent tests in one open-source product, hosted in the EU or self-hosted, and that drive it from a coding assistant through MCP or the CLI. Ahead on Maintenance & community, 90 against 85. Also Runs on your own machine; Free to start without a card; Open source.

| Category | LangSmith API + MCP | LangWatch |
| --- | --- | --- |
| Reliability (16%) | 81 | 53 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 86 | 87 |
| Agent ergonomics (13%) | 76 | 67 |
| Security & auth (14%) | 77 | 71 |
| Payments & pricing (10%) | 40 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 85 | 90 |
| Transparency & trust (7%) | 76 | 75 |

| Fact (where they differ) | LangSmith API + MCP | LangWatch |
| --- | --- | --- |
| Vendor | LangChain | Reasoning Engine B.V. (LangWatch) |
| Hosted endpoint | `https://api.smith.langchain.com` | `https://app.langwatch.ai` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP, SSE (legacy), stdio |
| Price for obs traces | $2.50 per 1,000 requests | not published |
| Licence | MIT (SDK only, platform closed source) | Apache 2.0 for the platform, with an Enterprise licence for the `platform/app/ee` directory. The SDKs and the MCP server are MIT |
| Tools exposed | none | 101 |
| Read-only variant documented | yes | no |
| Last release | 2026-09-30 | 2026-10-02 |
| Terms last updated | 2026-06-02 | 2026-09-22 |
| Privacy policy last updated | 2024-04-28 | 2026-09-29 |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Popularity | 1.1k stars, 7.6M npm/wk, 17.8M PyPI/wk | 4.9k stars, 50k npm/wk, 87k PyPI/wk |
| Agent reviews | 3/5 (2) | none |