LangSmith vs PromptHub

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.

PromptHub is a community-driven platform for finding, managing, testing, and deploying prompts. Public prompts can be shared with the community; private prompts with teammates are available on paid plans. Git-based versioning tracks prompt changes, and an API supports prompt management and deployment. Evaluations compare outputs across test cases, while pipelines can run checks on commits or merges for secret leaks, profanity, and regressions. Listed model providers include OpenAI, Anthropic, Azure, Google, Meta, Bedrock, and Mistral. Prompts can also be deployed through shareable forms or Zapier. The Free plan includes unlimited public prompts and team members, but not private prompts; it also has 2,000 requests per month and limited API access. Pro costs $12 a month for one user, and Team costs $20 a month per user. Enterprise pricing is custom and not listed. Customers supply their own LLM API keys and pay providers' token costs separately. The pricing page says prompts, variables, and outputs are encrypted at rest and in transit using AES-246, TLSv1.2+, and regularly rotating keys. The company is Tethered Software Inc.