Vellum
LLM dev platform — prompt versioning, evals, monitoring in one tool.
Visit Vellum From $500/mo
What is Vellum?
Vellum is the developer platform for building production LLM apps. Prompt management with versioning, A/B testing, evals against your own datasets, production monitoring. Used by teams shipping AI features at companies like Drata, Anrok, and Replicate.
Key features
- Prompt versioning + A/B testing
- Eval suites with your data
- Multi-model routing
- Production observability
- Prompt collaboration (PMs + engineers)
- API + SDK
Pros
- Genuinely replaces 4-5 separate tools
- Strong evals workflow
- PMs can collaborate without code
Cons
- Pricey for early-stage startups
- Some overlap with LangSmith
- Learning curve in week 1
Best for
Teams shipping LLM features to productionPMs working with engineers on promptsCompanies running A/B tests across modelsSeries A-C startups
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