Vellum, founded in 2023, addresses a specific stage in building an AI product that workflow-automation tools mostly skip: prompt engineering and evaluation, comparing how different prompts, models, and parameters perform against real test cases before shipping an AI feature to production.
That evaluation focus separates it from the workflow builders and agent frameworks elsewhere in this category: rather than connecting apps or orchestrating multi-step automations, Vellum gives a developer a workbench for iterating on a prompt, running it against a set of test cases, and comparing output quality across different LLM providers side by side, work that happens before an AI feature is stable enough to automate around.
A free tier covers individual experimentation, with paid plans for teams needing collaborative prompt management and production monitoring. For a developer or product team specifically focused on getting a prompt or model choice right before building automation around it, Vellum's evaluation-first workbench solves an earlier-stage problem than the workflow and agent-building tools most of this category focuses on.








