V 
Vellum
Development platform for prompt engineering, evaluation and deploying AI workflows.
NOT REALLY
why this verdict
Keep paying — OpenAI has not replaced it
OpenAI's version overlaps, but does not finish the dev tools job, so this one still earns its $500/mo.
- A named launch, not a vibe named, unlinked
- Coding agents making it trivial to build LLM pipelines in code rather than a visual tool. OpenAI, August 5, 2025 — no announcement link recorded yet.
- How much of the job it covers not the job editorial call
- Parts of it. The job still needs the tool to get finished.
- Is there a free way to do it? paid only
- 3 replacements listed, all paid.
- What the call is worth $6,000/yr
- $500/mo at the entry paid tier — $6,000 a year per seat.
Reason composed from the fields above missing: announcement linked missing: free replacement listed recorded: two or more escape hatches
- Threatened by
- OpenAI
- Since
- August 5, 2025
- List price
- $500/mo
- Per year
- $6,000
The backstory
Vellum gives product and engineering teams a shared surface for building LLM features: version prompts, run evaluations against test banks, compare models and deploy behind an API without redeploying the app. The obvious objection is that engineers can write this in code, faster than ever. The people buying it usually are not engineers, and the collaboration between a domain expert who knows what good output looks like and the engineer who ships it is the workflow being sold.
