Vellum AI (vellum)

Vellum AI is an LLM development platform that helps product and engineering teams build, evaluate, deploy, and monitor LLM-powered applications. The platform centers on prompt engineering, a visual Workflows builder for agentic and multi-step pipelines, evaluation suites with dataset management, retrieval-augmented generation, and production observability with logs, traces, and metrics. Target customers are AI product teams at startups and enterprises that need version control, collaboration, and vendor-neutral access across OpenAI, Anthropic, Google, Mistral, and open models. Vellum exposes a REST API plus Python and TypeScript SDKs, runs in cloud and self-hosted deployments, and offers tiered pricing for Pro/Business/Enterprise. Note: as of 2026 the vellum.ai marketing surface has been refocused on a personal AI assistant product; the developer platform documented here remains the LLM application stack.

APIs.json: https://raw.githubusercontent.com/api-evangelist/vellum/refs/heads/main/apis.yml

Scope

• Type: Index
• Position: Provider
• Access: 3rd-Party

Tags

• LLM Platform
• Prompt Engineering
• Workflows
• Evaluations
• LLM Ops
• RAG
• Observability
• Datasets
• Deployments
• Multi-Provider
• Agent Builder
• Self-Hosted

Timestamps

• Created: 2026-05-23
• Modified: 2026-05-23

APIs

Vellum LLM Platform API

The Vellum REST API exposes prompts, workflows, evaluations, datasets, document indexes, deployments, and execution endpoints so developers can run versioned LLM pipelines from their own backends and capture logs and metrics for production monitoring.

• Human URL: https://docs.vellum.ai
• Base URL: https://api.vellum.ai

Tags

• Prompts
• Workflows
• Evaluations
• Datasets
• Documents
• Deployments
• Executions
• Monitoring

Properties

• Documentation
• API Reference
• Getting Started
• Sign Up
• SDK
• SDK
• GitHub Organization
• Pricing
• Blog
• Postman Collection — Postman Collection 2.1
• Open Collection — Open Collection 1.0

Common Properties

• Website
• Documentation
• Blog
• GitHub Organization
• Pricing
• Sign Up
• Login
• Terms of Service
• Privacy Policy
• Twitter
• LinkedIn
• L L Ms Txt

Maintainers

FN: Kin Lane Email: kin@apievangelist.com