Vellum

by Vellum AI

Cloud Free Tier paid API Available

LLM application platform with prompt management, evaluation, and deployment workflows for production AI features. Vellum is an LLM application development platform founded in 2023 in San Francisco. The product targets engineering teams that need versioned prompts, evaluation pipelines, and deployment infrastructure for shipping AI features into production applications.

Performance Scores

8.4

1 ranking evaluated

Score range: 8.4 – 8.4

Key Facts

Key facts about Vellum
AttributeValueAs ofSource
PricingPro plan approximately $500/month, Developer tier free, Enterprise customApr 2026Vellum
CapabilitiesPrompt IDE, Evaluations, Workflows, Deployments, RAG indexes (5 modules)Apr 2026Vellum docs
Founded2023Apr 2026Y Combinator
Key DifferentiatorY Combinator W23 alumnus focused on prompt evaluation and regression testing for production LLM appsApr 2026Vellum

Strengths

  • Built-in evaluation harness with human review and regression testing
  • Production-grade prompt versioning and rollout controls
  • SOC 2 Type II with audit logs and RBAC
  • Multi-model routing across OpenAI, Anthropic, Google, and self-hosted endpoints

Limitations

  • Pricing oriented to mid-market and enterprise — limited free tier
  • Lighter on prebuilt SaaS connectors than agent-first platforms
  • Workflow visual builder is less mature than dedicated agent builders

Based on evaluations in 1 ranking: Best LLM App Platforms for Building AI Agents in 2026

About Vellum

Vellum is an LLM application development platform founded in 2023 in San Francisco. The product targets engineering teams that need versioned prompts, evaluation pipelines, and deployment infrastructure for shipping AI features into production applications.

The platform combines a Prompt IDE for testing variants across providers (OpenAI, Anthropic, Google, Azure), an Evaluation suite for regression testing prompt changes against test cases, a Workflows visual builder for chaining LLM calls with code, retrieval, and conditional logic, and a Deployments layer with versioning, monitoring, and request logs. Vellum supports retrieval-augmented generation through managed vector indexes and integrates with customer-supplied embeddings. Pricing starts with a free Developer tier (limited requests), with paid Pro plans approximately $500/month and Enterprise pricing custom-quoted as of public docs in April 2026.

Integrations (4)

Anthropic native
Azure OpenAI native
Google Vertex AI native
OpenAI native

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