# Vellum AI

**Canonical:** https://apis.io/providers/vellum/  
**Website:** https://www.vellum.ai  
**APIs profiled:** 16

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.

## Kin Score — 38.5 / 100 (thin)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 38.5).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 53.3 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 23.7 |
| Developer Ergonomics | 23.8 |
| Commercial Clarity | 46.1 |
| Access Clarity | 46.1 |

## Agent readiness — 35.9 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | verified |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Free · Self-serve signup — onboarding: self-serve, pricing: free, trial: no (confidence: high).

## APIs (16)

- **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 ...
- **Vellum AI Default API** — The Default API from Vellum AI — 8 operation(s) for default.
- **Vellum AI subpackage_deployments API** — The subpackage_deployments API from Vellum AI — 7 operation(s) for subpackage_deployments.
- **Vellum AI subpackage_documentIndexes API** — The subpackage_documentIndexes API from Vellum AI — 3 operation(s) for subpackage_documentindexes.
- **Vellum AI subpackage_documents API** — The subpackage_documents API from Vellum AI — 3 operation(s) for subpackage_documents.
- **Vellum AI subpackage_events API** — The subpackage_events API from Vellum AI — 1 operation(s) for subpackage_events.
- **Vellum AI subpackage_folderEntities API** — The subpackage_folderEntities API from Vellum AI — 2 operation(s) for subpackage_folderentities.
- **Vellum AI subpackage_sandboxes API** — The subpackage_sandboxes API from Vellum AI — 3 operation(s) for subpackage_sandboxes.
- **Vellum AI subpackage_testSuiteRuns API** — The subpackage_testSuiteRuns API from Vellum AI — 3 operation(s) for subpackage_testsuiteruns.
- **Vellum AI subpackage_testSuites API** — The subpackage_testSuites API from Vellum AI — 3 operation(s) for subpackage_testsuites.
- **Vellum AI subpackage_uploadedFiles API** — The subpackage_uploadedFiles API from Vellum AI — 1 operation(s) for subpackage_uploadedfiles.
- **Vellum AI subpackage_workflowDeployments API** — The subpackage_workflowDeployments API from Vellum AI — 10 operation(s) for subpackage_workflowdeployments.
- **Vellum AI subpackage_workflowExecutions API** — The subpackage_workflowExecutions API from Vellum AI — 1 operation(s) for subpackage_workflowexecutions.
- **Vellum AI subpackage_workflows API** — The subpackage_workflows API from Vellum AI — 1 operation(s) for subpackage_workflows.
- **Vellum AI subpackage_workflowSandboxes API** — The subpackage_workflowSandboxes API from Vellum AI — 1 operation(s) for subpackage_workflowsandboxes.
- **Vellum AI subpackage_workspaceSecrets API** — The subpackage_workspaceSecrets API from Vellum AI — 1 operation(s) for subpackage_workspacesecrets.

## Agentic access (1)

- **Vellum Agentic Access** — 59 operations · 32 acting

## Security (2)

- **Vellum Authentication** — apiKey · 1 scheme
- **Vellum Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **Vellum Plans Pricing**

## Tags

LLM Platform, Prompt Engineering, Workflows, Evaluations, LLMOps, RAG, Observability, Datasets, Deployment, Multi-Provider, Agent Builder, Self-Hosted

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/vellum/). Scores are computed from the provider's own public artifacts under a published rubric.