Client SDK

Client SDK & API Reference

Welcome to Vellum’s Client SDK and API documentation! Here you’ll find information about the various HTTP endpoints available to you, as well as the requests and responses that they accept and return.

We’ll be exposing more and more of our APIs over time as they stabilize. If there is some action you can perform via the UI that you wish you could perform via API, please let us know and we can expose the relevant API here.

API Stability

Some of the APIs documented within are undergoing active development. Use the Beta and GA tags to differentiate between those that are stable and those that are not. GA stands for generally available.

Base URLs

Some endpoints are hosted separately from the main Vellum API and therefore have a different base url. If this is the case, they will say so in their description.

Cloud-hosted Vellum

For customers using Vellum’s cloud-hosted offering, unless otherwise specified, all endpoints use https://api.vellum.ai as their base URL.

Self-hosted/VPC Vellum

For customers who self-host Vellum in a VPC environment, your base URLs will be different from the cloud-hosted version. If your Vellum application URL is https://app.vellum.company.com, then your API base URL will typically be https://api.vellum.company.com.

When configuring the Vellum client SDKs in a self-hosted environment, you’ll need to specify the correct base URLs. For example, in the Python SDK:

1from vellum import Vellum, VellumEnvironment
2
3# For self-hosted/VPC deployments
4client = Vellum(
5    api_key="your-api-key",
6    environment=VellumEnvironment(
7        default="https://api.vellum.company.com",
8        predict="https://api.vellum.company.com",
9        documents="https://api.vellum.company.com"
10    )
11)

If you’re unsure about the correct base URLs for your self-hosted deployment, please contact your Vellum administrator or reach out to Vellum support.

Official API Clients

Vellum maintains official API clients for Python, Node/Typescript, and Go. We recommend using these clients to interact with all stable endpoints. You can find them here:

Python
Node/Typescript
Go