---
seo:
  description: >-
    Public REST API for interacting with UDX as a member. Every request resolves
    to a specific, dated API version via the UDX-Version header; omit it and you
    get…
sidebar:
  label: Overview
title: REST API
---
Public REST API for interacting with UDX as a member. Every request resolves to a specific, dated API version via the UDX-Version header; omit it and you get the oldest version this API has ever shipped, so an integration that never sets it keeps working exactly as it always has.

<ApiOverview source="api-reference" />

## Users

Interactive user session bootstrap.

<ApiTagOperations source="api-reference" tag="users" />

## API Keys

Programmatic credential management.

<ApiTagOperations source="api-reference" tag="api-keys" />

## Rate Limits

The authenticated member's REST request capacity.

<ApiTagOperations source="api-reference" tag="rate-limits" />

## Markets

Market catalog, order books, candlesticks, and trades.

<ApiTagOperations source="api-reference" tag="markets" />

## Combos

Multi-leg markets.

<ApiTagOperations source="api-reference" tag="combos" />

## Orders

Place, amend, cancel, and query orders.

<ApiTagOperations source="api-reference" tag="orders" />

## RFQs

Request quotes from market makers.

<ApiTagOperations source="api-reference" tag="rfqs" />

## Quotes

Respond to RFQs and manage quotes.

<ApiTagOperations source="api-reference" tag="quotes" />

## Portfolio

Account balances, positions, fills, settlements, accounts, and transfers.

<ApiTagOperations source="api-reference" tag="portfolio" />