---
title: "Why does my API key return a 401 error?"
type: "faq"
url: "https://docs.spur.us/knowledgebase/faqs/why-does-my-api-key-return-a-401-error"
category: "Spur Platform & Data"
product: "context-api"
publishedAt: "2026-09-03T12:00:00.000Z"
updatedAt: "2026-09-03T12:00:59Z"
---

# Why does my API key return a 401 error?

A 401 from the Context API usually means the API key is invalid, expired, or missing from the request. Common causes: the key was rotated or revoked, the key is being sent in the wrong header format, or the subscription has lapsed. Check your API key under Settings → API and confirm your subscription is active before retrying.