[ERROR] Error: COOKIE_SECRET is not defined. A secret key is required for signing cookies. -
Hey !
I am following the guide on setting up Remote MCP with oauth and I run into 2 issues (let me know if this is a wrong thread - couldn't find a better one).
Link: https://developers.cloudflare.com/agents/guides/remote-mcp-server/#connect-your-remote-mcp-server-to-claude-and-other-mcp-clients-via-a-local-proxy
1. (minor) - guide assumes the localhost is available at 8787 but default worker port after cloning the repo is 8788. Maybe my env impacted this not sure
2. (major) - after I created an GitHub OAuth app and added local secrets but I ran into COOKIE_SECRET unset
I couldn't find any docs / help on this - would be much appreciated
Cloudflare Docs
Build a Remote MCP server · Cloudflare Agents docs
This guide will walk you through how to deploy an example MCP server to your Cloudflare account. You will then customize this example to suit your needs.

1 Reply
Fixed it by chaning the nam of the env var to what the client really expects + generating types
env.COOKIE_ENCRYPTION_KEY