Instant MCP authorization using Keycloak
If you are exposing tools over MCP, you usually do not want every client on the network calling them anonymously. Even for a local prototype, you typically want a real login flow, consent, scoped access tokens, and a clean way to validate who is allowed to run what.
Keycloak is the easiest way to do that without inventing your own authorization layer. It already handles browser login, consent, token issuance, JWKS discovery, and OAuth metadata. Your MCP server just needs to behave like a protected resource and validate bearer tokens correctly.
In this guide, we will build a tiny calculator MCP server in Python, protect it with Keycloak, and connect to it from VS Code using Dynamic Client Registration (DCR). By the end, VS Code will open a browser to Keycloak, you will sign in, approve access to the mcp:run scope, and then call your MCP tools directly from chat.