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Spring AI is the JVM path to an MCP server, and its mcp-security modules are the only Java option that can be a full OAuth authorization server with dynamic client registration — via the mcp-authorization-server module, built on Spring Authorization Server. The official Java SDK deliberately delegates authorization to Spring, so this page is really about the Spring security modules. They’re authoritative; this page covers the choices and the one gotcha that matters most for MCP Manager.
Start with Building Your Own MCP Server for the requirements and the auth-mode decision tree. This page is the Spring AI layer on top.

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Serve the STREAMABLE protocol

Use the WebMVC server starter (spring-ai-starter-mcp-server-webmvc) and set spring.ai.mcp.server.protocol=STREAMABLE (or STATELESS for a stateless deployment). That gives you the Streamable HTTP transport MCP Manager requires.
mcp-security supports WebMVC, not WebFlux — a WebFlux MCP server isn’t covered by the security modules today. And as with every framework here, don’t ship a server that only speaks the legacy HTTP+SSE transport; MCP Manager won’t connect to it.

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Choose a security module per MCP Manager mode

mcp-security has two distinct modules. Pick the one matching your chosen MCP Manager mode.
You wantUse in SpringNotes
Standard OAuth + DCRmcp-authorization-server (McpAuthorizationServerConfigurer.mcpAuthorizationServer())Built on Spring Authorization Server; DCR is on by default. Also serves RFC 8414 + RFC 9728 metadata
Pre-registration / bearer tokenmcp-server-security (McpServerOAuth2Configurer.mcpServerOAuth2())Resource server: validates inbound JWTs against an issuer, serves RFC 9728 at /.well-known/oauth-protected-resource/mcp
Token in a headerMcpApiKeyConfigurer.mcpServerApiKey()API-key auth, maps to MCP Manager’s header-token mode
See Spring AI — MCP Security and the Securing MCP Servers blog post.

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The gotcha: the default client repository is in-memory

If you run mcp-authorization-server, registered clients are stored in Spring Authorization Server’s RegisteredClientRepository, which defaults to InMemoryRegisteredClientRepository — dev/test only, and ephemeral. On a multi-instance deployment that’s the classic DCR failure: MCP Manager registers against one instance, the authorize hop lands on another, and the client isn’t found. The fix is to wire a JdbcRegisteredClientRepository backed by a shared database (applying the oauth2-registered-client-schema.sql tables). This is an explicit configuration step — it does not happen automatically.
Switching to JdbcRegisteredClientRepository is required for any production or multi-instance deployment. Leaving the default in-memory repository in place is the single most common reason a Spring-based DCR server works in testing and fails once it scales.

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MCP Manager compatibility checklist

1

STREAMABLE protocol on WebMVC

Set spring.ai.mcp.server.protocol=STREAMABLE with the WebMVC starter; mcp-security doesn’t cover WebFlux.
2

Pick the right module

mcp-authorization-server for DCR; mcp-server-security for bearer-token resource-server; McpApiKeyConfigurer for header tokens.
3

Use JdbcRegisteredClientRepository

Replace the default in-memory client repository with the JDBC one so registrations survive restarts and are shared across instances.
4

Public issuer and resource

Ensure the authorization server’s issuer and the resource server’s audience are your public URL, so discovery and token validation line up.

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Spring AI gotchas

The default loses clients on restart and isn’t shared across instances. Wire JdbcRegisteredClientRepository for production. See Debug Self-Hosted OAuth.
mcp-security targets WebMVC. If you’re on WebFlux, the security modules don’t apply — plan for WebMVC or handle auth yourself.
A documented limitation of the current modules is that every client supports all resource identifiers. If you rely on per-resource audience separation, validate that behavior against your version.

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Further reading

Spring AI — MCP Security

The authoritative reference for the resource-server and authorization-server modules.

Securing MCP Servers (blog)

A walkthrough of the Spring AI MCP server security model.

Debug Self-Hosted OAuth

The dynamic-client-registration failure and why in-memory storage causes it.

Building Your Own MCP Server

The cross-framework requirements, decision tree, and troubleshooting catalog.