# AuthPlane vs Auth0: Self-Hosted MCP Auth vs the Managed Incumbent - Published: 2026-08-06 - Tag: COMPARISON - URL: https://authplane.ai/blog/authplane-vs-auth0/ - Excerpt: Auth0's Auth for MCP reached GA in May 2026. AuthPlane is the self-hosted, open-source alternative. A fair comparison on hosting, agent identity, and data residency. --- *Part of our field guide to MCP server authentication.* Your MCP server works. The demo went fine, the team is already routing real tool calls through it, and then someone in standup asks the question that always shows up two weeks late: who's actually allowed to call this thing, and can we prove it after the fact? That's usually the moment a team starts shopping for an authorization layer, and for most of them it comes down to two options: the identity platform they already pay for, or a newer tool built specifically for MCP. Here's how AuthPlane and Auth0 actually compare once you get past the landing pages. ## TL;DR Auth0 and AuthPlane both provide an OAuth authorization layer for MCP. The difference is where it runs and how each product models agent identity and delegation. Auth0 is the managed incumbent. Its Auth for MCP product reached general availability in May 2026, it integrates with the Okta identity platform, and it's the lowest-effort choice if you already live in that ecosystem and can use a vendor-managed cloud. AuthPlane is the self-hosted, open-source option. It runs inside your own infrastructure, provides an explicit `agent_id` model and RFC 8693 actor-chain claims, and fits teams that need direct operational control over the authorization server, signing keys, token records, and vaulted credentials. It's also intentionally narrow and still early (v0.1.x), with a managed cloud offering in the works but not yet available. Short version: if you already use Auth0 or Okta and a managed service fits your requirements, Auth0 is the practical call. If you need to operate the authorization layer yourself, or explicit MCP-focused agent identity is a first-class need, AuthPlane is built for that case. ## What is Auth0's MCP offering? Auth0 is one of the most established identity platforms on the market, owned by Okta since 2021. Its Auth for MCP product became generally available on May 6, 2026, after a run in early access that started the previous November. If Auth0 is already part of your identity stack, this is the section worth reading closely. On the MCP side, Auth for MCP covers the parts of the authorization model that matter for production: - OAuth 2.1 security practices and OpenID Connect, with Universal Login handling the user sign-in step. - Client ID Metadata Documents (CIMD) for URL-based client registration, alongside pre-registration and Dynamic Client Registration where those approaches fit. - On-Behalf-Of token exchange under RFC 8693, preserving the original user in `sub` and recording participating services in nested `act` claims. - A Resource Parameter Compatibility Profile for MCP resource identifiers and RFC 8707-style audience binding. - Token Vault for storing and refreshing third-party tokens, with pre-built connections to Google, GitHub, Microsoft, Slack, and 30-plus other providers. - Auth0 Fine-Grained Authorization (FGA), a separate relationship-based authorization service that can treat agents as first-class principals for resource- and tool-level permission decisions. It's designed for standards-compliant MCP clients and common agent environments. Actual compatibility still depends on the client's registration method, redirect behavior, and support for the relevant MCP authorization flow. ## Where do AuthPlane and Auth0 overlap? Both cover the standards floor expected in current MCP authorization deployments: PKCE-protected OAuth flows, resource- or audience-bound access tokens, authorization-server discovery, scoped access, token exchange, and federation to an upstream identity provider. The spec itself has been moving fast. The 2025-11-25 release is what most production MCP deployments were built against, and it's still what AuthPlane's documentation targets today. Then, on July 28, 2026, after months as a release candidate, the working group shipped 2026-07-28: a larger revision that drops the stateful handshake in favor of a stateless protocol core, formally deprecates Dynamic Client Registration in favor of CIMD, and adds RFC 9207 issuer validation. As of this writing, AuthPlane's public docs and RFC compliance table still describe support for 2025-11-25. Auth0's CIMD support already lines up with where the new spec is heading, though its docs haven't yet published a full 2026-07-28 compliance statement either. Expect both vendors to catch up over the coming weeks; the comparison below reflects what's documented today. If your only question is whether you can place a standards-based OAuth layer in front of an MCP server, both answer yes. The decision lives in the differences below, not the overlap. ## How do AuthPlane and Auth0 actually differ? This is where the two-horse race actually splits. Three differences decide most evaluations: hosting model, product scope, and how each one represents agent identity. {% table %} - Dimension - AuthPlane - Auth0 (Okta) --- - Hosting - Independently self-hosted in your infrastructure - Public or private vendor-managed cloud --- - License - AGPL-3.0 server; Apache-2.0 SDKs - Proprietary --- - Built for - MCP authorization and agent delegation - Broad human identity platform with MCP and AI-agent capabilities --- - MCP support - Documents MCP Authorization spec 2025-11-25 end to end - Auth for MCP, GA May 2026; CIMD and resource-parameter compatibility --- - Agent identity - Explicit `agent_id` plus RFC 8693 actor-chain claims - OBO preserves the user and nested `act` chain; Token Vault and optional FGA --- - Token data path - Authorization server, keys, token records, and vault stay under your infrastructure control - Token issuance runs in Auth0 public or private managed cloud --- - Maturity - Early (v0.1.x), narrow focus, not SOC 2 certified (self-hosted means the certification is yours) - Established platform and enterprise footprint --- - Best when - You need self-operated, open-source, MCP-focused auth - You already run Auth0 or Okta and prefer a managed platform {% /table %} **Hosting and data residency.** This is usually the first filter. Auth0 offers multi-tenant Public Cloud and dedicated Private Cloud deployments on AWS and Azure, but both are managed services with weekly automatic updates. AuthPlane is software you deploy and operate inside your own boundary, as a single Go binary today (a managed cloud version is on AuthPlane's roadmap, but it isn't available yet, so self-hosting is currently the only way to run it). For teams with on-prem, air-gapped, or direct operator-control requirements, that difference tends to be decisive. **MCP-focused identity, or broader platform identity.** Auth0 preserves complete service-delegation chains through nested `act` claims in its OBO flow, and its optional FGA layer lets you model agents as first-class principals with relationship-based rules. AuthPlane differentiates with an explicit `agent_id` and `agent_chain` model built directly on top of the same RFC 8693 `act` claim, so a downstream MCP server can gate on the current actor without walking a nested tree by hand. The distinction isn't whether Auth0 supports delegation; it does. The distinction is product model and operational scope: AuthPlane's extension exists purely to make agent-aware authorization decisions cheap inside an MCP tool handler. **Platform breadth, or focused scope.** Auth0 brings years of enterprise hardening, SSO and directory tooling, a broad set of authentication features, and a large support organization. AuthPlane is at v0.1.x and deliberately narrow, and it says so plainly in its own docs: it's validated against Claude Desktop, Claude Code, and MCP Inspector, with Cursor and VS Code support still tracked separately, and it isn't SOC 2 certified because self-hosted software makes that certification yours to earn. If you need a broad identity platform for humans and agents across a large organization, Auth0's maturity is a real advantage. ## When is Auth0 the right call? - You already run Auth0 or Okta, and extending that platform to MCP is the path of least resistance. - Your identity and token issuance requirements can be met by a vendor-managed public or private cloud. - You want one platform covering human SSO, directories, agent auth, and enterprise support. - You value a long production track record and managed operations over independently running the authorization server. ## When is AuthPlane the right call? - You need to deploy and operate the authorization server inside your own environment. - You want signing keys, token records, and vaulted credentials to remain under your infrastructure control. - Explicit agent identity and delegation chains are a first-class need in the token model. - You want source-auditable auth you can run and fork yourself (AGPL-3.0 server, Apache-2.0 SDKs). - You're comfortable running a focused, early-stage tool in exchange for full operational control of the auth layer. AuthPlane is open source, so the honest way to decide is to point it at your own MCP server for an afternoon and compare it with Auth0 on the requirements that actually matter to you. That's the same test the team from the top of this article should run: stand up AuthPlane against a staging server, see if it answers the question that started the whole evaluation, and then decide whether a managed platform is worth the trade-off. If Auth0 fits better, use Auth0. ## Frequently asked questions **Is Auth0 open source?** No. Auth0 is a proprietary platform delivered through managed cloud deployments. AuthPlane is open source, with the server under AGPL-3.0 and the SDKs under Apache-2.0. **Can I self-host Auth0 for MCP?** Not in the sense of installing and independently operating the Auth0 authorization server. Auth0 offers dedicated Private Cloud deployments on AWS and Azure, but its own documentation describes them as managed services, complete with scheduled updates Auth0 controls. **Does Auth0 support agent identity and delegation?** Yes. Auth0 OBO token exchange preserves the original user and records the service chain in nested `act` claims. Token Vault supports third-party credentials across 30-plus providers, and Auth0 FGA can add relationship-based authorization that treats agents as principals. AuthPlane adds an explicit `agent_id` and `agent_chain` model on top of the same RFC 8693 mechanics and packages it in a narrower, MCP-focused server. **When did Auth0 support MCP?** Auth for MCP reached general availability on May 6, 2026. AuthPlane's docs currently document support for the MCP Authorization specification dated 2025-11-25; note that the MCP working group published a newer, larger spec revision, 2026-07-28, after this article's original publication, and both vendors' public documentation are still catching up to it. ## Sources *Primary and vendor sources, accessed August 6, 2026.* - Auth0, [Auth for MCP Is Now Generally Available](https://auth0.com/blog/auth0-auth-for-mcp-servers-generally-available/): GA date, CIMD, OBO token exchange, and MCP resource support. - Auth0 Docs, On-Behalf-Of Token Exchange: `sub` preservation, nested `act` claims, and delegation-chain limits. - Auth0 Docs, Register Applications with CIMD: CIMD requirements and MCP resource-parameter guidance. - Auth0, [Token Vault](https://auth0.com/features/token-vault): supported third-party credential storage and exchange, 30-plus providers. - Auth0 Docs, Private Cloud Deployments (AWS and Azure): private-cloud options are dedicated managed services, weekly automatic updates. - Auth0, [Fine-Grained Authorization](https://auth0.com/fine-grained-authorization): relationship-based authorization for apps, APIs, MCP servers, and agents. - Model Context Protocol, [The 2026-07-28 Specification](https://blog.modelcontextprotocol.io/posts/2026-07-28/): final release date, release-candidate lock date of May 21, 2026, and what changed from 2025-11-25. - AuthPlane Docs, [RFC compliance](https://docs.authplane.ai/reference/rfc-compliance/): current 2025-11-25 MCP Authorization spec coverage and RFC-by-RFC support table. - AuthPlane Docs, [Agent identity](https://docs.authplane.ai/concepts/agent-identity/) and [Delegation & act-chain](https://docs.authplane.ai/concepts/delegation-act-chain/): `agent_id`/`agent_chain` claims and RFC 8693 mechanics. - AuthPlane, [authserver and SDK repositories](https://github.com/authplane): current open-source product capabilities, v0.1.x status, and licensing (AGPL-3.0 server, Apache-2.0 SDKs). *Last updated: August 6, 2026. The MCP auth landscape moves fast. Verify GA dates, feature status, and version numbers against vendor documentation before publishing.*