AI Agent Authentication Platforms Compared (2026)

There is no single best AI agent authentication platform, because the seven products people compare under that name answer four different questions.

• Auth0 for AI Agents, Descope Agentic Identity Hub, and Stytch Connected Apps secure agents acting for your own users inside your own auth stack.
• Arcade runs the tools an agent calls and holds the delegated credentials.
• Microsoft Entra Agent ID governs agents inside an enterprise tenant.
• WorkOS auth.md is a registration protocol that tells an agent how to sign up at your app on behalf of a person.
• AgentID is an OpenID Connect provider that gives the agent its own account and tells your app which human owns it.

Pick by the question you are actually asking: is the agent acting for a user, or is it the user?

Disclosure up front: AgentID is built by AgentMail, where I work. Every claim about every product below comes from the vendor's own pages.

What is AI agent authentication, and what are the main methods?

AI agent authentication is the set of methods an application uses to establish which agent is making a request, whether a human authorized it, and what it may do.

The confusion comes from the word "agent" covering three situations that need different machinery:

• Delegated access. An agent that calls Slack on behalf of an employee needs delegated access.
• Workload identity. An agent that runs inside a company's cloud needs a workload identity so internal services trust it.
• An account. An agent that signs up for a SaaS product on its own needs an account, the way a person does.

The platforms in this comparison each grew out of one of those situations:

• Auth0, Descope, and Stytch came from customer identity, so they model the agent as something a user authorizes.
• Arcade came from tool calling, so it models the agent as something that needs credentials for other people's APIs.
• Microsoft Entra came from workforce identity, so it models the agent as a directory object with sponsors.
• AgentID came from email infrastructure for agents, so it models the agent as an entity with its own address that can introduce itself anywhere.

So the methods on the market sort into four groups, the three situations above plus a registration on-ramp for the first:

• Delegated OAuth. Your app or a credential vault issues scoped tokens to an agent acting for a user (Auth0 for AI Agents, Arcade, Descope Agentic Identity Hub, Stytch Connected Apps).
• Registration protocols. A protocol tells an agent how to obtain such a token (WorkOS auth.md).
• Workload and directory identity. Agents inside a perimeter get an identity from the directory or runtime (Microsoft Entra Agent ID, Google Cloud Agent Identity).
• Agent identity providers. A provider issues the agent an OpenID Connect identity of its own (AgentID).

The fork that matters most runs between the first group and the last. The vocabulary for it is principal versus delegate.

• A principal is the account holder the app registers, bills, and emails.
• A delegate acts with borrowed, scoped authority on a principal's behalf.

Hold onto that distinction; it explains most of the table below.

How do the AI agent authentication platforms compare side by side?

The seven platforms split on whether the agent is a principal or a delegate, and on who learns the accountable human. The table summarizes the vendor pages as of September 14, 2026.

Prices are the published starting points and change; check each vendor's pricing page for current numbers.

What does Auth0 for AI Agents do?

Auth0 for AI Agents is Okta's product line for securing agents you build for your own users.

The pitch on the product page is to "let your AI agents identify users, call APIs, and connect to MCP servers more securely." The core pieces are:

• User authentication.
• Token Vault for third-party API credentials.
• Asynchronous authorization through CIBA for human-in-the-loop approvals.
• Fine-grained authorization for RAG pipelines.

Auth for MCP reached general availability on May 6, 2026.

Identity model. Auth0 for AI Agents models the agent as a delegate. Auth0 describes Token Vault this way: "Your agent never actually holds the root key; instead, it asks Token Vault for a temporary, short-lived access token only when it needs to perform a specific task."

A newer feature, Agent as Principal, gives agents "a stable identifier, its own lifecycle management, and its own audit trail" inside your tenant. It was in early access as of a July 30, 2026 post. The marketing page still labels it "Coming Soon," so treat availability as tenant-dependent.

Pricing.

• Free up to 25,000 monthly active users, with two Token Vault connections.
• Essentials from $35 per month at the default slider.
• Professional from $240 per month at the default slider.

Auth0 states it charges for "active agent identities" but publishes no per-agent rate.

Choose it when your agents act for users who already live in your Auth0 tenant and you need vaulted credentials, MCP server auth, or approval flows.

Limits. Auth0 for AI Agents does not give an agent an identity that a different company's login page can accept. The Auth0 platform itself can accept AgentID as an OIDC connection for that case, a useful reminder that the IAM platform and the agent product are different SKUs.

What does Microsoft Entra Agent ID do?

Microsoft Entra Agent ID is "an identity and security framework that extends Microsoft Entra capabilities to AI agents."

The model has three objects:

• Agent identity blueprint: holds credentials and policy.
• Blueprint principal: records the blueprint in a tenant.
• Agent identity: the identity itself.

Microsoft is specific that "unlike user accounts, agent identities don't have credentials of their own. They authenticate using tokens issued by their agent identity blueprint."

An agent can also get an "agent's user account" that pairs 1:1 with the identity and reaches mailboxes, calendars, and Teams.

Accountability. Entra builds accountability in. Every agent has a Sponsor: "Sponsors provide business accountability for agents, making lifecycle decisions without technical administrative access," alongside Owners who handle configuration.

Non-Microsoft agents are supported through an Auth SDK sidecar or workload identity federation, with documented paths for AWS Bedrock and n8n.

Status. Microsoft's Entra what's-new page lists:

• The platform as generally available under April 2026.
• Lifecycle workflows for sponsors GA in May.
• Conditional Access for agent user accounts in public preview in June.

Pricing.

• Base product: "Agent ID is available for all Microsoft Entra customers."
• Security features: "extending Microsoft Entra security features to agents requires Microsoft Agent 365," which is included with Microsoft 365 E7 and sold as an add-on to E5.
• Dollar figures: none are on the page.

Choose it when your organization runs Entra and the agents you care about are internal.

Limits. The boundary is the tenant. Sponsor and Owner are visible to the company running the agent, and a third-party SaaS receiving a sign-in from an Entra agent does not learn who sponsors it.

For the concept behind the name, see what an agent ID is.

What does WorkOS auth.md do?

WorkOS auth.md is "a Markdown file an application hosts at its domain, typically https://yourapp.com/auth.md, that tells agents how to register on behalf of a user."

WorkOS released it on May 21, 2026, and stresses that it "isn't tied to WorkOS infrastructure." Any app can publish one without a WorkOS account. The spec is MIT-licensed on GitHub.

Identity model. auth.md treats the agent as a delegate and defines two flows:

• Agent verified. The agent's identity provider (OpenAI, Anthropic, Cursor, and similar) mints an ID-JAG, an identity assertion JWT vouching that the agent acts for a specific user. The agent POSTs it to the app with no human in the loop.
• User claimed. The agent shows the user a code, and the user signs in and confirms it.

Either way the credential issued is "a scoped access token tied to the user, short-lived and revocable."

The ID-JAG grant is an IETF OAuth working group draft, draft-ietf-oauth-identity-assertion-authz-grant-04, co-authored by Okta's Aaron Parecki.

Adopters. The adopter list on the WorkOS page includes Cloudflare, Firecrawl, Resend, Neon, Parallel, monday.com, and Cloudinary.

Pricing.

• The protocol costs nothing.
• WorkOS AuthKit, if you want the hosted implementation, is free to one million users.

Choose it when your product's account model is human accounts and you want agents to obtain scoped access to those accounts without borrowing passwords.

Limits. The documented limitation is that agent verified only works when the agent's provider participates. Agents built on bare LLM APIs fall back to the user claimed flow.

auth.md and AgentID answer adjacent questions and are compared directly in AgentID vs WorkOS auth.md.

What does Arcade do?

Arcade calls itself "the actions runtime for enterprise AI agents." It sits between agents and the systems they call.

• Arcade handles OAuth against 40 or more providers such as Google, Slack, GitHub, and Salesforce.
• It executes tool calls through MCP servers.
• It keeps the tokens inside its runtime.

Identity model. The homepage states the model plainly: "Authentication runs against your IdP. Authorization is delegated, so the agent acts as its user."

Pricing. Arcade's pricing is usage-based:

• Free: 2,000 auth events and 2,000 tool calls per month.
• Team: $25 per month plus $0.10 per auth event and $0.01 per tool call.
• Enterprise: annual bundles.

Customer logos include LangChain, Snyk, and Relevance AI.

Choose it when the problem is "my agent needs to read this user's Gmail and post to this user's Slack, safely."

Limits. Arcade is not an identity provider. It does not issue an identity the agent can present to an app that has never seen it.

If the problem is "an agent just arrived at my signup page," Arcade is the wrong layer. The two are compared directly in AgentID vs Arcade.

What does Descope Agentic Identity Hub do?

Descope describes the Agentic Identity Hub as its "control plane for AI agent identity. It covers every agent that calls your APIs, every tool your agents use, and every credential those tools need."

The Agentic Identity Hub launched in April 2025 with three pieces:

• Inbound Apps: turn your app into an OAuth authorization server for agents and MCP clients.
• Outbound Apps: a credential vault for the tools your agents call.
• MCP auth SDKs.

Version 2.0, announced January 26, 2026, added agents "as first-class identities alongside human users" and an agent directory.

Protocols. The protocol list is long:

• OAuth 2.1 with PKCE.
• Dynamic client registration and CIMD.
• RFC 8693 token exchange.
• ID-JAG and Cross-App Access.
• Cloud workload OIDC tokens from AWS and GCP.
• SCIM.

Pricing. Descope meters the agent features separately:

• Monthly active consent: counted when a unique user consents to a scope for a resource.
• Monthly active token: any instance where a token is fetched and used to act.

The published tiers:

• Free Forever: 7,500 MAU, 2,000 consents, and 2,000 tokens.
• Pro: from $249 per month billed annually.
• Growth: $799.

Choose it when you are building MCP servers or agents inside a deployment you administer and want per-agent identities, tool-level scopes, and audit in one place.

Limits. The identities Descope issues are scoped to your Descope project. An agent does not carry a Descope identity to another company's login page.

What does Stytch Connected Apps do?

Stytch Connected Apps lets you "turn your app into an identity provider" so that agents and other apps can act on your users' behalf.

Connected Apps ships "Remote Model Context Protocol (MCP) Authorization to make your app agent-ready in minutes."

Protocols. Stytch Connected Apps implements:

• OAuth 2.0 and OIDC.
• OAuth 2.1 with dynamic client registration and CIMD.
• RBAC scopes.
• Device authorization flows for human approval of sensitive actions.

Identity model. A design rule Stytch states directly: "Users can only give an app the same permissions that they themselves already have."

Pricing. Stytch counts users and agents together:

• "Always free: 10,000 monthly active users and AI agents."
• $125 per SSO or SCIM connection beyond the first five.
• Per-MAU pricing above the free tier.

Stytch is listed among Okta's Cross App Access partners. Its own pricing and product pages did not say whether ID-JAG support had shipped when I read them.

Choose it when you already run Stytch for customer auth and want your users' agents to reach your API with scoped, revocable tokens.

Limits. Like Auth0 and Descope, Stytch makes your app an authorization server for delegates. It does not give an agent a portable account of its own.

What does AgentID do?

AgentID, from AgentMail, is an OpenID Connect provider that lets an AI agent sign in to apps with its own verified email identity. It sits behind a "Sign in with AgentID" button that behaves like Sign in with Google.

Identity model. The agent is the principal.

• Every sign-in returns an ES256-signed id_token with a stable sub and the agent's inbox address, verified live when the token is minted.
• Apps that register a client (one RFC 7591 call authenticated with an AgentMail API key) can request the owner_email scope and read the owning human's email from /userinfo.
• The owner claims are deliberately kept out of the id_token so they never land in logs.
• If the agent's credential does not permit disclosure, a request for them fails with a 403 rather than returning a token silently missing the claim.

Integration. Integration is a configuration change rather than code. Add AgentID as a custom OIDC provider in Clerk, Supabase, Auth0, Better Auth, or Auth.js with two values:

• Issuer: https://auth.agentid.com
• Client ID: your client_id

On the agent side:

1. The agent enrolls a browser once by posting an AgentMail API key.
2. The browser generates a non-extractable P-256 key.
3. From then on, the agent signs in from that browser without a human.

An agent with no browser hands the sign-in to its owner in the AgentMail console.

Pricing.

• Free for apps.
• The business model is that agents need an AgentMail inbox to have an AgentID.

Adopters. Listed adopters include Turso, Supermemory, Locus Pro, and Channel3. The public launch is October 6, 2026.

Choose it when agents show up at your login page from outside your organization and you need to know they are agents, recognize the same one next time, and reach the human behind them.

Limits. AgentID does not do delegation, credential vaulting, or MCP tool authorization, and it composes with the platforms above that do.

The Sign in with AgentID button guide is the shortest route to trying it.

Who offers the best AI agent authentication for your situation?

The best AI agent authentication platform depends on where the agent comes from and where it is going.

If your users bring agents to your product and the agent should act as that user, you need an authorization server for delegates. Auth0 for AI Agents, Descope, and Stytch are the mainstream choices, and the decision usually follows whichever of them already runs your login.

auth.md adds a discoverable registration path for agents that do not know your API yet. It is cheap to publish alongside any of the three.

If your agents need to reach other companies' tools on your users' behalf, you need a delegation runtime. Arcade is the purpose-built option; Descope's Outbound Apps and Auth0's Token Vault cover the same ground from inside an identity platform.

If your agents live inside your company and never leave, you need workload and directory identity. Entra Agent ID is the answer for organizations that already run Entra, including for agents hosted on AWS Bedrock or n8n.

Google Cloud Agent Identity does the equivalent with SPIFFE identities on Google's runtime, and reached general availability in August 2026.

If agents arrive at your app as prospective customers, from organizations you have no relationship with, you need an agent identity provider. AgentID is the only product on this list built for that case.

AgentID hands the receiving app the owner's email. auth.md hands it a user the agent acts for, and the others keep the human inside your own tenant.

Most production stacks end up with two of these: your identity platform for your users, plus either Arcade for outbound delegation or AgentID for inbound agent customers. The mistake is buying one and expecting it to do the other's job.

What security considerations apply to AI agent authentication?

Four security questions apply to AI agent authentication regardless of vendor: replay, per-agent revocation, audit, and the accountable human.

1. Can the credential be replayed? Token Vault and Arcade keep long-lived secrets out of the agent's hands. AgentID leaves the agent a key it cannot export and mints a short-lived token per sign-in.
2. Can you revoke one agent without touching a human's account? Delegate models revoke the grant; principal models revoke the agent's own credential.
3. Is there an audit trail that names the agent rather than the user it impersonated? Arcade and Descope log per action; AgentID's jti names each sign-in; Entra logs against the blueprint principal.
4. Does a human stand behind the agent, and who gets to see that? This is the one that separates the products most, and the table's fourth column is the place to check it.

Two data points for scale:

• Agents specifically: HUMAN Security measured agent traffic growing 7,851% year over year in its March 2026 benchmark, from a small 2024 base.
• All bots: Cloudflare put automated requests at 57.5% of web requests to HTML content in June 2026, counting all bot types, not agents alone.

Whichever of these platforms you pick, the traffic it has to sort is no longer a rounding error.