Versine vs. AgentID
AgentID and Versine are both OpenID Connect providers you add next to your existing login. They answer different questions. AgentID asks who the agent is. Versine asks who the agent is working for.
Last reviewed September 25, 2026
Two models of agent identity
The agent as its own user. The agent has its own identity, credentials and permissions. Your platform sees a new user that happens to be software, and the person who runs it is a separate account, or metadata on the agent’s.
The agent as a delegate. The agent acts for a person. The account it creates or signs in to is that person’s, and the person keeps control of what the agent can do.
AgentID is built on the first model. Versine is built on the second. Which one your platform needs depends on whether you expect agents to be your customers, or to bring you your customers.
How AgentID works
An agent’s identity is an AgentMail inbox address. The agent enrolls a browser once using its AgentMail API key, which creates a signing key that stays in that browser. When your app sends it to “Sign in with AgentID”, the enrolled browser signs a one-time challenge and your app receives a standard ID token with a stable subject, the agent’s email address and a marker that the user is an agent.
Apps that register with AgentID can also request the verified email and name of the agent’s human owner, and can limit how many agent accounts one owner creates. Integration is an OIDC connection in Clerk, Auth0, Supabase or similar, and AgentID is free for apps. AgentMail makes money by selling inboxes to agent builders.
Which agents can use it
Only agents that have an AgentMail inbox and an enrolled browser. That is a natural fit for developers building their own agents on AgentMail. It doesn’t cover the general-purpose agents people already use, such as browser assistants and computer-use agents, which have no AgentMail identity unless someone sets one up for them.
AgentID is also building a marketplace in the AgentMail dashboard where agents can discover apps that support it. Until that ships, agents find it through the button on your login page, like any other provider.
Where the person fits
With AgentID, the account on your platform belongs to the agent. If the person who runs it wants to use your product too, AgentID’s suggestion is for the agent to invite them into a team or organization. That works when your platform has teams. It also means the person and the agent hold separate accounts, and whatever the agent set up belongs to the agent’s.
For many consumer and prosumer products, the person is the customer. They expect the account the agent opened for them to be theirs, with their name, their email and their billing.
How Versine differs
Any browser agent can sign up
An agent without Versine clicks “Are you an agent?”, solves a short automatic proof of work and creates a claimable account. It needs no inbox, API key or enrollment. Your platform receives an ordinary OIDC login for a restricted, 24-hour account with signed claims describing its state and permissions.
The account becomes the person’s
The agent gives its user a private claim link. The person signs up for Versine, or signs in, verifies their email and accepts your terms. The account keeps the same user identifier on your side, so everything the agent did is already in the person’s account.
Connected agents sign up as the person
When a person has connected their agent to Versine through MCP, the agent signs up for a full account with the person’s verified identity from the start. The person approves on their phone when your platform needs their consent or details, and can revoke or block any platform later.
Side by side
| Dimension | AgentID | Versine |
|---|---|---|
| Whose account it is | The agent’s, with its own email address | The person’s the agent works for |
| What the agent needs | An AgentMail inbox and an enrolled browser | A browser, or Versine MCP for a full account |
| Signup with no person present | Yes, for enrolled agents | Yes, for any browser agent, with claimable accounts |
| How the person gets access | The agent invites them to a team, if your app has teams | A claim link hands over the same account |
| Owner information | Owner’s verified email and name, if requested | The person’s verified identity once claimed or connected |
| Emailing the agent | Yes, the agent has a real inbox | No. Claimable identifiers don’t receive mail |
| Abuse controls | Per-owner limits on agent accounts | Proof of work that escalates for unclaimed accounts |
| Integration | OIDC connection; free for apps | OIDC connection |
| Built for | Developers building agents on AgentMail | People using the agents they already have |
When AgentID fits better
- Agents are your customers. If you sell to developers whose agents need their own seats, credentials and permissions, the agent-as-user model is the right one.
- You want to email the agent. An AgentID agent has a real inbox for onboarding, receipts and support.
- Your users build on AgentMail. Their agents already have AgentID, so supporting it is a short configuration change.
Both are OpenID Connect providers, so you can offer both. Versine covers people arriving through their agents; AgentID covers agents that are users in their own right.
Frequently asked questions
Is AgentID related to Microsoft Entra Agent ID?
No. Microsoft Entra Agent ID manages identities for agents inside an organization’s Microsoft tenant. AgentID is a sign-in provider from AgentMail. This page compares Versine with the latter.
Can a person use an account their agent created with AgentID?
Not directly. The account belongs to the agent. The person can join through a team invitation if your platform supports teams. With Versine, the person claims the account itself.
Does Versine give agents an email address?
Claimable accounts get a unique identifier in email format that can’t receive mail and is marked unverified. Your platform gets the person’s real, verified email once they claim the account.
How long does integration take?
Both are an OpenID Connect connection in your existing auth provider. Versine also sends signed webhooks when accounts are authorized or claimed. See the integration guide.