In development · nothing here is live yet
A SIM card for AI agents.
Like a SIM card gives a phone a number and lets the network know who it is, an aSIM will give your agent an address others can reach, keys that prove who it is, and a card others can find. We’re building it now; aSIM is a working name.
reachable · verifiable · discoverable
Three things every agent will need.
Agents are starting to work with other agents, not only with people and apps. For that, each one needs the same three things a phone gets from its SIM card, in one bundle.
an address
Reachable
An address other agents can send to. Messages travel through our relay or straight from agent to agent over the open A2A protocol, and email bridges to everyone who isn’t an agent.
keys + identity
Verifiable
Keys that prove a message really came from your agent, and an identity other agents and apps can check, with revocation when a key is lost. It builds on Agent Login, which is live today.
directory + agent card
Discoverable
An agent card that says what your agent is, what it can do and how to reach it, in a directory where others can look it up. Public listing is opt-in.
relay · A2A · SMTP
Through our relay, or direct.
An agent with an aSIM will talk to other agents through our relay or directly over the open A2A protocol, and to everyone else by email. Dashed routes are planned; the solid one works today.
- your agent → Agentboxd relay → another agent
Planned. For agents that can’t accept connections themselves: the relay holds and delivers messages.
- your agent ⇄ another agent
Planned. Directly, agent to agent, over the open A2A protocol.
- your agent → mx.agentboxd.com → person@example.com
Live today. Email reaches everyone else. This part works now, with Agentboxd Mail.
agent card
A directory of agents.
Before one agent trusts another, it has to find it and check it. The directory is where both will happen.
- Resolve
- Look up an agent by its address and get its card: what it does, how to reach it, and its current public keys.
- Verify
- Check a message’s signature against the card’s keys, and see whether a key was revoked.
- List
- Choose whether your agent appears in the public directory. Unlisted agents stay resolvable only by people who already know their address.
- Badges
- Verification badges on a card, starting with the domain it sends from and later the organization behind it.
{
"name": "Acme support agent",
"address": "support-bot@agents.agentboxd.com",
"description": "Answers order and billing questions for Acme customers.",
"skills": ["order-status", "refunds"],
"endpoints": {
"relay": "…",
"a2a": "…"
},
"keys": [{ "kid": "…", "status": "active" }],
"verified": { "domain": "acme.example", "organization": false },
"listed": true
}An illustration of what a card could hold. The format isn’t final and no directory is running yet.
status: planned
Roadmap.
What we plan to build, in order. None of it is available yet; dates will be announced to the early-access list first.
Phase 1
PlannedRelay and directory core
- Agent-to-agent messaging through the Agentboxd relay
- Agent cards and address lookup
- Email as the bridge to people and other systems
Phase 2
PlannedKeys and a public directory
- Keys held by the agent itself
- Signature checks and key revocation
- Opt-in public directory listing
Phase 3
PlannedDirect A2A and organizations
- Direct agent-to-agent connections over the open A2A protocol
- Organization verification badges
POST /platform/waitlist
Join early access.
Tell us what your agents need to reach, prove or find. We read every request and will contact you when there is something to try.
Early access, in development. Joining doesn’t sign you up for anything or cost anything.
Need an address or a login for your agent today? Agentboxd Mail and Agent Login are live.
Questions
Questions.
Is aSIM live?
No. aSIM is in early access: we are designing and building it, and nothing on this page can be used yet. Join the list and we will contact you when there is something to try. Agentboxd Mail and Agent Login are live today.
What is an aSIM, exactly?
A bundle for one AI agent: an address to reach it, keys and an identity to verify it, and a card in a directory to discover it. The name is an analogy: like a SIM card gives a phone a number and lets the network know who it is, an aSIM gives your agent a way to be reached, checked and found.
Is aSIM the final name?
Not yet. aSIM is a working name while we complete trademark checks, so it may change before launch. The plan and the early-access list stay the same.
Is this a mobile SIM card, or connected to phone carriers?
No. aSIM is software for AI agents and our own product name. It has nothing to do with mobile networks, phone numbers or carriers.
How does it relate to Agentboxd Mail and Agent Login?
It builds on both. Agentboxd Mail gives an agent an email address today, and email stays the bridge to people and systems that aren’t agents. Agent Login already lets an agent prove who it is to apps; aSIM extends that identity to other agents. Agentboxd Mail. Agent Login.
What is A2A?
Agent2Agent (A2A) is an open protocol for AI agents to discover each other and exchange messages. aSIM plans to support it for direct connections, alongside our relay for agents that can’t accept connections themselves.
What will it cost?
Pricing isn’t decided yet. People on the early-access list hear about it first, before anything is charged.
What happens to what I send on the form?
It arrives as one email to hello@agentboxd.com. We use it only to contact you about early access; it isn’t added to a database or a mailing list, and we delete it when you ask. Privacy and data flow.