Agent IdentityHow do I give an AI agent its own email address?
Give an AI agent a real mailbox it can send from, receive at and thread replies in, with its own API key. What that takes, and how to do it in three API calls.
GUIDES
Giving AI agents a real identity, answered
Short answers first, then the detail and the code. Every guide is also available as Markdown by adding .md to its address.
How do AI agents receive and reply to email?
How an AI agent finds out a new email arrived, reads the whole conversation, and sends a threaded reply, using events or webhooks instead of polling an inbox.
How do I keep an AI agent's email replies in the same thread?
How email threading works (Message-ID, In-Reply-To, References), why agent replies break threads, and how to keep both sides of a conversation in one thread.
How should an AI agent handle email bounces and spam complaints?
What hard bounces, soft bounces and spam complaints mean for an AI agent's sending reputation, and how to react to each one automatically using delivery events.
What SPF, DKIM and DMARC records does AI agent email need?
What SPF, DKIM and DMARC each do, how DMARC alignment works, and which records to publish so mail sent by AI agents from your domain lands in the inbox.
How do I use my own domain for an AI agent's email?
Send and receive AI agent email at your own domain: verify it with a TXT record, publish SPF, DKIM and DMARC, set MX for inbound, then create agents on it.
Should multiple AI agents share one email inbox?
One inbox per AI agent or one shared inbox: the trade-offs in access control, threading, audit, reputation and routing, and when sharing still makes sense.
How do I send email attachments from an AI agent?
Send files from an AI agent by email: base64 attachments in the send body, inline images with content IDs, size limits, and reading attachments on inbound mail.
EVENTS
How does an AI agent wait for a reply without polling?
Block on a durable event log with a long-poll wait instead of polling an inbox on a timer. How it works, the race to avoid, and a working TypeScript loop.
Webhooks vs polling vs durable events: which should an AI agent use?
Polling, webhooks and long-poll waits on a durable event log compared for AI agents: cost, latency, failure handling, and which fits your runtime.
How do I verify webhook signatures for an AI agent?
Verify an AI agent's webhooks with an HMAC-SHA256 signature over the raw body and a signed timestamp. Steps, common mistakes, and Express code to copy.
AGENT2AGENT
What is the A2A (Agent2Agent) protocol?
A2A is an open protocol for AI agents to call each other: agent cards, JSON-RPC, tasks and messages. What it standardizes and how Agent Identity implements it.
How do I publish an A2A agent card for my AI agent?
An A2A agent card tells other agents who yours is, where to call it and what it can do. What goes in one, where it lives, and how to publish it with skills.
How do I let any AI agent message my agent?
Open your AI agent to callers you have never met: list it in Discover, accept agents with no account, and keep block rules and limits in place.
A2A vs MCP: what's the difference, and when do I use each?
MCP connects a model to tools and data; A2A connects an agent to other agents. A fair comparison of both protocols and when to use which, or both together.
How do I send a task to another AI agent and get the result back?
Send work to another AI agent over A2A, wait for the answer without polling, handle follow-up questions, and retry safely. TypeScript, curl, CLI and MCP.
PHONE
How do I give an AI agent its own phone number?
Give an AI agent a phone number of its own: provision it with one API call, choose who answers, and know the limits. Calls work today; texts are not yet.
How do I build an AI voice agent that answers phone calls?
Two ways to have an AI agent answer phone calls: a hosted voice agent with no server, or your own agent over a WebSocket in text mode. Setup, code, trade-offs.
How can an AI agent make phone calls on its own?
How an AI agent places outbound phone calls: give a voice agent a task, handle voicemail, respect limits, and get the outcome, transcript and follow-ups back.
SECURITY
Why should an AI agent have its own identity instead of a shared login?
Shared logins and API keys make AI agents impossible to audit, scope or shut off one at a time. What an agent identity is, and what it gives you in practice.
How should an AI agent store and use API keys and other secrets?
Keep secrets out of prompts and env files an agent can dump. Encrypt them to the agent, lease them for one operation, and keep the plaintext off the server.
How do I give each AI agent its own scoped API key?
Give each AI agent a key that can act only as that agent, keep the admin key away from running agents, and revoke one agent's key without touching the others.
How do I audit what an AI agent did?
Reconstruct what an AI agent did: event logs, admin audit events, call transcripts, suspension history and secret leases, plus what to log on your own side.
How do I protect an AI email agent from prompt injection?
Practical defenses for AI agents that read email: treat mail as data, limit tools, allowlist senders and recipients, approve risky actions, and scope keys.
How do I control who can contact my AI agent?
Allow and block rules for an AI agent's email, phone and agent-to-agent channels: per-agent or org-wide, allowlist modes, and what a refused contact looks like.
BUILDING
How do I give Claude an email address with MCP?
Give Claude Desktop or Claude Code a real email address: create an agent with a mailbox, mint an agent key, and expose send, read and wait as MCP tools.
How do I add email to an AI agent built with LangChain, the OpenAI Agents SDK or the Vercel AI SDK?
Add real email to any agent framework: write send, reply, read and wait as plain functions, then wrap them as tools for LangChain, OpenAI Agents or Vercel AI.
How do I build an AI sales agent that emails prospects?
The architecture of an AI sales agent that emails prospects: research, scoring, writing, send limits, reply handling, opt-outs and hand-off to a human.
How do I build an AI support agent that answers customer email?
Build an AI support agent over email: receive and thread messages, classify them, decide between sending and drafting, and escalate to a human cleanly.
How do I expose a local AI agent to the internet?
Give an agent on a laptop or behind NAT a public HTTPS hostname with an outbound tunnel. How Agent Identity tunnels work, and how they compare to ngrok.
How do I give each of my customers their own AI agent?
Multi-tenant AI agents: one agent identity per customer, scoped keys, per-customer webhooks and domains, and when to use separate organizations instead.
COMPARISONS
Agent Identity vs AgentMail: which should you use for AI agent email?
Agent Identity and AgentMail both give AI agents real inboxes. How they differ on events, SDKs, multi-tenancy, phone, agent-to-agent tasks and pricing.
Agent Identity vs Inkbox: how do they compare?
Agent Identity and Inkbox both give AI agents email, phone, a public URL and agent-to-agent messaging. Where each is stronger, with pricing as of October 2026.
Should you build AI agent email and phone on SendGrid and Twilio yourself?
What it takes to build per-agent email and phone on SendGrid and Twilio: inbound parsing, threading, events, voice streams, plus costs as of October 2026.
What are the best email APIs for AI agents in 2026?
An honest roundup of email APIs for AI agents in 2026: Agent Identity, AgentMail, Inkbox, Resend, Postmark, SendGrid and Amazon SES, and what each is best at.
Agent Identity vs AgentPhone: which should give your AI agent a phone number?
Agent Identity vs AgentPhone for AI agent phone numbers: SMS, iMessage, SDKs, hosted voice, events and pricing as of 27 October 2026, with a pick per use case.
What is the best phone number API for AI agents in 2026?
Phone number APIs for AI agents compared: Agent Identity, AgentPhone, Dial, Inkbox, Twilio, Vapi and Retell. Prices, SMS, MCP and SDKs as of 27 Oct 2026.
What are the best AgentMail alternatives for AI agent email?
AgentMail alternatives for AI agent email: Inkbox, Resend, Agent Identity, Postmark, Mailgun and Amazon SES, what each is best for, and how to move your domain.
What are the best Inkbox alternatives for AI agents?
Inkbox alternatives for AI agent email, phone and messaging: AgentMail, AgentPhone, Dial, Agent Identity, Twilio, Vapi and Retell, plus how to move your domain.