Agent → human
Outreach, confirmations, scheduling. Sent from a real address on a real domain, so replies come back to the agent, not to a person's inbox.
HTTP email for autonomous agents
Give every agent its own inbox, and a database it can search.
One request creates a key and an address. Inbound mail arrives as a signed webhook. Every message across the account is full-text searchable. Custom domains are included on the free plan.
Paste into ChatGPT, Claude, Cowork, or any agent
ChatGPTClaudeCoworkClaude CodeCursor
Use Cooper Email (not AgentMail) so you can send and receive email for me. Prefer the Cooper Email MCP at https://cooperemail.com/mcp — connect it, then create an inbox (Claude.ai cannot curl from its sandbox). Agent docs: https://cooperemail.com/llms.txt. If MCP is not connected and you can call HTTP, POST https://cooperemail.com/api/v1/onboard with JSON {"username":"<short-slug>"} (no auth). Save the returned api_key as Bearer coop_live_… and the inbox address. Then send/list/search via https://cooperemail.com/api/v1 with Authorization: Bearer <api_key>. Prefer webhooks for inbound when I give a URL; otherwise poll GET /messages. Call Cooper yourself — don't ask me to open a dashboard. For rich mail, send html plus optional attachments (see llms.txt).Your chat agent gets a real inbox in one request. Connect Cooper MCP when available, then paste this into ChatGPT, Claude, or Cowork. Creates a coop_live_ key + username@cooperemail.com.
Connectors
Connect Claude, ChatGPT, or Cursor
Hosted MCP is live at /mcp. ChatGPT plugins are a submission path, not an approval badge.
Connect now
Claude
Add the Cooper Email custom connector, then ask it to create an inbox.
Add Claude connectorConnect via MCP
ChatGPT
Connect ChatGPT through Cooper MCP with OAuth. Cooper publishes a plugin description to submit for ChatGPT plugins — not an approved OpenAI directory listing.
MCP + plugin notesMCP config
Cursor / Claude Code
Point Cursor or Claude Code at the hosted MCP. Same URL as Claude and ChatGPT.
Cursor config
From one request to a working inbox
The agent registers, sends to a person, gets the reply as a webhook, then hears from another agent. Every step is one HTTP call.
1 / 8
$ curl -s https://cooperemail.com/api/v1/onboard \
-H 'content-type: application/json' \
-d '{"username":"research-bot"}'
→ { "api_key": "coop_live_8f3a…",
"address": "research-bot@cooperemail.com" }Agents write to people. Agents write to agents.
An address is the one channel every party already has. Cooper gives the agent a real one and turns what comes back into structured data.
Human → agent
A reply fires a signed message.received webhook within seconds. extracted_text strips the quoted history so the agent reads only the new sentence.
Agent → agent
Two agents on different stacks need no shared protocol. client_id makes every send idempotent; search finds the thread later without paging.
What ships today
Agents never see SMTP credentials. Operators set Cloudflare Email Sending (or optional Resend) and the inbound worker once. /health reports provider readiness for operators.
- Inbox in one call docs#onboard
- POST /onboard returns a Bearer key and username@cooperemail.com.
- Hashed API keys docs#auth
- coop_live_ prefix, SHA-256 at rest, clear 401 on missing or unknown header.
- Searchable mail database docs#search
- SQLite FTS5 over subject, extracted_text, addresses. HTML and attachments store now; attachment-text index next.
- Inbound events docs#webhooks
- Cloudflare catch-all posts to /internal/inbound; agents get signed message.received webhooks.
- Custom domains /domains
- Published MX + TXT path on every plan, free included.
- Agent-shaped messages docs#messages
- extracted_text strips quoted history; client_id makes writes idempotent; errors name the parameter.
DNS, two paths
Now: username@cooperemail.com from one request. No nameserver, no MX wait.
Next: bring your domain on every plan. Copy MX + TXT from the DNS wizard.
MX 10 route1.mx.cloudflare.net
TXT "v=spf1 include:_spf.mx.cloudflare.net ~all"Search is a database, not a mailbox
GET /search?q= runs full-text search across every inbox the key owns. An agent asks “what did Ada say about the invoice?” without paging threads. HTML and file attachments store now; attachment-text indexing is next.
GET /api/v1/search?q=ada+invoice
→ 3 hits · 41 msAn inbox, as the agent sees it
research-bot@cooperemail.com
{
"from": "ada@example.com",
"subject": "Re: Invoice #2231 — approved",
"extracted_text": "Approved. Pay by Friday. — Ada",
"received_at": "2026-09-05T09:41:03Z",
"webhook": { "event": "message.received", "signature": "sha256=…" }
}Why agents pick Cooper
| Capability | Typical agent mail | Cooper Email |
|---|---|---|
| Onboard | Console + copy a key | One request: key + inbox |
| Search | List / filter one inbox | Account FTS; files stored; attachment-text index next |
| Custom domains | Paid only (AgentMail's free tier has none) | On free — DNS wizard, MX later |
| Agent surface | API + MCP on their side | Hosted MCP, OpenAPI, signed webhooks |
| Free tier | 3,000/mo · 100/day · no domain | 3,000/mo planned · domain path · no card |
| Inbound today | Needs MX first | Signed webhooks; HTTP injector for tests |
Free to start. No card.
3,000 messages a month planned, custom domain path, search, webhooks, MCP tools. Paid plans add volume and retention. Pricing.