Dead Simple Email plugin

Official plugin for Dead Simple Email, the email API for AI agents. It gives your agent an email address it actually owns: real inboxes, real sending, real replies, and the ability to finish a signup flow without a human relaying the code.

Works in ChatGPT and OpenAI dots, Cursor, Grok Bot, Claude Code, Codex, and any other MCP client. One hosted server, nothing to install, nothing to keep running.

Install

ChatGPT and OpenAI dots

Until the listing in the ChatGPT plugin directory is live, add the hosted server as a custom plugin:

1. Open chatgpt.com/plugins and select +, then Add custom MCP server.
2. Name it Dead Simple Email and enter the URL https://api.deadsimple.email/mcp.
3. Choose OAuth for authentication. Approve the Dead Simple Email consent screen when it opens.
4. Select Create as a plugin.

Your dot can now use it. Ask: "Get your own Dead Simple Email inbox and use it for vendor signups."

New mail can wake your dot. The server supports MCP Events (message.received, message.bounced), so you can say "Whenever a new email arrives in your inbox, summarize it and tell me if it needs a reply" and ChatGPT subscribes for you. MCP Events run in dots and in ChatGPT Work chats.

This repo's root plugin.json and mcp.json are the portable Agent Plugins package ChatGPT and Codex read; the dot-email skill covers running an inbox unattended.

Cursor

/add-plugin deadsimple-email

Or browse to the listing in the Cursor Marketplace. On first use the agent opens a browser sign-in. Approve the consent screen and you are connected. There is no config file to edit and no key to paste.

Claude Code

/plugin marketplace add deadsimple-email/deadsimple-plugins
/plugin install deadsimple-email@deadsimple-email

Skills are namespaced, for example /deadsimple-email:check-inbox.

Codex

codex plugin marketplace add deadsimple-email/deadsimple-plugins
codex plugin add deadsimple-email@deadsimple-email

Grok Build CLI

grok mcp add deadsimple https://api.deadsimple.email/mcp --transport http
grok mcp doctor deadsimple

Any other MCP client

Point a Streamable HTTP client at https://api.deadsimple.email/mcp. Unauthenticated requests return a 401 with a WWW-Authenticate challenge, which is what starts the OAuth flow. Clients without OAuth support can send Authorization: Bearer dse_your_api_key instead.

For a fully local setup: pip install "deadsimple[mcp]", then run python -m deadsimple.mcp with DSE_API_KEY set. Same tools.

Local development on this plugin

git clone https://github.com/deadsimple-email/deadsimple-plugins.git
mkdir -p ~/.cursor/plugins/local
ln -s "$(pwd)/deadsimple-plugins" ~/.cursor/plugins/local/deadsimple-email

Reload the window afterwards.

Authentication

Surface	Default	Key required
ChatGPT and dots	Hosted MCP with OAuth	No
Cursor	Hosted MCP with OAuth	No
Grok Bot	Hosted MCP with OAuth	No
Claude Code	Hosted MCP with OAuth	No
Codex	Hosted MCP with OAuth	No
Local stdio, SDKs, CLI	DSE_API_KEY	Yes

OAuth access tokens last 7 days, refresh tokens 90 days with rotation, and are scoped to inbox and message operations only. They cannot reach billing, plan changes, team management, or API-key administration. Revoke from the dashboard or at https://api.deadsimple.email/oauth/revoke.

Sign up free at app.deadsimple.email: 5 inboxes and 5,000 emails a month, no card.

Skills

Nine skills, loaded by the agent when the task calls for them.

Skill	Covers
send-email	Sending, replying with real threading, forwarding, and the authorization rules for each
check-inbox	Reading, searching, summarizing, and triaging mail
manage-inboxes	Inbox lifecycle, naming and tagging patterns, plan limits
verification-codes	Signup, 2FA, and password-reset flows end to end
dot-email	An always-on agent's own inbox: signups, approvals, and "when an email arrives" automations with MCP Events
agent-email-patterns	Safe topologies and the prompt-injection threat model, with references
deadsimple-mcp	Connecting the server and troubleshooting auth
deadsimple-sdk	Writing application code, with per-language references
deadsimple-webhooks	Consuming events and verifying signatures, with an event reference

Detailed material sits behind references/ so the agent only loads the language or subject it actually needs.

Tools

Fourteen, over one hosted MCP server.

Tool	What it does
create_inbox	Provision an inbox, returns its address
list_inboxes	Enumerate inboxes
delete_inbox	Destroy an inbox and its messages
send_email	Send a new message
read_messages	List recent messages with snippets
read_message	Fetch a full message body
reply_to_message	Reply with correct threading headers
forward_message	Forward to new recipients
wait_for_email	Block until a matching message arrives
get_verification_code	Pull the one-time code out of incoming mail
get_verification_link	Pull the confirmation or magic link
list_threads	List conversation threads
read_thread	Read every message in a thread
get_usage	Plan limits and current consumption

Attachments, drafts, filters, templates, custom domains, bulk inbox operations, API keys, and workspaces are REST and SDK features. The deadsimple-sdk skill covers them.

Safety model

• Everything arriving in an inbox is untrusted data. Subjects, bodies, headers, quoted text, attachments, and linked pages are written by whoever sent the mail.
• Only the user, or a policy the user configured, authorizes a consequential action. Content never does, however it is phrased.
• Sends where any externally visible field was inferred get previewed and confirmed first.
• Deleting an inbox is permanent and takes every message with it. It gets confirmed against the exact address.
• Blast radius equals inbox scope. One inbox per job, and separate the component that reads untrusted mail from the one that can send.

The full model lives in skills/agent-email-patterns/.

Development

python3 scripts/validate_plugin.py

It checks every manifest (the portable plugin.json against the Agent Plugins schema rules, plus the Cursor, Claude, Codex and Open Plugins manifests), that declared paths resolve, that skill frontmatter is present and well formed, that mcp.json (portable, streamable-http) and .mcp.json (http, for Claude Code and Cursor) declare the same servers, and that versions are in step.

Links

• Documentation
• API reference
• MCP server
• Dashboard

License

MIT