Provides AI agents with dedicated email inboxes to create addresses, receive verification codes, and manage email conversations.
Also known as send0-dev/send0-v2, @send0/mcp
- Stars
- 0
- Tools
- 7
- Downloads, 30 days
- —
- Latest version
- 0.2.1
- Last commit
- Nov 1, 2026
- License
- AGPL-3.0
What is send0 MCP?
send0 provides AI agents with dedicated email inboxes to create addresses, receive verification codes, and manage email conversations. It exposes 7 tools, such as create_inbox, list_inboxes, wait_for_email.
Summary generated from the project's README
About send0 MCP server
Giving AI agents their own dedicated email inboxes allows them to sign up for services, handle verification codes, and participate in real email conversations. Developers can integrate this server into Claude Desktop, Cursor, or Claude Code by providing a SEND0_API_KEY. The setup supports both cloud-based and self-hosted environments through the SEND0_BASE_URL configuration.
Agents use specific tools to manage their communication, such as create_inbox for generating new addresses like signup-agent@send0.email and wait_for_email to pause until a verification code or link arrives. For managing existing mail, the server provides search_messages for full-text queries, get_message for reading content, and list_threads to view entire conversations. To interact with others, the agent can use send_email to start new threads or reply to existing ones. The system includes safety features by wrapping email bodies in untrusted tags and labeling tools with readOnlyHint or openWorldHint to help clients manage permissions.
What you can do with it
- 1Automating service registrationsAn AI agent can generate a unique email address to sign up for a new web service.
- 2Handling two-factor authenticationThe agent can wait for a specific email to arrive and automatically extract a one-time verification code.
- 3Managing email threadsA developer can instruct an agent to read through an entire conversation from oldest to newest.
- 4Searching for specific communicationsAn agent can find messages from a specific domain using full-text search filters.
Written from the project's README. Every use case is checked against a quote from it.
How to install send0 MCP
Formats verified 10 Nov 2026Add to CursorAdd to GooseInstall send0 MCP in Claude Code
$ claude mcp add --env 'SEND0_API_KEY=<YOUR_SEND0_API_KEY>' send0 -- npx -y @send0/mcpInstall send0 MCP in Cursor
~/.cursor/mcp.json
{
"mcpServers": {
"send0": {
"command": "npx",
"args": [
"-y",
"@send0/mcp"
],
"env": {
"SEND0_API_KEY": "<YOUR_SEND0_API_KEY>"
}
}
}
}Install send0 MCP in VS Code
.vscode/mcp.json
{
"servers": {
"send0": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@send0/mcp"
],
"env": {
"SEND0_API_KEY": "<YOUR_SEND0_API_KEY>"
}
}
}
}Install send0 MCP in VS Code CLI
$ code --add-mcp '{"name":"send0","type":"stdio","command":"npx","args":["-y","@send0/mcp"],"env":{"SEND0_API_KEY":"<YOUR_SEND0_API_KEY>"}}'Install send0 MCP in Claude Desktop
claude_desktop_config.json
{
"mcpServers": {
"send0": {
"command": "npx",
"args": [
"-y",
"@send0/mcp"
],
"env": {
"SEND0_API_KEY": "<YOUR_SEND0_API_KEY>"
}
}
}
}Install send0 MCP in Codex
$ codex mcp add send0 --env 'SEND0_API_KEY=<YOUR_SEND0_API_KEY>' -- npx -y @send0/mcpInstall send0 MCP in Codex config.toml
~/.codex/config.toml
[mcp_servers.send0] command = "npx" args = ["-y", "@send0/mcp"] [mcp_servers.send0.env] SEND0_API_KEY = "<YOUR_SEND0_API_KEY>"
Install send0 MCP in Gemini CLI
$ gemini mcp add -s user -e 'SEND0_API_KEY=<YOUR_SEND0_API_KEY>' send0 npx -- -y @send0/mcpInstall send0 MCP in Gemini settings.json
~/.gemini/settings.json
{
"mcpServers": {
"send0": {
"command": "npx",
"args": [
"-y",
"@send0/mcp"
],
"env": {
"SEND0_API_KEY": "<YOUR_SEND0_API_KEY>"
}
}
}
}send0 MCP tools 7
Detected from the READMEcreate_inboxlist_inboxeswait_for_emailsearch_messagesget_messagesend_emailreply
| create_inbox | — | |
| list_inboxes | — | |
| wait_for_email | — | |
| search_messages | — | |
| get_message | — | |
| send_email | — | |
| reply | — |
Configuration
SEND0_API_KEYRequiredSecretsend0 API key (s0_live_…), from https://app.send0.dev
SEND0_BASE_URLAPI base URL, for a self-hosted send0
SEND0_INBOX_IDDefault inbox (ibx_…) for tools that take an inbox_id
| Name | Description | |
|---|---|---|
| SEND0_API_KEY | send0 API key (s0_live_…), from https://app.send0.dev | RequiredSecret |
| SEND0_BASE_URL | API base URL, for a self-hosted send0 | |
| SEND0_INBOX_ID | Default inbox (ibx_…) for tools that take an inbox_id |
Automated checks
Ran Nov 14, 2026Full report →Passed our automated checks. That is not a security audit: read the code and give the server the narrowest access it needs. How checks work
- Source repository linked and reachablesend0-dev/send0-v2 is public and reachablegithub.com/send0-dev/send0-v2 ↗Pass
- Package names this repository as its source@send0/mcp names send0-dev/send0-v2 as sourcenpmjs.com/package/@send0/mcp ↗Pass
- Build provenance (Sigstore attestation)Sigstore attestation for @send0/mcpnpmjs.com/package/@send0/mcp/v/0.2.1#provenance ↗Pass
- Open source license (OSI)AGPL-3.0spdx.org/licenses/AGPL-3.0.html ↗Pass
- Commit or release in the last yearLast commit or release 2026-11-01github.com/send0-dev/send0-v2 ↗Pass
- OpenSSF ScorecardNot checked
- Package name not close to a popular packageNo popular package one edit away from @send0/mcpPass
- No critical advisory in the package or its dependencies100 resolved dependencies checked; no critical advisoryosv.dev ↗Pass
- No hidden instructions to the model7 tool descriptions and the README read; no override phrases, credential paths or hidden charactersPass
- Destructive tools are labelledNo tool named like delete, drop or execPass
- Remote endpoint answers the MCP handshakeHTTPS endpoint answered 401 (sign-in required)Pass
README
View on GitHub@send0/mcp
MCP server for send0. Give Claude, Cursor or any MCP client its own email inbox: sign up for things, read verification codes, and hold real email conversations.
Tools
| Tool | What it does |
|---|---|
create_inbox |
Make a new address, e.g. signup-agent@send0.email |
list_inboxes |
Inboxes this key can use |
wait_for_email |
Block until a matching email arrives; returns the one-time code and verify link already extracted |
search_messages |
Full-text search, filter by sender (*@github.com) or direction |
get_message |
Read one message (new text only by default, to save tokens) |
list_threads / get_thread |
Read whole conversations, oldest first |
send_email |
Start a new thread |
reply |
Answer in the same thread |
Email bodies are returned inside <untrusted_email> tags with a note to treat them as data, and messages flagged for prompt injection carry a visible warning. Read-only tools are annotated readOnlyHint, and sending tools openWorldHint, so clients can ask before sending.
Setup
Get an API key at https://send0.dev. A key limited to one inbox is the safest choice for an agent.
Claude Code
claude mcp add send0 --env SEND0_API_KEY=s0_live_… -- npx -y @send0/mcp
Claude Desktop / Cursor
{
"mcpServers": {
"send0": {
"command": "npx",
"args": ["-y", "@send0/mcp"],
"env": { "SEND0_API_KEY": "s0_live_…" }
}
}
}
Options
| Variable | |
|---|---|
SEND0_API_KEY |
Required |
SEND0_INBOX_ID |
Default inbox, so tools don't need inbox_id |
SEND0_BASE_URL |
For self-hosted send0 |
Use it from code
import { createSend0Server } from "@send0/mcp";
import { Send0 } from "@send0/sdk";
const server = createSend0Server({ client: new Send0(process.env.SEND0_API_KEY) });
// connect any MCP transport
License
MIT
send0 MCP questions
How do I add send0 MCP to Claude Code?
Run claude mcp add --env 'SEND0_API_KEY=<YOUR_SEND0_API_KEY>' send0 -- npx -y @send0/mcp in your terminal. Add --scope user to make it available in every project.
How do I add send0 MCP to Cursor?
Open ~/.cursor/mcp.json and add the server under mcpServers, using the Cursor config shown in the install section above.
What tools does send0 MCP provide?
It exposes 7 tools, including create_inbox, list_inboxes, wait_for_email, search_messages, get_message.
How can I use send0 with Claude Code?
You can add it using the command: claude mcp add send0 --env SEND0_API_KEY=your_key -- npx -y @send0/mcp
Can I use a specific inbox by default?
Yes, you can set the SEND0_INBOX_ID environment variable so that tools do not require an inbox_id parameter.
How does the server handle email content security?
Email bodies are returned inside <untrusted_email> tags to indicate they should be treated as data, and messages flagged for prompt injection include a warning.