@e2a/mcp-server

@e2a/mcp-server

Model Context Protocol server for e2a — gives any MCP-aware AI agent its own email inbox to send, receive, reply, and (optionally) review held outbound mail before it ships.

Works with Google ADK, LangChain, OpenAI Agents SDK, Claude Desktop, Cursor, Cline, and any other MCP host.

Install

No install — invoke directly with npx:

npx -y @e2a/mcp-server

Requires Node 18+. The server speaks MCP over stdio.

Configuration

Set these in the MCP host's environment block.

Variable	Required	Default	Description
E2A_API_KEY	yes	—	API key from the e2a dashboard
E2A_AGENT_EMAIL	no	—	Default agent inbox. Scopes the tools so the LLM doesn't have to repeat the address.
E2A_BASE_URL	no	https://e2a.dev	Self-hosted deployment URL

Quick start

Google ADK (Python)

from google.adk.agents import Agent
from google.adk.tools.mcp_tool import McpToolset
from google.adk.tools.mcp_tool.mcp_session_manager import StdioConnectionParams
from mcp import StdioServerParameters

root_agent = Agent(
    model="gemini-flash-latest",
    name="e2a_agent",
    instruction="Help the user manage their email. Reply to threads with `reply_to_message` to preserve threading headers.",
    tools=[
        McpToolset(
            connection_params=StdioConnectionParams(
                server_params=StdioServerParameters(
                    command="npx",
                    args=["-y", "@e2a/mcp-server"],
                    env={
                        "E2A_API_KEY": "YOUR_E2A_API_KEY",
                        "E2A_AGENT_EMAIL": "[e-mail]",
                    },
                ),
                timeout=30,
            ),
        ),
    ],
)

LangChain (Python)

Using langchain-mcp-adapters:

from langchain_mcp_adapters.client import MultiServerMCPClient
from langgraph.prebuilt import create_react_agent

client = MultiServerMCPClient({
    "e2a": {
        "command": "npx",
        "args": ["-y", "@e2a/mcp-server"],
        "transport": "stdio",
        "env": {
            "E2A_API_KEY": "YOUR_E2A_API_KEY",
            "E2A_AGENT_EMAIL": "[e-mail]",
        },
    },
})

tools = await client.get_tools()
agent = create_react_agent("anthropic:claude-sonnet-4-6", tools)

OpenAI Agents SDK (Python)

from agents import Agent, Runner
from agents.mcp import MCPServerStdio

async with MCPServerStdio(
    params={
        "command": "npx",
        "args": ["-y", "@e2a/mcp-server"],
        "env": {
            "E2A_API_KEY": "YOUR_E2A_API_KEY",
            "E2A_AGENT_EMAIL": "[e-mail]",
        },
    },
) as e2a:
    agent = Agent(name="e2a_agent", mcp_servers=[e2a])
    result = await Runner.run(agent, "Reply to the latest unread email politely.")

Claude Desktop / Cline / Cursor

Add to the MCP config (claude_desktop_config.json, cline_mcp_settings.json, etc.):

{
  "mcpServers": {
    "e2a": {
      "command": "npx",
      "args": ["-y", "@e2a/mcp-server"],
      "env": {
        "E2A_API_KEY": "YOUR_E2A_API_KEY",
        "E2A_AGENT_EMAIL": "[e-mail]"
      }
    }
  }
}

Tools

Identity

Tool	Description
whoami	Get the default agent's full record (requires E2A_AGENT_EMAIL).
list_agents	List every agent inbox owned by the authenticated user.
create_agent	Register a new inbox using a slug on the shared domain. Defaults to local mode — no webhook required. See note below for cloud mode.

Cloud-mode agents must verify webhook signatures. When you create an agent with agent_mode: "cloud", e2a HMAC-signs every webhook delivery against your account's webhook signing secret (E2A_WEBHOOK_SECRET, shown in the e2a dashboard). Your webhook handler must verify the signature on every request — the e2a SDK exposes parseWebhook(body, secret) which parses and verifies in one call. Local-mode agents (the default) avoid this entirely by polling via list_messages.

Messages

Tool	Description
send_email	Send a new email. When the agent has HITL enabled, the message is held and returns status: pending_approval instead of sent.
reply_to_message	Reply to an inbound message. Preserves In-Reply-To / References for thread continuity.
list_messages	List inbound mail. Filter by status (unread / read / all), paginate with page_size + token.
get_message	Fetch full body, headers, and attachment metadata for one message.

Human-in-the-loop approval

Tool	Description
list_pending_messages	List outbound mail awaiting human approval, soonest-expiring first.
get_pending_message	Get the full draft (subject, recipients, body) of a pending message.
approve_pending_message	Send a held message, optionally with reviewer edits (subject / body / recipients).
reject_pending_message	Discard a held message; the optional reason is stored for audit.

Links

• e2a docs
• Source
• Issues
• Model Context Protocol

License

Apache-2.0