# e2a MCP tool for ADK Supported in ADKPythonTypeScript The [e2a MCP Server](https://github.com/tokencanopy/e2a/tree/main/mcp) connects your ADK agent to [e2a](https://e2a.dev), an authenticated email gateway built for AI agents. This integration gives your agent its own email inbox to send, receive, and reply to messages using natural language, with SPF/DKIM/DMARC verification on inbound mail and an optional human review hold on outbound messages. The server is hosted at `https://api.e2a.dev/mcp` and speaks Streamable HTTP — there is nothing to install or run locally. ## Use cases - **Give agents their own inboxes**: Provision dedicated email addresses (e.g. `support-bot@your-domain.com`) and let agents send and receive mail just like a teammate. - **Authenticated inbound**: Every incoming message carries SPF, DKIM, and DMARC evidence, so your agent can tell whether the sender is who they claim to be before acting on the content. - **Human-in-the-loop review**: Turn on a review hold and outbound messages are parked as `pending_review` until a human approves them — optionally with edits to the subject, body, or recipients before sending. - **Automate threaded conversations**: Reply with `In-Reply-To` and `References` headers preserved, so threads stay intact across multiple turns in the recipient's mail client. ## Prerequisites - A free [e2a account](https://e2a.dev) and an API key from the dashboard ## Use with agent ```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 ( StreamableHTTPConnectionParams, ) E2A_API_KEY = "YOUR_E2A_API_KEY" root_agent = Agent( model="gemini-flash-latest", name="e2a_agent", instruction=( "You manage email through the e2a tools. Call whoami once to " "learn your identity and inbox address. Use list_messages and " "get_message to read; use reply_to_message when replying to an " "existing thread (it preserves In-Reply-To and References), and " "send_message only to start a new thread. Both 'accepted' and " "'pending_review' are successful outcomes — never re-send after " "either one." ), tools=[ McpToolset( connection_params=StreamableHTTPConnectionParams( url="https://api.e2a.dev/mcp", headers={"Authorization": f"Bearer {E2A_API_KEY}"}, timeout=30, ), ) ], ) ``` ```typescript import { LlmAgent, MCPToolset } from "@google/adk"; const E2A_API_KEY = "YOUR_E2A_API_KEY"; const rootAgent = new LlmAgent({ model: "gemini-flash-latest", name: "e2a_agent", instruction: "You manage email through the e2a tools. Call whoami once to " + "learn your identity and inbox address. Use list_messages and " + "get_message to read; use reply_to_message when replying to an " + "existing thread (it preserves In-Reply-To and References), and " + "send_message only to start a new thread. Both 'accepted' and " + "'pending_review' are successful outcomes — never re-send after " + "either one.", tools: [ new MCPToolset({ type: "StreamableHTTPConnectionParams", url: "https://api.e2a.dev/mcp", transportOptions: { requestInit: { headers: { Authorization: `Bearer ${E2A_API_KEY}`, }, }, }, }), ], }); export { rootAgent }; ``` For production, pair the toolset with the e2a SDK The MCP toolset hands the inbox to the model. Keep the deterministic parts — verifying webhook signatures, handling at-least-once delivery, sending idempotently — in application code with the [Python](https://pypi.org/project/e2a/) or [TypeScript](https://www.npmjs.com/package/@e2a/sdk) SDK. The ADK webhook example below is a complete working version of that shape. ## Available tools The hosted server exposes 60+ tools; call `tools/list` against the endpoint for the authoritative set. Which ones you see depends on your key: an **agent-scoped** key (`e2a_agt_…`) — recommended for a deployed agent — sees only the runtime tools, while an **account-scoped** key (`e2a_acct_…`) also sees the admin tools below. ### Runtime — inbox tools | Tool | Description | | ----------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | `whoami` | Return the authenticated identity: user, credential scope, plan and usage limits, plus `agent_email` for an agent-scoped credential | | `get_agent` | Fetch one agent's full record | | `list_messages` | List inbox or sent mail with `direction`, `read_status`, search filters, and cursor pagination | | `get_message` | Full body, headers, attachment metadata, and SPF/DKIM/DMARC evidence for one message | | `get_message_lifecycle` | Reconstructed delivery history for one message | | `get_attachment` | Attachment metadata, or the bytes inline with `inline: true` | | `send_message` | Send a new email; returns `accepted`, or `pending_review` when a review hold catches it — both are success, neither should be retried | | `reply_to_message` | Reply in-thread; preserves `In-Reply-To` and `References` | | `forward_message` | Forward a message to new recipients | | `list_conversations` / `get_conversation` | Browse threads rather than individual messages | | `update_message_labels` | Add or remove labels on a message | | `delete_message` / `restore_message` | Soft-delete to trash, and restore | ### Admin — provisioning and setup | Tool | Description | | ----------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- | | `list_agents`, `create_agent`, `update_agent`, `delete_agent`, `restore_agent` | Manage agent inboxes | | `get_protection`, `update_protection` | Per-agent screening and review-hold configuration | | `list_domains`, `register_domain`, `get_domain`, `verify_domain`, `delete_domain` | Custom domain registration and DNS verification | | `list_reviews`, `get_review`, `approve_review`, `reject_review` | Work the human review queue | | `list_webhooks`, `create_webhook`, `update_webhook`, `delete_webhook`, `rotate_webhook_secret`, `test_webhook`, `list_webhook_deliveries` | Webhook subscriptions and delivery history | | `list_events`, `get_event`, `redeliver_event` | Event log and replay | | `list_templates`, `create_template`, `update_template`, `delete_template`, `validate_template` | Server-side email templates (beta) | | `list_api_keys`, `create_api_key`, `delete_api_key` | API key management | ## Configuration The hosted endpoint needs no environment variables beyond your API key, which ADK passes in the `Authorization` header shown above. To use a self-hosted e2a deployment, change the `url` to that deployment's `/mcp` endpoint. Interactive MCP clients can add `https://api.e2a.dev/mcp` as an OAuth 2.1 connector instead of pasting a key. To receive mail, poll `list_messages`, open a WebSocket with the SDK's `listen()` (no public URL required), or subscribe an HTTPS endpoint with `create_webhook`. ## Additional resources - [e2a MCP Server source](https://github.com/tokencanopy/e2a/tree/main/mcp) - [Runnable ADK example](https://github.com/tokencanopy/e2a/tree/main/mcp/examples/adk) - [ADK webhook example](https://github.com/tokencanopy/e2a/tree/main/examples/adk-cloud-webhook) - [e2a documentation](https://e2a.dev)