Manage SimpleLogin from your MCP client.

Independent integration for SimpleLogin

simplelogin-mcp is an independent, open-source project. It is not an official SimpleLogin or Proton AG product, service, or MCP implementation, and it is not affiliated with, endorsed by, or sponsored by SimpleLogin or Proton AG.

Looking for SimpleLogin’s official service? Visit SimpleLogin.

27 catalog-backed tools

Aliases, contacts, mailboxes, custom domains, and account settings are documented from the same source as the server.

Some reverse-alias, additional-mailbox, and custom-domain capabilities depend on your SimpleLogin plan.

See all 27 tools

Local by default

Local stdio opens no listener. Direct Node.js — Streamable HTTP binds to loopback unless you deliberately configure a wider boundary.

API keys stay out of MCP messages

The server reads SL_API_KEY from its environment and never includes it in MCP requests or results. Do not put the key in prompts. When HTTP authentication is enabled, the client sends a separate server token only to simplelogin-mcp.

Guarded permanent changes

Tools that can stop delivery or delete data are labeled Destructive. Permanent deletion requires confirm: true; mailbox deletion also requires an explicit transfer-or-delete decision for its aliases.

Let your MCP client create an alias for you

Once simplelogin-mcp is connected, this example creates one real random alias in your SimpleLogin account. It uses your account’s default alias style, so you do not need to choose an address or configure any inputs.

Alias creation example prompt

Can you create a new random SimpleLogin alias for me?

1. Review the proposed call. Confirm that the client proposes alias_create_random. It is a write action that creates one persistent alias; this prompt requires no inputs.

2. Create the alias. simplelogin-mcp asks SimpleLogin to generate one address using your account’s default alias style and routing.

3. Use the new address. The client shows the created alias so you can copy it into a signup. The address also appears in your SimpleLogin account.

Pick your MCP client

The site documents local stdio recipes for all five named clients. See the current compatibility evidence for retained test results, unavailable routes, scope, and limitations.

First time connecting? Create a dedicated SimpleLogin API key before configuring your client.

CodexLocal stdio through the shared TOML configuration.

Claude CodeLocal stdio through a project-scoped configuration.

Claude DesktopLocal stdio through the desktop client configuration.

VS CodeLocal stdio through the user-profile configuration.

OpenCodeLocal stdio through an environment-backed configuration.

All compatibility evidenceSee the review levels, current evidence, transport requirements, and current limitations.

Need another client or deployment route? Open the complete client setup guide, use the generic transport requirements, or choose a different deployment shape.

Protect both credentials

SL_API_KEY grants full control of your SimpleLogin account. MCP_AUTH_TOKEN is a separate credential that protects HTTP access to this server. The startup guard normally requires it for Docker and every non-loopback bind; bypassing that guard requires the explicit unsafe override. Supported public or LAN HTTP deployments keep the token and belong behind TLS. Read the complete security model.

Useful by design

Create and tune aliases

Find an alias, create a random or custom one, update its routing, then explicitly enable or disable it.

alias_list → alias_create_random → alias_update → alias_set_enabled

Review recent alias activity

Inspect one alias, then page through activity metadata for recent forwards, replies, blocks, and bounces. Message bodies are not read.

alias_get → alias_activity_list

Create a reverse alias for sending

Create or reuse a reverse alias for a recipient. Send the actual message from a mailbox that owns the alias; simplelogin-mcp does not compose or send email.

contact_list → contact_create

Maintain account routing

Review mailbox verification, inspect custom domains, and review or change supported account-wide alias settings.

mailbox_list → custom_domain_list → settings_get → settings_update

Follow the workflow guide

One canonical, searchable tool catalog

Search every supported tool by name, purpose, input, category, or behavior. Each result explains what the tool does, what it needs, whether it changes account state, and what it returns. The reference stays current because it reads from the same catalog and schemas used by the server.

MCP request

MCP method: tools/list

27 tools loaded from the project catalog

Aliases

10 alias_list, alias_get, alias_activity_list, alias_create_random, …

Contacts

4 contact_list, contact_create, contact_set_blocked, contact_delete

Mailboxes

4 mailbox_list, mailbox_create, mailbox_update, mailbox_delete

Custom domains

3 custom_domain_list, custom_domain_update, custom_domain_trash_list

Account

6 account_get_info, account_get_stats, notification_list, notification_mark_read, …

Generated from the same catalog as the server. It contains no credentials or account data.

Browse all 27 tools

Know when to use it

Use simplelogin-mcp for reviewable alias workflows from a compatible MCP client. Use SimpleLogin directly for sign-in, MFA, billing, account security, API-key creation, DNS verification, or any action you prefer to inspect and complete in the official interface.

Security & DataFollow requests, credentials, and account data across every trust boundary.

ConfigurationReview every environment setting and its safe default.

TroubleshootingDiagnose Local stdio, Streamable HTTP, Docker Compose, and upstream API failures.

FAQUnderstand project scope, privacy, plans, and when to use SimpleLogin directly.