Read Enginemailer subscribers, lists and campaigns; add subscribers, create and send campaigns. Hosted by usefulapi — connect from Claude, ChatGPT, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"enginemailer": {
"url": "https://enginemailer.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"enginemailer": {
"type": "http",
"url": "https://enginemailer.usefulapi.io/mcp"
}
}
}No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run these commands. The second one opens the login page:
Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
The login page asks for your Enginemailer API key.
In Enginemailer open Manage account → API Keys and copy a key (you can create a separate key for this connection and revoke it any time). The key acts on your whole account, including sending email, so use it only with an assistant you trust. The Campaign tools need a paid Enginemailer plan. Your key is used only to call the Enginemailer API on your behalf; it is never shown to anyone.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Enginemailer API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
Turn on the Enginemailer connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
enginemailer_get_subscriber | read | Get subscriber One subscriber by email: id, status and all custom field values. GET /restapi/subscriber/emsubscriber/getSubscriber. |
enginemailer_list_subscriber_categories | read | List subscriber categories The subscriber category tree: each category with its subcategories (ids, names). Use the subcategory ids when adding or updating subscribers and when assigning campaign recipients. GET /restapi/subscriber/emsubscriber/getSubCategory. |
enginemailer_list_custom_fields | read | List custom fields The subscriber custom field definitions (key, name, type). Use the keys when adding or updating subscribers. GET /restapi/subscriber/emsubscriber/getCustomField. |
enginemailer_add_subscriber | write | Add subscriber WRITE: add a subscriber to the account (optionally into subcategories, with custom field values). Only add people who consented to marketing email. Free accounts may insert 50 subscribers a day, paid accounts 10,000. POST /restapi/subscriber/emsubscriber/insertSubscriber. |
enginemailer_update_subscriber | write | Update subscriber WRITE: change an existing subscriber's subcategories and/or custom fields. subcategories_mode: append (default), remove (drop the given subcategories) or replace (the given list becomes the full list). custom_fields_mode: update_given (change only the given fields) or replace_all (default; fields not given are cleared). POST /restapi/subscriber/emsubscriber/updateSubscriber. |
enginemailer_unsubscribe_subscriber | write | Unsubscribe subscriber WRITE: unsubscribe a subscriber so they no longer receive campaigns. Reversing it needs the subscriber to opt in again in Enginemailer. GET /restapi/subscriber/emsubscriber/unSubSubscriber. |
enginemailer_save_subscriber_category | write | Create or update subscriber category WRITE: create a subscriber category (category_id 0) or update one (its id), with subcategories (subcategory_id 0 creates one). Names and descriptions max 128 characters. POST /restapi/subscriber/emsubscriber/updateCategory. |
enginemailer_list_campaigns | read | List undelivered campaigns List campaigns that have NOT been delivered yet (drafts and scheduled ones): id, name, subject, sender and schedule. Delivered campaigns are not listed by the API; use enginemailer_get_campaign_stats with a known id. Needs a paid account. GET /restapi/campaign/emcampaign/ListCampaign. |
enginemailer_get_campaign_stats | read | Get campaign delivery stats Delivery results of a DELIVERED campaign: emails sent, delivered, bounces, opens, unique opens, clicks, unique clicks, unsubscribes, spam complaints. Needs a paid account. GET /restapi/campaign/emcampaign/getcampaigndeliverystatus. |
enginemailer_list_campaign_categories | read | List campaign categories The categories that campaign recipients can be filtered by (id, name, description). Needs a paid account. GET /restapi/campaign/emcampaign/GetCategoryList. |
enginemailer_list_campaign_subcategories | read | List campaign subcategories The subcategories of one campaign category (id, name, description); use these ids in enginemailer_assign_campaign_recipients. Needs a paid account. GET /restapi/campaign/emcampaign/GetSubCategoryList. |
enginemailer_create_campaign | write | Create campaign (draft) WRITE: create a campaign DRAFT. Nothing is sent: assign recipients with enginemailer_assign_campaign_recipients, then send with enginemailer_send_campaign. The sender domain must be verified in Enginemailer; max 200 campaigns per account. Needs a paid account. POST /restapi/Campaign/EMCampaign/CreateCampaign. |
enginemailer_assign_campaign_recipients | write | Assign campaign recipients WRITE: set who a campaign will go to: all subscribers, or the subscribers in the given subcategory ids (match_type any = OR, all = AND). Does not send anything. Needs a paid account. POST /restapi/campaign/emcampaign/AssignRecipientList. |
enginemailer_send_campaign | write | Send campaign NOW WRITE, SENDS EMAIL TO CUSTOMERS NOW and cannot be undone: delivers the campaign to its assigned recipients immediately. The campaign needs at least one recipient and must not be scheduled or already delivered. Show the user the campaign and its audience and get their go-ahead first; set confirm to true only then. Needs a paid account. GET /restapi/campaign/emcampaign/SendCampaign. |
enginemailer_send_transactional_email | write | Send transactional email WRITE, SENDS ONE EMAIL NOW and cannot be undone: submits a transactional email to one recipient (plus optional CC/BCC). Needs a sender address on a verified domain; give either subject + content_html, or a template_id from the Enginemailer portal (the template supplies subject and sender name). Total message incl. attachments max 5 MB. Confirm the recipient and text with the user first; set confirm to true only then. POST /RESTAPI/V2/Submission/SendEmail. |
enginemailer_start_transactional_report_export | write | Start transactional report export Start a CSV export of the transactional email delivery report for a period (start date at most 60 days back). Returns an export id; poll it with enginemailer_check_transactional_report_export. Creates a report file only; nothing is sent. POST /RESTAPI/V2/Submission/Report/Export. |
enginemailer_check_transactional_report_export | read | Check transactional report export Status of a report export (Processing or Complete); when complete it includes the CSV download URL. POST /RESTAPI/V2/Submission/Report/CheckExport (read-only). |
enginemailer_usage_status | Usage status (free-tier meter) Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter. | |
enginemailer_request_feature | Request a missing feature Tell usefulapi that the user needs something the Enginemailer tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
enginemailer_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on Enginemailer (the free tier caps monthly usage). Plans: "monthly" — $9/month; "yearly" — $90/year (2 months free). Cancel any time: Pro then runs to the end of the paid period, so it also suits a one-time job. *A fair use limit applies. For heavy use (near Pro's limit): "plus" or "plus_yearly" — Pro+, $19/month or $190/year, unlimited tool calls (fair use limit: 100,000 a month); an existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Otherwise returns a short link to open in your browser (it opens Stripe Checkout); after payment the account upgrades automatically. Does not count against the meter. | |
enginemailer_cancel_subscription | Cancel the Pro subscription Cancel the caller's Enginemailer Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run enginemailer_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this Enginemailer server only. Subscribe with enginemailer_upgrade (it returns a Stripe Checkout link). Cancel any time with enginemailer_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running enginemailer_upgrade before then undoes the cancel. Or write to [email protected].
No. usefulapi is an independent service. It is not affiliated with or endorsed by Enginemailer. The server calls the Enginemailer API with your own Enginemailer access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your Enginemailer API key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Enginemailer API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the Enginemailer API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in Enginemailer.
Yes, if you approve it. 9 of the 17 Enginemailer tools can create or change data. The other 8 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this Enginemailer server only. Cancel any time: Pro then runs to the end of the paid period. Run enginemailer_usage_status to see how many calls you used.
Ask the AI to run enginemailer_upgrade: it returns a Stripe Checkout link. To cancel, run enginemailer_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with enginemailer_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.