Send transactional email and manage templates, tags, rejects, and whitelist entries via Mandrill (Mailchimp Transactional).
Mandrill ships in the w6w first-party pack. It declares 17 actions, 2 health checks, and the host runs its code in a sandbox that never sees the credential.
io.w6w.mandrillMandrill (Mailchimp Transactional) sends transactional email — receipts, password resets, notifications — and this app covers both sending and the account-level management around it: sending a message directly, sending from a pre-built template, and reading account info and the senders a domain has verified. It is built for workflows that need to send email as part of a larger process rather than through Mailchimp’s own marketing-campaign tools.
Templates can be listed, created, updated, and deleted, so a workflow can manage the templates it sends from as well as use them. Deliverability tooling is covered too: tags can be listed and their stats read for reporting, and both the reject list — addresses that bounced or complained — and the whitelist can be read and managed directly, for clearing a wrongly-rejected address or exempting one from Mandrill’s own filtering.
Three routes to the same 17 actions. The Workflow tab is generated from Mandrill's own manifest and carries its real ids, so it is copy-pasteable; the Code and CLI examples are the same call for any action on any app, so every app-specific value in them is a blank you fill in.
add-whitelist Add an email to the rejection whitelist; removes any matching blacklist entry automatically (POST /whitelists/add.json).
delete-reject Remove an email from the rejection denylist (POST /rejects/delete.json).
delete-tag Permanently delete a tag, removing it from any messages it was applied to and deleting its stats (POST /tags/delete.json).
delete-whitelist Remove an email from the rejection whitelist (POST /whitelists/delete.json).
get-tag-info Return detailed stats for a single tag, including recent-period aggregates (POST /tags/info.json).
list-senders Return the senders that have tried to use this account, verified and unverified (POST /users/senders.json).
list-templates Return all templates available to this account (POST /templates/list.json).
list-whitelist Return the email rejection whitelist, up to 1000 results (POST /whitelists/list.json).
send-message Send a transactional email via Mandrill (POST /messages/send.json). Provide `html` or `text`.
send-template-message Send a transactional email via an existing Mandrill template (POST /messages/send-template.json).
update-template Update the code and metadata for an existing template (POST /templates/update.json).
A workflow step names the app and the action, and the editor fills in the
connection when you pick one. This is the Step shape from the
workflow spec, carrying Mandrill's real ids.
{
"manifestVersion": "2",
"name": "mandrill-example",
"steps": [
{
"id": "add-reject",
"uses": {
"app": "io.w6w.mandrill",
"action": "add-reject",
"connection": "conn_YOUR_CONNECTION_ID"
},
"with": {
"email": "<email>"
}
}
]
}add-reject add-template add-whitelist get-tag-info get-user-info +12 more actions available
Every app-specific value here is a blank you have to fill in. An
app action is reached through the connection that authenticates it, so the
address is a connection id, not the app id — and connections belong to your account,
so a public page cannot know yours. Create one for Mandrill, then fill in
the three blanks: conn_YOUR_CONNECTION_ID, the action key, and the
parameters that action declares. The call itself is real — the shape is transcribed
from the studio's own snippet builder, which prints the same kind of blanks — but
nothing in it is specific to Mandrill. The Workflow tab is where this app's
real ids are.
npm install @w6w/sdkyarn add @w6w/sdkpnpm add @w6w/sdkdeno add npm:@w6w/sdkimport { W6wClient, isActionRun } from "@w6w/sdk";
// Reads W6W_BASE_URL and W6W_TOKEN from the environment when omitted.
const client = new W6wClient();
const envelope = await client.run({
urn: "conn_YOUR_CONNECTION_ID",
action: "send-message",
payload: {
fromEmail: "<value>",
// fromName: "<value>",
to: "<value>",
// cc: "<value>",
// bcc: "<value>",
subject: "<value>",
// html: "<value>",
// text: "<value>",
// important: "<value>",
// trackOpens: "<value>",
// trackClicks: "<value>",
// autoText: "<value>",
// inlineCss: "<value>",
// tags: "<value>",
// headers: "<value>",
// globalMergeVars: "<value>",
// mergeVars: "<value>",
// attachments: "<value>",
// subaccount: "<value>",
// async: "<value>",
// ipPool: "<value>",
// sendAt: "<value>",
},
});
if (isActionRun(envelope)) console.log(envelope.value); npm install -g @w6w/cli w6w run conn_YOUR_CONNECTION_ID --action send-message --payload '{"fromEmail":"<value>","to":"<value>","subject":"<value>"}' Give an AI agent Mandrill — without giving it Mandrill's credentials. One MCP endpoint exposes every app, function and workflow the caller is entitled to, as tools it can discover and run. Access is granted per team while we onboard.
One tool call{
"name": "w6w_invoke",
"arguments": {
"ref": "app:io.w6w.mandrill#add-reject",
"input": {
"email": "<email>"
}
}
}
Every tool names its target with a single ref. The
app: form above doesn't name a connection at all — the
host resolves which of the caller's Mandrill connections to sign
with, and refuses rather than guesses when the answer is ambiguous.
The token is attached host-side, at the moment of the call. It is never a tool argument, never in the model's context, and never in a transcript — so a prompt injection has nothing to exfiltrate.
Tools are derived per end user from what that person has actually connected and is entitled to — not one shared bot identity carrying the union of everyone's access.
Multi-step work runs on the workflow engine and returns a run handle the agent can poll — retries, branching and state survive the conversation that started them.
Mandrill's declared health checks are on the surface too, so an agent can tell "the vendor is down" from "your credential expired" before it burns a retry on either.
The MCP surface is part of the hosted platform. Mandrill itself is MIT, and the runtime that executes it is source-available (FSL).
Mandrill declares its own checks, so its health is a property of the app rather than something the host guesses at.
Reads `hourly_quota` and `backlog` off POST /users/info.json. A nonzero backlog means Mandrill is currently queuing mail because the account is over its hourly or monthly quota.