Send transactional email, track events, and manage contacts and campaigns in Loops.
Loops ships in the w6w first-party pack. It declares 21 actions, 2 health checks, and the host runs its code in a sandbox that never sees the credential.
io.w6w.loopsLoops is an email platform built around triggered sends, and this app is how a workflow talks to it: send a transactional email or fire an event that can kick off a Loops-side automation, and manage the contacts, mailing lists, segments and campaigns those sends depend on.
Loops keeps template design and audience logic inside its own editor — there’s no send-arbitrary-HTML endpoint — so this app reads and triggers what’s already built there rather than authoring new templates. Contact writes distinguish creating (which fails if the contact already exists) from updating (which upserts), and both sending actions can be made safely retryable by keying each send to the workflow step that made it, so a retried step never sends the same email twice.
Beyond sending, this app reads campaigns, workflows, mailing lists and audience segments, manages custom contact properties, and checks or lifts a suppression when a message needs to reach an address that previously bounced. It does not build emails or workflows themselves, or handle asset uploads — those stay in the Loops editor.
Three routes to the same 21 actions. The Workflow tab is generated from Loops'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.
contact-create Add a new contact. Fails if the email is already known — use Update to upsert.
contact-delete Permanently delete a contact and their history. Unsubscribing is usually what is meant.
contact-property-create Define a custom contact property so contact writes may set it.
contact-suppression-get Find out whether an address is suppressed after a bounce or complaint.
contact-suppression-remove Allow sending to an address Loops suppressed after a bounce or complaint.
event-pattern-get Look up an event by name to see whether Loops knows it and what it carries.
event-pattern-list List the event names Loops has seen, which is what workflow triggers match on.
mailing-list-list List mailing lists — the ids contact writes and events subscribe people to.
transactional-get Retrieve one transactional template, including whether it is published.
transactional-list List transactional templates, all of them or only the published ones.
transactional-send Send a published transactional template to one address.
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 Loops's real ids.
{
"manifestVersion": "2",
"name": "loops-example",
"steps": [
{
"id": "campaign-get",
"uses": {
"app": "io.w6w.loops",
"action": "campaign-get",
"connection": "conn_YOUR_CONNECTION_ID"
},
"with": {
"campaignId": "<campaignId>"
}
}
]
}campaign-get audience-segment-list campaign-list contact-create contact-find +16 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 Loops, 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 Loops. 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: "campaign-get",
payload: {
campaignId: "<value>",
},
});
if (isActionRun(envelope)) console.log(envelope.value); npm install -g @w6w/cli w6w run conn_YOUR_CONNECTION_ID --action campaign-get --payload '{"campaignId":"<value>"}' Give an AI agent Loops — without giving it Loops'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.loops#campaign-get",
"input": {
"campaignId": "<campaignId>"
}
}
}
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 Loops 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.
Loops'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. Loops itself is MIT, and the runtime that executes it is source-available (FSL).
Loops declares its own checks, so its health is a property of the app rather than something the host guesses at.
The API, transactional and campaign components on Loops' own status page. Unauthenticated and unsigned.