JustCall
Read and manage JustCall calls, texts, contacts, phone numbers, users and webhooks.
About
JustCall 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.
- App id
io.w6w.justcall- Version
- 0.1.1
- Author
- w6w
- Licence
- MIT
- Categories
- Communication · Customer Relationship Management
Overview
JustCall is a cloud phone system and SMS/calling platform: phone numbers, agents, calls and text messages in one account. This app covers the core of a JustCall-driven workflow — read and update calls, send and read SMS, manage contacts (including DND/DNM/blacklist status), read phone numbers and their capabilities, look up and update user availability, and manage webhook subscriptions.
The API answers most reads with a paginated envelope (status, data, count, next_page_link) and a few writes with a bare {status} or a single-item data array rather than a single object — every action here follows the shape JustCall’s own OpenAPI document declares for that specific endpoint, not a single assumed shape for the whole app.
Health is tracked against JustCall’s own Statuspage, which names a genuine Developer APIs component distinct from the dashboard and calling infrastructure, plus the account’s own hourly and per-minute rate-limit headroom read from the documented X-Rate-Limit-* response headers.
Build with JustCall
Three routes to the same 21 actions. The Workflow tab is generated from JustCall'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.
Get Call
call-get Fetch data for a call: duration, direction, status, timestamps, notes and disposition.
List Calls
call-list Retrieve calls linked to the account, optionally filtered by agent, direction, type, date range and more. History is retained for the last 3 months via this endpoint.
Update Call
call-update Update the notes, disposition or rating for a completed call. Updates to an ongoing or in-progress call are not supported.
Delete Contact
contact-delete Delete a contact by id or contact_number. Send across_team as true to delete for all agents in the account.
List Contacts
contact-list Retrieve contacts in the account, optionally filtered by name, number or status.
Update Contact Status
contact-update-status Add and/or remove a contact from the DND, DNM and Blacklist lists.
Get Phone Number
phone-number-get Fetch data for a phone number, including its current availability status.
List Phone Numbers
phone-number-list Fetch the phone numbers added to the account, optionally filtered.
Check Reply
text-check-reply Check for the most recent inbound SMS from a contact, optionally scoped to a specific JustCall number.
Send SMS/MMS
text-send Send an SMS (or MMS, with media_url) from a JustCall number to a contact. Maximum 1,600 characters.
Update User Availability
user-update-availability Set a user (agent) as available or unavailable, with an optional reason.
List Webhook Subscriptions
webhook-list Retrieve every event type with any subscribed URL, or filter to one event type and see its subscribed URLs.
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 JustCall's real ids.
{
"manifestVersion": "2",
"name": "justcall-example",
"steps": [
{
"id": "call-get",
"uses": {
"app": "io.w6w.justcall",
"action": "call-get",
"connection": "conn_YOUR_CONNECTION_ID"
},
"with": {
"id": "<id>"
}
}
]
}Here are some of the things you can do
-
Get Call
readcall-get -
List Calls
searchcall-list -
Update Call
performcall-update -
Create Contact
performcontact-create -
Get Contact
readcontact-get
+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 JustCall, 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 JustCall. 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: "call-get",
payload: {
id: "<value>",
},
});
if (isActionRun(envelope)) console.log(envelope.value);npm install -g @w6w/cliw6w run conn_YOUR_CONNECTION_ID --action call-get --payload '{"id":"<value>"}'Give an AI agent JustCall — without giving it JustCall'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.justcall#call-get",
"input": {
"id": "<id>"
}
}
}
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 JustCall connections to sign
with, and refuses rather than guesses when the answer is ambiguous.
What the agent gets
Credentials it can't read
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.
A tool surface scoped to the caller
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.
A durable workflow in one call
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.
Health-aware discovery
JustCall'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. JustCall itself is MIT, and the runtime that executes it is source-available (FSL).
Health checks
JustCall declares its own checks, so its health is a property of the app rather than something the host guesses at.
JustCall platform status
Component status from status.justcall.io, including its named Developer APIs, Authorization and Webhooks components alongside the calling, SMS/MMS, dashboard, contact sync and third-party dependency groups.
Rate-limit headroom
Hourly and per-minute (burst) request headroom, read from the X-Rate-Limit-* response headers on GET /v2.1/users?per_page=1.