WLI: Scheduler endpoint — example on a custom backend proxy

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🔗Creating a new scheduled post by using the API

You can show the Planner via an iframe or creating an automation using the API only.

Endpoint overview

This guide walks through a real working example of creating a scheduled post in Metricool from your own web app, using the POST /v2/scheduler/posts endpoint.

It follows the same client → backend proxy → Metricool call flow described in the first reference below; this article applies that architecture to one concrete case: scheduling a post.

The example is split into three parts, mirroring a typical White Label Integration (WLI) setup:

A form in your frontend where the end user fills in the post details. Unlike the create new brand button, discussed before (here), this one cannot be a button as it has different parameters attached to the body call, as you will see next.
A backend proxy that holds your Metricool API credentials and forwards the request.

This example uses plain HTML/JavaScript and a Python http.server proxy (standard library only, no frameworks) so it can be adapted to any stack.

— Prerequisites —

You'll need three values from your Metricool account:

Value	Where to find it
`userToken`	Metricool → Menu → Account Settings → API section → "REST API Access token"
`userId`	Your Metricool user identifier
`blogId`	The brand/profile identifier (visible in the browser URL when using that brand in Metricool)

All three are mandatory on every API call. userId and blogId are sent as query parameters; userToken is sent in the X-Mc-Auth request header (as we discussed here).

— Understand the endpoint —

POST https://app.metricool.com/api/v2/scheduler/posts?blogId={blogId}&userId={userId}

Header	Value
`Content-Type`	`application/json`
`X-Mc-Auth`	your `userToken`

Minimum required body fields:

Field	Type	Description
`publicationDate.dateTime`	string	ISO local date-time, no timezone offset in the string (e.g. `2026-08-01T10:00:00`). Must be in the future.
`text`	string	The post's text content
`providers`	array	Target networks, e.g. `[{ "network": "facebook" }]`. Supported values: `facebook`, `instagram`, `twitter`, `linkedin`, `tiktok`, `pinterest`, `youtube`, `gmb`, among others.

Commonly used optional fields:

Field	Type	Description
`autoPublish`	boolean	`true` publishes directly, `false` leaves it pending
`draft`	boolean	`true` saves it as a draft
`creatorUserMail`	string	Email of the user creating the post
`media`	array of strings	See note on media below
`facebookData`, `instagramData`, `twitterData`, ...	object	Network-specific options (e.g. `{"type": "POST"}` for Facebook)
`publicationDate.timezone`	string	IANA timezone of the brand/user (e.g. `Europe/Madrid`). If none is added, it is set according to the account's timezone.

Media warning:

If the post includes an image or video, set as true the parameter saveExternalMediaFiles: true; as you have in the Example body below.

Example body:

{
  "publicationDate": {
    "dateTime": "2026-08-01T10:00:00",
    "timezone": "Europe/Madrid"
  },
  "text": "Yeah, team! This is a scheduled post test for White Label Integration.",
  "providers": [
    { "network": "facebook" }
  ],
  "autoPublish": true,
  "draft": false,
  "shortener": false,
  "saveExternalMediaFiles": false,
  "creatorUserMail": "[email protected]"
}

— Troubleshooting —

Table C

Symptom	Cause	Fix
`401 Unauthorized`	Missing access key	Add the access token (`userToken`) and the userId into the request call
`403 Forbidden` on an `OPTIONS` request	Arbitrary browser calling Metricool's API directly triggers a CORS preflight, which Metricool rejects	Route the call through your own backend proxy (see Step 2)
`400 Bad Request`	`publicationDate.dateTime` is in the past, or a required field is missing	Make sure the date/time is in the future and that `publicationDate`, `text`, and `providers` are present
`Unexpected token '<' ... is not valid JSON` in the browser console	Client code called `response.json()` on an error response that wasn't actually JSON	Read the response with `response.text()` first, then attempt to parse it (see Step 3)
Token visible in page source	`userToken` was placed in client-side HTML/JS	Move all credentials to the backend proxy and read them from environment variables

Additional Resources

✅WLI: Integration Architecture (here)

✅WLI: Setting up the sample Backend Proxy (here)
✅WLI: Checking our API (here)

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