invalid_url

What it means

invalid_url is a validation error. The Platform API returns it with HTTP 400 when it will not accept the webhook endpoint URL you supplied. You can hit it by calling POST /api/platform/v1/subscriptions, or by adding an endpoint in the console.

The URL is refused when it is not https on port 443, when it points at loopback or a private range, when it is a bare IP address, or when it carries credentials in the form user:password. The response body contains an error object with code, message and hint. The code is invalid_url. The message and hint help a person read the failure. Codes are stable, so branch on code rather than message text.

Why you are seeing it

You see invalid_url because the endpoint URL does not meet the rules the platform applies to webhook endpoints. Typical causes are an http:// URL, an https:// URL on a port other than 443, a host in a private range, a loopback host, a bare IP address, or a URL that includes user:password.

The same rules apply when you add an endpoint in the console. A URL that the API refuses at POST /api/platform/v1/subscriptions will also be refused in the console form.

How to fix it

Use a public https:// hostname on port 443 with no user:password in the URL. If the endpoint currently uses http://, switch to https://. If it uses a port other than 443, move it to 443. If the host is loopback, in a private range, or written as a bare IP address, use a public hostname instead.

Then retry POST /api/platform/v1/subscriptions or save the endpoint again in the console. Do not retry the unchanged request; a 400 validation failure will not clear by itself. If invalid_url comes back, re-check the https requirement, port, host type and credentials.

Handling it in code

Read the error.code field in the response. Compare it with invalid_url and do not parse the message to decide what happened; the code is stable, while messages can change. Log message and hint for the person who fixes the endpoint configuration.

Treat invalid_url as non-retryable until the URL changes. Check the endpoint URL before calling POST /api/platform/v1/subscriptions, and reject configuration that is not https on port 443, uses loopback or a private range, is a bare IP address, or contains user:password. After the configuration is corrected, send a new request.

If your code handles several webhook errors, keep invalid_url separate from endpoint_limit and invalid_topic. They are related codes, not the same condition; match each code on its own.