Frequently asked questions

Answers about installation, usage and saved content.

Is Formulix free?

The GPL client is free. The API has a Free plan with 500 insertions/month and paid plans. Current prices are provisional; you must satisfy the host editor’s licence separately.

Charged in Brazilian reais (BRL) via Mercado Pago; for other currencies, contact us. Prices are provisional.

Can the key appear in page source?

Yes: it is public and limited to your account’s domains. Never use administrator tokens. Origin is not a server secret; revoke and replace the key if it is abused.

Do previews use my allowance?

They do not use insertions, but they are recorded and subject to the per-minute limit. Confirming an edit counts again. Word paste into a document counts per converted equation.

Why am I getting 403?

Check the editor domain sent in Origin, not just the student-facing page’s domain, and the account owning the key. A registered domain covers subdomains. Allow about 5 seconds after configuration changes and inspect the browser’s Network tab.

Why am I getting 402 on localhost?

Development has its own default ceiling of 300 insertions/month/account. It does not use your plan allowance, but it is still limited. Changing keys within the same account does not reset the counter.

What happens when my plan expires?

There is a 3-day grace period, then Free limits apply. Saved HTML stays readable; the API is needed for new insertions. Preserving PNG files is your platform’s responsibility.

Does payment renew automatically?

The implemented flow buys 1 or 12 months upfront through Mercado Pago Checkout Pro. This code does not implement automatic recurring renewal. An approved renewal of the same still-valid plan extends its term.

Does Word paste work in every editor?

This has not been validated. The OMML/RTF clipboard path is specific to TinyMCE and depends on the browser. There is no native Microsoft Word add-in in this release.

Are the integrations listed in plugin directories?

No. Moodle, WordPress, CKEditor 5, Drupal and Tiptap are alpha and distributed as local build artifacts.

Does the server store my formulas?

The reviewed routes process content in memory without writing it to SQLite. They store counters. Logs and infrastructure need separate assessment: see the privacy policy.

What notation does the English interface use?

Decimal points, sin/tan, ordered pairs (x, y), x₁/x₂ and long division. The interface uses GCD; UK teachers may call this HCF. “Rule of three” handles direct or inverse proportion.