Terms of use

The service

Fouro provides access to GPT-4o through OpenRouter, along with optional saved conversations, optional memory, usage limits, and subscription features. You are responsible for your account and for activity performed through it. The service is not intended for children under 13.

Fouro is an independent service and is not affiliated with or endorsed by OpenAI. It uses the GPT-4o API model but does not reproduce ChatGPT's private prompts, routing, tools, or complete product experience.

For signed-in accounts, Fouro may suggest a small number of useful, lasting, non-sensitive details from chat so future conversations can have continuity. A suggestion is not a saved memory unless you approve it. Each account can keep up to 20 memories. Fouro does not silently replace one when the limit is reached. You can review, edit, or delete those memories at any time from Memory in the sidebar. Guest chats do not create Memory.

AI provider permission

Before the first guest or signed-in chat, Fouro asks you to allow the prompt and recent conversation context to be processed by OpenRouter and its upstream GPT-4o provider, OpenAI. Signed-in requests may also include relevant Memory you approved, and Pro requests may include your AI name and custom instructions. If you decline, Fouro does not send the message and chat remains unavailable. You can change or revoke this choice at any time; revocation applies to future requests.

AI output

AI responses can be incomplete, inaccurate, or inappropriate. Verify important information and do not rely on Fouro as a substitute for professional medical, legal, financial, or other expert advice. You remain responsible for how you use prompts and outputs. Fouro can support personal conversation and reflection, but it is an AI service—not a human friend, therapist, or emergency service.

Plans and billing

Signed-out visitors currently receive up to 5 guest requests per UTC day and 10 per UTC month for each signed browser installation. Guest chats are not saved to conversation history or Memory. A guest request counts once Fouro begins returning an answer. Signing up does not transfer the guest allowance or import guest chat history. Tolerant pseudonymous network safeguards may limit repeated browser resets while allowing normal shared-network use.

Free accounts currently include up to 10 chat requests per UTC day and 100 per UTC month. A request counts once Fouro begins returning an answer. Pseudonymous browser and network safeguards may also limit coordinated account rotation, while allowing normal shared-device and shared-network use. Fouro Pro is $25 USD per month, removes the Free plan's daily and monthly product chat-count limits, and lets an active subscriber set an account-scoped AI name and custom instructions for signed-in chats. Eligible accounts can receive one introductory 7-day free trial. A payment method is required, the charge at the start of the trial is $0, and Pro becomes available when checkout completes. Unless you cancel before the trial ends, Pro automatically renews at $25 USD per month and continues to renew monthly until canceled. You can manage renewal from Stripe's billing portal by selecting Billing & subscription. Canceling there schedules cancellation at the end of the current trial or paid billing period, and Stripe lets you resume renewal before that date. Pro remains available until that period ends. Accounts that have started a trial or subscription are not eligible for another introductory trial. You can also review invoices and update payment details there. Fouro may still apply operational request, token, storage, and service-wide safety ceilings to prevent abuse, control provider costs, and keep the service available; these safeguards are separate from the Free plan's daily and monthly allowances. Stripe may email receipts, invoice PDFs, renewal reminders, and payment-related notices to your verified account address. Cancellation takes effect according to the billing period shown by Stripe. Taxes and any refund rights depend on the checkout terms and applicable law.

On iPhone, Fouro Pro may also be purchased as an auto-renewable subscription through Apple using the localized price, billing period, and introductory-offer terms shown by the App Store before purchase. Apple charges your Apple Account and the subscription renews automatically unless canceled through Apple at least 24 hours before the current period ends. Apple handles payment, cancellation, and applicable refund decisions for Apple-billed purchases. A verified active Fouro Pro entitlement is recognized on web and iPhone for the same Fouro account. Do not purchase through both Apple and Stripe; Fouro blocks a new purchase when it can verify that Pro is already active.

Acceptable use

Do not use Fouro to break the law, violate another person's rights, distribute malware, abuse or disrupt the service, bypass usage limits or access controls, or attempt unauthorized access to accounts, systems, or data. You must have the rights needed to submit any content you provide.

Availability and responsibility

Fouro may change, suspend, or discontinue features and may restrict access needed to protect users or the service. The service is provided on an as-available basis to the extent permitted by law. Fouro is not responsible for losses caused by reliance on AI output or events outside its reasonable control. Rights that cannot legally be limited remain unaffected.

Saved chat capacity is bounded. If an account reaches its storage ceiling, Fouro may ask you to delete older conversations before saving more; existing saved chats are not silently pruned by that limit.

Changes

These terms may be updated as Fouro changes. Continued use after updated terms take effect means you accept them. Material changes will be identified by updating the date above or by an in-product notice where appropriate.