1. Acceptance of these Terms
These Terms of Use ("Terms") govern access to and use of the Stac platform, dashboard, API, documentation, and related services (together, the "Service"), operated by STAC INFRAESTRUTURA DE TECNOLOGIA LTDA, registered under CNPJ 68.403.514/0001-21, with address at Av. Anita Garibaldi, 850, Conj 312, Andar 03, Cond Infinity Prime Office, Bloco Torre 02 B, Cabral, Curitiba - PR, CEP 80.540-400 ("Stac", "we", "us").
By creating an account, accessing the Service, or using an API key, you agree to these Terms. If you are entering into these Terms on behalf of a company or other legal entity, you represent that you have authority to bind that entity, and "you" refers to that entity.
If you do not agree with these Terms, do not use the Service.
2. The Service
Stac provides managed infrastructure for running open-source AI models in production. This includes inference over the models made available in your plan, document retrieval, custom behavior configuration, API key management, and the dashboard used to administer all of it.
The specific capabilities available to you depend on the plan you subscribe to. We may add, improve, or modify features over time. If we discontinue a feature that is material to your plan, we will give you reasonable prior notice.
3. Accounts and eligibility
To use the Service you must create an account and provide accurate, complete registration information, keeping it up to date. You must be at least 18 years old and legally capable of entering into contracts.
You are responsible for all activity that occurs under your account and API keys, including activity by your employees, contractors, and end users. Keep your credentials confidential. API keys are secrets — treat them as such, do not embed them in client-side code or public repositories, and rotate them if you suspect exposure.
Notify us at stac@trystac.com as soon as you become aware of any unauthorized use of your account.
4. Plans, billing, and price changes
Fixed monthly pricing. Stac charges a fixed monthly fee per plan (Go, Pro, Max, and Enterprise). The fee is charged at the beginning of each billing cycle and does not vary with your volume of use within the capacity of your plan.
We do not charge per token. Your fee is not calculated per token, per request, or by any other consumption metric. Usage within your plan does not generate additional charges.
Payment processing. Charges for the Service are processed by Chargefy, a third-party payment provider engaged by Stac. Amounts are charged in Brazilian reais (BRL), and the accepted payment methods are Pix, bank slip (boleto bancário), and credit card.
By subscribing to a plan, you authorize Stac and Chargefy to process your subscription's recurring charges automatically, at the beginning of each billing cycle, for as long as the subscription remains active. For credit card payments, the charge is applied automatically to the registered payment method; for Pix or boleto payments, a new charge is issued each cycle, to be settled by its due date.
Your payment method data is collected and stored by Chargefy, not by Stac, as described in the Privacy Policy. Use of the payment method is also subject to Chargefy's own terms and privacy policy.
Trials. A free trial is available only on the Go and Pro plans, and only when the plan is contracted on the annual billing cycle. It is not available on the Max or Enterprise plans, nor on the monthly billing cycle.
The trial lasts 7 (seven) days from the date of sign-up. Registering a valid payment method is required to activate it. No charge is made during the trial period.
You may cancel at any time within those 7 days, free of charge — if you cancel before the deadline, no charge is ever made. If you do not cancel before the 7 days end, the full annual subscription amount is charged automatically at the end of the trial. After that charge, the ordinary cancellation and refund rules of these Terms apply — see the "Cancellation" paragraph above and Section 11.
Renewal. Subscriptions renew automatically for successive periods equal to the one purchased, unless cancelled before the end of the current cycle.
Cancellation. You may cancel at any time from your account settings. Cancellation takes effect at the end of the current billing cycle. You retain access until then, and the cycle in progress is not refunded on a pro-rata basis, except where refund is required by applicable law.
Refunds and cancellation. Refund rules vary according to the billing cycle you purchased:
- Monthly plan, first charge — after the first monthly plan charge, you have up to 7 (seven) days to request a refund and cancel the subscription. Once that period has passed, the charge already made is non-refundable;
- Monthly plan, subsequent charges — from the second billing cycle onwards, charges already made are not refunded. To avoid being charged for the next cycle, cancellation must be requested at least 7 (seven) days before the next billing date;
- Annual plan — the 7 (seven) day free trial is the only window in which you can cancel and avoid the annual charge. Once the annual charge has been made, there is no refund for the remaining period, except where required by applicable law.
Price changes. We may change plan prices with at least 30 days' prior notice. A price change applies only to billing cycles that begin after the notice period ends — it never applies to the cycle in progress. If you do not accept a new price, you may cancel before it takes effect.
Taxes. Prices are exclusive of taxes unless stated otherwise. You are responsible for any taxes applicable to your purchase, other than taxes on our income.
Payment failure and retries. If a recurring charge does not go through — for example, a card that is declined, expired, or over its limit, or a Pix or boleto charge left unpaid past its due date — Chargefy automatically retries the charge over a cure period, and we will notify you so that you can update your payment method or settle the outstanding charge. Your subscription remains active throughout that period, and no penalty applies if the charge succeeds on any of those attempts.
If the failure persists after the cure period ends, the following paragraph applies.
Non-payment. If a charge fails, we may suspend access to the Service after notifying you and allowing a reasonable period to cure. Persistent non-payment may result in termination under Section 11.
5. Building on the Stac API
This is expressly permitted and encouraged: you may build products and services on top of the Stac API and charge your own customers for them. This includes agencies, studios, and consultancies that deliver or resell solutions built on Stac to their own clients.
Doing so is not a violation of these Terms. It is the expected use of the Service. You retain your commercial relationship with your customers, and you set your own pricing for what you build.
Two conditions apply. First, you remain responsible to us for all use made through your account and keys, including use driven by your customers. Second, you may not simply hand over raw API credentials in place of an account — see Section 6.
6. Prohibited use
You may not:
- Circumvent, disable, or attempt to work around the capacity limits, quotas, or technical controls of your plan, including by distributing load across multiple accounts created to avoid a plan's limits;
- Resell, share, or transfer API keys directly to a third party as a substitute for that third party having their own account or being an end user of a product you have built;
- Use the Service for unlawful purposes, or to produce or distribute content that is illegal under applicable law;
- Use the Service to infringe intellectual property, privacy, or personality rights of others;
- Attempt to gain unauthorized access to the Service, other customers' data or environments, or the underlying infrastructure;
- Reverse engineer, decompile, or attempt to extract the weights, source code, or architecture of the Service or the models we operate, except to the extent this restriction is prohibited by law;
- Interfere with or disrupt the integrity or performance of the Service, including through deliberate overload, injection, or scraping at scale;
- Use the Service to develop a competing service by systematically copying its outputs or behavior.
We may investigate suspected violations and take the measures described in Section 11.
7. Your content and responsibility for AI output
Your content. You retain all rights to the data, prompts, documents, and files you submit to the Service ("Customer Content"). You grant us only the limited licence necessary to operate the Service for you — to process, transmit, and store Customer Content in order to return results to you. How we handle Customer Content, including our commitment not to train models on it, is described in our Privacy Policy.
You are responsible for having the rights and legal basis necessary to submit Customer Content to the Service.
AI output. Generative AI is a developing technology. Model output may be inaccurate, incomplete, outdated, offensive, or otherwise unsuitable for your purpose, and identical inputs may produce different outputs. We do not guarantee the accuracy, reliability, or fitness of any output.
You are responsible for reviewing and validating output before relying on it, publishing it, or presenting it to your own customers. Do not use the Service as the sole basis for decisions requiring professional judgment — including medical, legal, financial, or safety-critical decisions — without qualified human review.
8. Availability
The Service is provided "as is" and "as available". We work to keep it operating reliably, but we do not warrant that access will be uninterrupted or error-free. Maintenance, updates, failures in third-party infrastructure, and events outside our reasonable control may affect availability.
No specific availability or performance commitment forms part of these Terms. Where a formal service level agreement applies, it is set out in a separate Enterprise contract signed between you and Stac, and only the terms of that contract govern it.
9. Intellectual property
The Service, including the platform, dashboard, documentation, trade marks, and all software and infrastructure behind it, belongs to Stac or its licensors. These Terms grant you a limited, non-exclusive, non-transferable, revocable right to use the Service in accordance with your plan. No other rights are granted by implication.
The open-source models made available through the Service remain subject to their own licences. Where a model licence imposes conditions on use or distribution of output, those conditions apply to you as well.
Feedback you send us about the Service may be used to improve it, without obligation or compensation to you. Feedback is not Customer Content and should not include confidential information.
10. Confidentiality
Each party may receive non-public information from the other in connection with the Service. The receiving party will use it only for the purposes of these Terms and protect it with at least the care it applies to its own confidential information. This does not apply to information that is public, independently developed, lawfully received from a third party, or required to be disclosed by law or valid order — in which case the disclosing party will be notified where legally permitted.
11. Suspension and termination
You may terminate at any time by cancelling your subscription and closing your account.
We may suspend or limit access, in whole or in part, where necessary to protect the Service, our customers, or third parties — including in cases of suspected violation of Section 6, security risk, or non-payment. Where circumstances allow, we will notify you first and give you an opportunity to remedy the issue. In cases of serious or repeated violation, or where required by law, we may terminate immediately.
We may also terminate for convenience with at least 30 days' prior notice, refunding any amount already paid for a period not yet provided.
On termination, your right to use the Service ceases and API keys stop working. Treatment of Customer Content after termination, including retention windows, is described in our Privacy Policy.
12. Limitation of liability
To the maximum extent permitted by applicable law:
Cap. Stac's total aggregate liability arising out of or relating to these Terms or the Service — regardless of the legal basis of the claim — is limited to the amount paid by the customer in the last monthly billing cycle preceding the event that gave rise to the liability.
Excluded damages. We are not liable for lost profits, lost revenue, loss of business opportunity, loss of data, or indirect, incidental, special, punitive, or consequential damages, even if advised of their possibility.
Output and reliance. Without limiting Section 7, we are not liable for consequences arising from your use of, or reliance on, AI output that you did not validate.
Mandatory rights are preserved. Nothing in these Terms excludes or limits liability that cannot be excluded or limited under applicable law — including rights guaranteed to consumers under the Brazilian Consumer Protection Code (Law 8.078/1990), and liability for fraud or wilful misconduct. If you use the Service as a consumer, the protections of that Code apply to you in full, and this Section applies only to the extent it does not conflict with them.
13. Indemnification
You will indemnify and hold Stac harmless against third-party claims, losses, and reasonable expenses arising from your Customer Content, from your products and services built on the Service, or from your breach of these Terms or of applicable law — except to the extent the claim results from our own breach.
14. Changes to these Terms
We may update these Terms. Where a change is material, we will give at least 30 days' prior notice by email or through the Service before it takes effect. Continuing to use the Service after a change takes effect means you accept the updated Terms. If you do not accept them, you may cancel before they take effect. The "last updated" date at the top of this page always reflects the current version.
15. Governing law and venue
These Terms are governed by the laws of the Federative Republic of Brazil. The courts of the judicial district of Curitiba - PR are competent to resolve disputes arising from them, except where mandatory law — including consumer protection law — establishes a different venue in your favour.
16. Miscellaneous
If any provision of these Terms is held invalid or unenforceable, the remainder stays in force. Our failure to enforce a provision is not a waiver of it. You may not assign these Terms without our prior written consent; we may assign them in connection with a merger, acquisition, or sale of assets, with notice to you. These Terms, together with any Enterprise contract signed between us, form the entire agreement on their subject matter.
17. Contact
Questions about these Terms:
stac@trystac.com