Terms of Service
Policy version: 2026-09-28 · Effective date: September 28, 2026
These Terms of Service (“Terms”) govern your use of Langu, a real-time language learning chat application operated by Alexandre Marques Kaio (“Langu”, “we”, “our”, or “us”). Before you create an account or create or upload user-generated content, the app requires you to explicitly accept the current version of these Terms. Acceptance is not inferred from opening a link, requesting a sign-in code, or continuing to use the app. The Privacy Policy is provided separately and explains how we process personal data. If you do not accept these Terms, do not create an account or use Langu's content-sharing features.
1. Eligibility
You must be at least 13 years old to use Langu. Before account creation, you must separately attest that you are at least 13. If you are 13 through 17, a parent or legal guardian must review and agree to these Terms and the Privacy Policy on your behalf. Institutional accounts (Schools, Schools+) established on behalf of minor users are governed by Section 10.
2. Your account
Langu uses phone number verification (OTP) as the sole method of account creation. You are responsible for keeping your phone number and any session tokens secure. You may not create more than one personal account or share your account with others.
You can update your display name, profile picture, and about text at any time in Settings. You can delete your account at any time in the app via Settings → Delete Account, confirmed with a one-time code sent to your phone. After acceptance, access is removed promptly and deletion continues in the background within a single 30-day maximum. Langu sends one completion SMS when the tracked erasure finishes. If you no longer have access to the app, follow the instructions at languchat.com/delete-account or email support@languchat.com with the subject “Delete my account” and we will process the request within 30 days. Account deletion is permanent and cannot be undone.
3. Subscription plans and pricing
Langu offers three consumer tiers and institutional plans. All prices are listed inclusive of applicable taxes unless stated otherwise.
3.1 Consumer tiers
| Tier | Brazil (monthly) | Brazil (annual) | USA (monthly) | USA (annual) |
|---|---|---|---|---|
| Free | R$0 | — | $0 | — |
| Plus | R$24,90 | R$179/yr | $7.99 | $59/yr |
| Pro | R$44,90 | R$329/yr | $14.99 | $109/yr |
3.2 7-day Plus free trial
Every new account automatically receives a 7-day Plus trial — no payment method required. At the end of the trial, your account reverts to the Free tier unless you purchase a subscription. The trial is available once per identity (phone number + device). Creating multiple accounts to claim additional trials violates these Terms and may result in account suspension.
3.3 Boost packs (one-time purchases)
Boost packs are consumable add-ons that grant a fixed quota of grammar explanations or conversation suggestions with a 90-day expiry from the date of purchase. Unused quota expires at the end of the 90-day window. Boost packs are available for purchase inside the app (via Apple App Store or Google Play) and on our website (via Pix or card).
| Pack | Brazil | USA | Contents |
|---|---|---|---|
| Grammar Boost | R$9,90 | $2.99 | +100 grammar explanations (90-day expiry) |
| Suggestions Boost | R$9,90 | $2.99 | +50 conversation suggestions (90-day expiry) |
| Combo Boost | R$14,90 | $4.49 | +100 grammar + 50 suggestions (90-day expiry) |
3.4 Institutional plans (Schools and Schools+)
Institutional plans are available for language schools, educational institutions, and enterprises. These plans are governed by a separate agreement between Langu and the institution. Individual users invited under an institutional plan are subject to both these Terms and the institutional agreement. Minimum seat count and pricing are available at support@languchat.com.
3.5 Price changes
We may change subscription prices at any time. For existing subscribers, price changes take effect at the next billing cycle after at least 30 days' notice via email or in-app notification. You may cancel before the changed price takes effect; keeping the subscription active authorizes the next renewal at that price.
4. Billing and payment
4.1 Payment methods
Subscriptions purchased through the Apple App Store or Google Play are billed by Apple or Google respectively under their own payment terms. RevenueCat validates those store purchases and manages subscription entitlements using an account-linked customer identifier and purchase history. Subscriptions and boost packs purchased on our website are processed by Stripe. In Brazil, web purchases may be paid via Pix or credit/debit card.
4.2 Automatic renewal
Monthly and annual subscriptions renew automatically at the end of each billing period unless you cancel before the renewal date. For in-app purchases, cancellation is managed through your Apple or Google account settings. For web purchases, cancellation can be requested by emailing support@languchat.com. Cancellation stops future charges but does not terminate your access until the end of the current billing period.
4.3 Annual plan — subscription commitment
Annual plans are billed as a single upfront charge covering 12 months. If you cancel an annual plan after the 7-day refund window (see Section 5), your access continues until the end of the 12-month period — no partial refunds are issued for unused months.
5. Refunds
5.1 Web purchases — 7-day refund right (Brazil)
In accordance with Article 49 of the Brazilian Consumer Defense Code (CDC), you have the right to cancel any subscription or boost pack purchased on our website within 7 calendar days of the purchase date and receive a full refund, with no questions asked. To exercise this right, email support@languchat.com with subject “Refund request” within the 7-day window. Refunds are processed within 10 business days to the original payment method.
5.2 After the 7-day window
After the 7-day window, subscriptions and boost packs purchased on our website are non-refundable except where required by applicable law. Automatic renewal charges are non-refundable once the new billing period has started.
5.3 In-app purchases (Apple / Google)
For purchases made through the Apple App Store or Google Play, refunds are handled entirely by Apple or Google under their respective refund policies. We have no ability to issue refunds for in-app purchases — please contact Apple or Google support directly.
6. Fair use and feature limits
Features marked “unlimited” or “fair use” are subject to reasonable use limits to ensure service quality for all users. Current fair-use caps are: Plus — 1,000 translations/day, 30 grammar explanations/day, 10 conversation suggestions/day; Pro — 2,000 translations/day, 200 grammar explanations/day, 50 conversation suggestions/day. We reserve the right to adjust these limits with notice. Automated or programmatic use of Langu features beyond what a human user would generate is prohibited.
7. Acceptable use
You agree not to use Langu to:
- Send spam, scams, unsolicited commercial messages, or mass automated messages.
- Harass, bully, threaten, intimidate, or abuse another person.
- Promote hate or discrimination based on a protected characteristic.
- Create, share, request, or solicit sexual or exploitative content, including child sexual abuse material (CSAM), grooming, sextortion, or trafficking.
- Impersonate another person or organisation, facilitate illegal activity, or violate another person's privacy or intellectual-property rights.
- Attempt to access another user's account or data without authorization.
- Reverse-engineer, decompile, or tamper with the app or its APIs.
- Use the service in a way that impairs its performance for other users.
- Evade enforcement or circumvent blocks, suspensions, feature limits, quotas, or subscription controls (for example, trial farming).
- Use the Telegram or WhatsApp bridge features in violation of Telegram's or Meta's Terms of Service.
We reserve the right to suspend or terminate accounts that violate these rules, with or without prior notice, at our sole discretion.
7.1 Safety tools: blocking and reporting
Langu provides separate, clearly labelled in-app safety tools. You can block a user to stop further direct interaction, and you can report a user or content for human review. Applicable AI features also provide a way to report offensive AI-generated output without leaving the app. Reports may be classified as harassment, spam, inappropriate content, other, or child safety. If the in-app path is unavailable, contact support@languchat.com to report a safety concern.
Accepted reports enter a human-operated queue. Depending on the facts, an operator may find no violation, make referenced content unavailable, suspend an account, record a manual child-safety escalation, or review an AI-safety concern. Langu's operational target is to begin child-safety review and escalation within a one-hour window and to resolve standard reports within a 24-hour window. These are response targets, not promises of a particular deadline or outcome for an individual report.
7.2 Child safety standards
Langu prohibits child sexual abuse and exploitation (CSAE), child sexual abuse material (CSAM), grooming, sextortion, trafficking, solicitation, and any other content or behavior that sexually exploits, abuses, or endangers children. Use the in-app report feature or contact our monitored child-safety address at support@languchat.com.
A trained human reviews child-safety reports and, with current legal guidance, decides whether to preserve bounded evidence, restrict access, suspend an account, or report confirmed CSAM to NCMEC or the applicable regional authority when legally required. The software does not make an automated legal conclusion or automatically contact an authority.
7.3 Report context and moderation records
A human-content report contains the selected reason, optional note, and the specific user or message identified by the reporter. An AI-output report contains the selected reason, the reported output (limited to 4,000 characters), its feature, and limited technical identifiers or model details when available. Langu does not copy unrelated conversation history into the report. See the Privacy Policy for retention, account deletion, and legal-hold details.
8. Your content
You retain ownership of the messages and content you send through Langu. By using the service you grant Langu a limited, non-exclusive, worldwide licence to store, transmit, and process your content solely as necessary to operate the service — including forwarding messages to recipients, running translation and AI features, and storing messages on our servers while their chat exists, subject to message and account deletion rules described in our Privacy Policy.
A sender may delete a message for everyone during the app's available deletion window. Account deletion erases the account holder's authored text, translations, captions, transcripts, uploaded media references, and other Langu-managed derivatives for all participants. Those messages become the normal deleted-message placeholder; other participants keep their own messages and the conversation shell. Langu cannot remove screenshots, downloads, exports, or other independent copies outside its control.
We do not use your private messages for advertising, training AI models on a personally identifiable basis, or any purpose beyond operating and improving the service. Message content sent to Google Translate and OpenAI for translation and AI features is governed by those providers' terms; see our Privacy Policy for details.
9. Third-party services and bridges
Langu integrates with third-party services including Google Cloud Translation, OpenAI, Expo push notifications, Expo Observe, Sentry, RevenueCat, Stripe, the Telegram API (Pro tier), and the WhatsApp Cloud API (Pro tier, coming soon). Your use of these integrations is also subject to the respective providers' terms of service. Langu is not responsible for changes to or discontinuation of third-party services, including any interruption to cross-channel bridges caused by policy changes by Telegram or Meta.
10. Institutional accounts
Schools and institutions that purchase a Schools or Schools+ plan accept these Terms on behalf of their organisation and warrant that they have obtained all necessary consents to enrol their users — including parental or guardian consent for users under 18, as required by the Brazilian Lei Geral de Proteção de Dados (LGPD) and applicable law. The institution is the data controller for its users' data under the institutional plan; Langu acts as the data processor.
11. Service availability and modifications
We aim for high availability but do not guarantee uninterrupted service. We may modify, suspend, or discontinue features at any time. For material changes that reduce the features included in a paid plan, we will give at least 30 days' notice and offer a pro-rated refund for any prepaid period affected. For changes to Free tier features, no refund applies.
12. Disclaimers and limitation of liability
Langu is provided “as is” without warranties of any kind, express or implied. We do not warrant that translations, grammar explanations, or AI suggestions are accurate, complete, or fit for any particular purpose — they are provided as learning aids only and should not be relied upon for legal, medical, or professional purposes.
To the fullest extent permitted by applicable law, Langu's total liability to you for any claim arising from these Terms or your use of the service is limited to the amount you paid to Langu in the 3 months preceding the claim. We are not liable for indirect, incidental, consequential, or punitive damages.
Nothing in these Terms limits liability that cannot be excluded under mandatory consumer protection law, including the Brazilian CDC.
13. Governing law and disputes
These Terms are governed by the laws of Brazil. For consumer users, mandatory consumer protection rules of your country of residence also apply. Any disputes that cannot be resolved informally should be submitted to the courts of São Paulo, Brazil, except where mandatory local law provides otherwise.
Before initiating formal proceedings, please contact us at support@languchat.com — most issues can be resolved quickly.
14. Changes to these Terms
We may update these Terms from time to time. For material changes, we will notify you at least 30 days in advance via email or in-app notification. The updated Terms will be posted at languchat.com/terms with a new policy version and effective date. When a new version requires acceptance, the app will ask you to explicitly accept it before you can create or upload user-generated content. If you do not agree, you may cancel your subscription, sign out, or delete your account.