Terms of Use

CS with ZAK (“the Site”, “we”, “us”) is operated by Zafar Ali Khan (“ZAK”), an individual educator based in Karachi, Sindh, Pakistan, trading as CS with ZAK. You can reach us at contact@cswithzak.com or on WhatsApp at +92-3-111-222-ZAK.

These Terms of Use (“Terms”) govern your use of cswithzak.com and everything served from it — the Learn pages, AskZ Smart Notes, ZAK Assignments, the video library, the past-paper finder and question bank, the pseudocode, Python, SQL, assembler and Prolog labs and the other tools, quizzes, flashcards, infographics, the glossary and command-words pages, the blog, the Help Centre, the My Progress dashboard, the AskZ chat drawer and the /askz page — together with the ZAPP apps for Android, iPhone and iPad (“the Services”). Separate documents that form part of these Terms by reference:

• the Privacy Policy and Cookies & Local Storage notice;
• the AskZ & AI Transparency notice;
• the Acceptable Use Policy;
• the Copyright, Trademarks & Takedown notice;
• the Educational Disclaimer;
• the Tuition, Success Packs & Merchandise Terms, if you buy or enrol in anything;
• the Testimonials & User Content policy, if you submit anything to us.

By using the Services you agree to these Terms. If you do not agree, please do not use the Services.

The Services are designed for Cambridge O Level, IGCSE, AS and A Level Computer Science students, who are typically between 13 and 19 years old, and for their teachers and parents.

• If you are under 18, you may use the free Services, but you confirm that a parent or guardian is aware you are using them and is happy for you to do so. Enrolment in classes, Success Packs or any paid service must be arranged by a parent or guardian (see the Tuition Terms).
• We do not knowingly collect personal information from children under 13, and the Services are not directed at them. If you are under 13, do not send us your name, phone number, email or any other personal information, and do not type personal information into AskZ. If we learn that we hold personal information from a child under 13 without a parent's consent, we will delete it — see the Privacy Policy.
• Parents and guardians: you are welcome to use the site alongside your child, and to contact us with any concern at contact@cswithzak.com. Our Child Safety & Safeguarding policy explains how we look after students.

We own, or hold a licence to, the material we create for the Site: the notes and topic pages, the Smart Notes and Assignments that AskZ writes from ZAK's material, the wording of quizzes, flashcards, model questions, code examples, infographics, the glossary, the blog posts, the pseudocode interpreter, the Python, SQL, assembler and Prolog labs and the other tools, the video library's topic index, the look and feel of the Site, and the “CS with ZAK”, “AskZ”, “ZAPP” and “ZAKATHON” names and logos (“ZAK Content”).

Subject to these Terms, we grant you a free, personal, non-exclusive, non-transferable, revocable licence to:

• read, watch, run and use ZAK Content for your own study or teaching;
• download or print reasonable copies of notes, Smart Notes, assignments and infographics (including the PDF and slide exports) for your own revision, or for use with the students you teach, provided each copy keeps the “CS with ZAK · cswithzak.com” attribution and is not sold or bundled into a paid product;
• share links to any page freely — that is what the site is for.

You may not, without our written permission:

• copy, republish, redistribute, mirror or make available ZAK Content on another website, app, channel, drive, group or paid course, in whole or in substantial part;
• remove attributions, watermarks or the ZAK branding, or present ZAK Content as your own or anyone else's;
• sell, rent, sublicense or commercially exploit ZAK Content, including by bundling it into “notes packs” sold to students;
• use ZAK Content, the exam bank, the interpreter or AskZ's answers to train, fine-tune or evaluate a machine-learning model, or scrape, crawl or bulk-download the Site (an exception for search engines and archival crawlers that respect our robots.txt is described in the Acceptable Use Policy);
• decompile, reverse-engineer or copy the source code of the Site or ZAPP except to the extent a law says we cannot stop you.

Material belonging to other people (Cambridge past-paper questions and mark schemes, syllabus PDFs, textbook references, YouTube videos, the Blogger posts, third-party logos) is not licensed to you under this section. It stays under its owner's terms; see Copyright, Trademarks & Takedown.

Teachers at schools: you may use ZAK Content in your own lessons and hand-outs with attribution. If you would like to build a whole course or a school-wide deployment around it, talk to us — we usually say yes.

Without an account (the default, on the website and in ZAPP), the My Progress dashboard, weak-card memory, planner, the code you type in the playground and labs, and the Smart Notes and assignments you have opened (with your answers, self-marks and mastery ticks) save their state on your own device — your browser's local storage and IndexedDB, or the app's private storage on your phone — and never send it to us. That means:

• your progress is tied to that browser or phone — clear site data, uninstall the app, use a different browser, or use private/incognito mode and it will not be there;
• anyone who uses that same browser profile or phone can see it;
• we cannot recover, transfer or delete it for you (you can: your browser's “clear site data” or the app's Reset progress does it, and each tool has its own reset). The Dashboard on the website and in ZAPP can also export your progress as an encrypted backup file, which only imports again unchanged — an edited file is refused, and an older unencrypted export brings back your topics, quizzes and bookmarks but not its XP.

The name you type on the dashboard is only used to greet you on that device.

The optional account. You can sign in on /account or in ZAPP's Settings to keep one copy of your progress on our server and see the same progress on every device you sign in on. By creating one you agree that:

• Sign-in is by email only. You enter an email address you control; we email a six-digit code (valid for 10 minutes) and there is no password. Use your own address — one account per person — and do not sign in on a device other people use unless you sign out afterwards. One mailbox is one account: variants of an address that deliver to the same inbox (a +tag, or dots and googlemail.com in a Gmail address) sign in to the same account.
• Parents. You may invite a parent or guardian to see a read-only summary of your progress (Privacy Policy §3l); invite only your own parent or guardian, and remove them whenever you like. A parent who accepts uses their own account and must not share the view with anyone else.
• What is stored is listed in the Privacy Policy §3l (and §9 for the app): your email address, your progress document, what you have written on past-paper questions in the website's paper workspace and, for each signed-in browser or phone, a hashed sign-in token with the browser or app type and the date. If you post in the Discussion Corners, your nickname, posts and safety records are kept too (§3n). If you redeem an ebook code, your licence, reading devices and the notes you make in the book are kept too (§3o); the ebook licence itself is in the Tuition, Success Packs & Merchandise Terms §5a.
• Teacher access. The Paper Builder is for teachers. You may request it only for yourself, with your own school or institution email, and the details you give must be true; access is ZAK's decision, may be refused or paused at any time, and is for setting papers for your own classes. A student may sit a paper a teacher shares but not build one. A class link you make collects the results of signed-in students who choose to send them (a name they choose and their marks, never their answers): use them only to teach that class, keep any CSV you export secure, and tell your students — and, where your school requires it, their parents — that their name and marks come to you. A student sends a result only by pressing Send my result to my teacher, and may withdraw it. A class list you keep is yours to use only for that class: add only students you teach, with addresses you are allowed to use (for a Google Classroom import, your school's rules for Classroom data apply), and remember each student decides whether to join. When you change a built paper you are asked why; your reasons and note are kept as feedback for ZAK and are read by AskZ to decide which questions to replace and how (Privacy Policy §3l). A strict exam you set keeps your students' answers, marks and flags on the AskZ server: tell your students (and, where your school requires it, their parents) what it records before they sit it — the room's door lists it for them too. It is a controlled room, not proctoring: it cannot see a second device or a person in the room, and its flags (time away from the tab, leaving full screen, paste or print attempts, a second device) are information for your judgement, never proof of cheating. AskZ's marks are estimates against the official scheme; you check them and release the final marks, and the results are yours to use only to teach that class.
• School licence. A school may take a licence for its Computer Science department (/schools). It is agreed with ZAK by message and paid by invoice (bank transfer or Raast in Pakistan, Payoneer abroad) — nothing is sold on the site and no card details are taken here. A licence adds, for the approved teachers ZAK links to the school: a monthly AI allowance for AskZ-written Paper Builder questions and paper changes (when it is used up, the free teacher tier applies until the next month), and a view of the class links colleagues at the same school have set (title, paper, mark total and the number of results — never a student's name, answers or marks). It never changes what students can use, nothing free is moved behind it, and when it ends every teacher keeps the free tier with their papers, links and results as they were. A pilot term may be free. The school is responsible for telling ZAK when a teacher leaves; ZAK may pause a licence that is misused under the Acceptable Use Policy.
• Sign-ins last 180 days on each device, then you sign in again. Sign out ends that device only.
• How devices are combined. Your best attempt at each exam question is kept (when the same answer is marked again — a recheck, a challenge or your own change — the newest mark replaces it), quiz results from every device are combined, and lists such as bookmarks and completed topics follow the device that changed them most recently (on the website, the first time a browser joins an account its lists are combined with the account's instead). A change made offline is sent the next time that device is online, so a later change on another device can overwrite it.
• How XP is worked out. XP is not a number your device sends: our server works it out from what you did — topics you marked completed (once per topic), quiz rounds, past-paper and task questions together with who gave each mark (more XP for a mark given by the site's own marker or by AskZ than for one you gave yourself), and counts of flashcards, programs run, practice answers and game XP. An account can earn at most 600 XP a day, with smaller limits for each kind of activity, and progress made on a device before you signed in is brought along once, up to 2,000 XP. Your streak is the number of days in a row your account saved progress. AskZ's marks count only as AskZ actually gave them: when you are signed in and ask AskZ to mark a question, our server keeps the marks it gave each part with a short fingerprint of the answer it marked (not the answer itself) for 400 days, or until you delete your account. Anything sent that cannot be counted (for example AskZ marks it has no record of, or a question that is not in our bank) is left out and recorded for 90 days (account id, display name, what was left out) so ZAK can see it in his admin tools and set a total by hand if that was wrong. Nothing else changes — you stay signed in and nothing is restricted. Past-paper work is kept per question: the copy saved most recently wins, and clearing a question clears it on your other devices too.
• Past-paper work has limits. It covers past-paper questions and the AskZ-written, model and assignment questions you answer on a typeset paper; a question inside a built paper or a timed sitting has its own copy. Each question's copy is capped at 256 KB (very heavy ink is sent with fewer points per stroke; your own device keeps every point), and the account keeps up to 5 MB and 2,000 questions — past that, the questions you changed longest ago are dropped from the account copy first (never from your device), and /account tells you which are not synced.
• Deleting your account (Delete my account on /account or in the app's Settings) erases your email, the progress document, your synced past-paper work and every device's token from our server immediately and permanently, and deletes your Discussion Corners posts, nickname, reactions, votes, blocks and memberships. What is already on each device stays there until you reset it.
• It is a convenience copy. The account is free, has no service-level guarantee, and may be unavailable while the server is down; export anything you cannot afford to lose. We may suspend or delete an account used to break the Acceptable Use Policy or these Terms.
• Age. You must be 13 or over to create an account, and if the law where you live sets a higher age for agreeing to online services yourself, a parent or guardian must agree first (Privacy Policy §8).

AskZ is an artificial-intelligence tutor, not a person. Every AskZ answer is generated by a large language model and may be incomplete, out of date or simply wrong, even when it sounds confident. The mark scheme, the syllabus and your teacher take precedence over AskZ. AskZ is free within a daily allowance: 10 chat messages a day on each internet connection without an account, 25 a day with a free account — raised to 20 and 60 during Cambridge exam seasons (from the start of the month before a series' first Computer Science paper to its last one); and when AskZ's free budget for the day is used up, it rests until the next day while every other tool keeps working. Photos and files you add to a chat, and AskZ's marking of your answers, have their own daily limits (documents need a free account, and a guest adding a photo may first be checked automatically for being a person, not a bot). We may change these numbers as costs and demand change; the current ones are always shown when you reach them. The AskZ & AI Transparency notice explains what AskZ is, what it is not, what it does with your messages and its limits; it forms part of these Terms.

Smart Notes and ZAK Assignments are also written by AI — once per topic, from ZAK's own material, the syllabus and past papers — and then shared with every student who opens that topic. They are labelled as AskZ-written and are not checked line by line by a person before they appear; treat them exactly like an AskZ answer and check anything surprising against the syllabus and mark scheme.

The pseudocode, Python, Java and VB.NET playgrounds, the SQL, assembler and Prolog labs, the trace-table generator, the logic-gates, Boolean-algebra and number-systems labs, Flowchart Studio, the translator, the auto-marked programming tasks, the Paper Builder (for teachers) and the other labs run locally in your browser, or on your phone in ZAPP (the Python runtime is downloaded from a content-delivery network the first time you run Python, and the Java and VB.NET compilers from this site the first time you use them; the code you write never leaves the page or the phone). They are provided to help you practise; they are not an official Cambridge marking tool and their output is not a guarantee of marks.

The Site links to and loads content from other people: Cambridge International Education's own site, PapaCambridge and BestExamHelp (past-paper PDFs), YouTube (the video library plays ZAK's lectures through YouTube's privacy-enhanced player), jsDelivr (the CDN that serves the Python runtime), Facebook, WhatsApp, Discord, Blogger, Google Drive/OneDrive, GitHub, the Apple App Store and Google Play, and others. Those sites have their own terms and privacy policies and we do not control them. A link is not an endorsement, and we are not responsible for their content, availability or what they do with your data. Past-paper PDFs in particular are hosted by third parties and may move or disappear.

You agree to use the Services only for lawful purposes and in line with our Acceptable Use Policy, which is part of these Terms. In short: no abuse of people or of AskZ, no attacks on the Site, no scraping, no cheating-as-a-service, no impersonation, no uploading of other people's personal information.

If you submit a testimonial, send us a correction, suggest a question, report a bug, or otherwise send us material, the Testimonials & User Content policy applies. You keep ownership; you give us a licence to use it as described there; you promise it is yours to give and does not break anyone's rights or the law.

Ideas and suggestions: we love them, but we cannot promise to keep them confidential or to pay for them, and we may already be working on something similar.

The Services are provided free of charge, largely by one teacher, on a best-efforts basis. We may change, suspend or withdraw any part of the Services at any time — for maintenance, because a third party changed something, because the syllabus changed, or for any other reason — without notice or liability. We try to keep the site up, fast and correct, but we do not promise that it will be uninterrupted, error-free or available in every country.

We may block or restrict access (for example by IP address or device) for anyone who breaks these Terms or the Acceptable Use Policy, and we may report unlawful behaviour to the appropriate authorities.

To the fullest extent permitted by law, the Services and all content are provided “as is” and “as available”, without warranties of any kind, express or implied — including any warranty of accuracy, completeness, fitness for a particular purpose, non-infringement or that your grades will improve. In particular:

• ZAK Content is an interpretation of the Cambridge syllabuses for teaching purposes. The official syllabus, specimen papers, mark schemes and examiner reports published by Cambridge International Education are the authority; where we differ, they win.
• Exam dates, Key Times, zones and timetables shown in the Exam Planner are transcribed from Cambridge's published timetables for your convenience. Your school or exam centre's statement of entry is the only authoritative source of your exam dates and times. Confirm with them.
• Past-paper availability, syllabus changes and grade thresholds are Cambridge's to determine; we reflect them as best we can.

The Educational Disclaimer has the full list.

11.1 What this section covers. “Exam Statistics” means every figure, label, ranking and estimate the Services derive from past examination papers, including the Statometer (how often a topic, syllabus bullet or assessment objective has been set, the estimated chance of it appearing, expected marks, importance tiers such as “Banker” or “Core”, and “revision priority”), the topic, sub-topic and assessment-objective tags on the past-paper question bank, the question maps and command-word usage on the past-paper and command-word pages, the default topic weights of the Paper Builder, and the revision order in the Exam Planner, wherever they appear (website, ZAPP, AskZ answers, downloads or posts).

11.2 Produced automatically; may be wrong. Exam Statistics are produced by software that files questions and mark-scheme points under topics and objectives by rules and classifiers. Filing can be wrong, papers can be missing or misread, and our tags are our own estimates — examination boards do not publish them. We correct errors when we find them, but we do not warrant that any Exam Statistic is accurate, complete or current.

11.3 About the past, not the future. Exam Statistics describe papers that have already been set. They are not a forecast, prediction or disclosure of the content of any future paper. Examination boards may set any part of the syllabus in any session, change the pattern of their papers at any time, and are not bound by anything a statistic shows. We have no access to unreleased examination material.

11.4 No guarantee of results. Nothing in or derived from Exam Statistics is a promise, representation or guarantee of any mark, grade, result, ranking, place, scholarship or admission.

11.5 Not advice. Exam Statistics are general information. They are not academic, educational, careers or professional advice tailored to you, and they do not replace the official syllabus, your teacher or your school. Do not leave any part of the syllabus unrevised because of them.

11.6 Official documents prevail. If an Exam Statistic, or anything AskZ says about one, differs from a syllabus, specimen paper, question paper, mark scheme, examiner report or notice issued by the examination board, the board's document prevails.

11.7 Reliance. You decide how to use Exam Statistics and do so at your own risk. To the fullest extent permitted by law, neither Zafar Ali Khan (“ZAK”), an individual educator based in Karachi, Sindh, Pakistan, trading as CS with ZAK, nor AskZ, nor anyone who helps provide the Services is liable for any loss or damage — including disappointing results, lost opportunities, or time or money spent — arising from reliance on Exam Statistics. Section 12 applies to this section, and nothing here limits liability that cannot lawfully be limited or affects your statutory rights as a consumer.

11.8 Refunds. Exam Statistics are provided free with every part of the Services. A difference between an Exam Statistic and the content of an actual examination, or any result you obtain, is not by itself a ground for a refund, credit or compensation under these Terms or the Tuition, Success Packs & Merchandise Terms. Any refund rights you have under those terms or under law are unaffected.

Nothing in these Terms excludes or limits liability that cannot be excluded by law — including for death or personal injury caused by negligence, for fraud, or for any statutory consumer rights you have that cannot be waived.

Subject to that, to the fullest extent permitted by law:

• we are not liable for any loss or damage arising from your use of, or inability to use, the free Services or any content on them — including lost marks, lost exam entries, missed exams, lost data in your browser, or decisions you make based on ZAK Content or AskZ;
• we are not liable for any indirect, incidental, special, consequential or punitive loss, or for loss of profit, data, goodwill or opportunity, however arising;
• our total aggregate liability to you in connection with the free Services will not exceed PKR 10,000 (or, if you have paid us for a service, the amount you paid for that service in the twelve months before the claim, as set out in the Tuition Terms).

You agree to indemnify us against claims, losses and costs arising from your breach of these Terms or your misuse of the Services.

These Terms, and any dispute or claim arising out of them or your use of the Services, are governed by the laws of the Islamic Republic of Pakistan. The courts of Karachi, Sindh have exclusive jurisdiction, except that we may seek an injunction or protection of our intellectual property in any court that has jurisdiction.

If you live in a country whose consumer-protection or data-protection laws give you rights that cannot be overridden by a choice of law (for example the EU/EEA, the United Kingdom, or certain US states), you keep those rights.

Before starting any formal proceedings, please email legal@cswithzak.com with “Dispute” in the subject line. We will acknowledge within 7 days and try in good faith to resolve the matter within 30 days.

• Entire agreement. These Terms and the documents they reference are the whole agreement between you and us about the Services.
• Changes. We may update these Terms from time to time. The date at the top tells you when they last changed; material changes will be flagged on the /legal hub for at least 30 days. Continuing to use the Services after a change means you accept it.
• Severability. If any part of these Terms is found unenforceable, the rest stays in force.
• No waiver. If we do not act on a breach straight away, we can still act on it later.
• Assignment. You cannot transfer your rights under these Terms. We may transfer ours to a successor who runs the Site, and we will tell you here if we do.
• Language. These Terms are written in English; any translation is for convenience and the English version prevails.
• Contact. contact@cswithzak.com · WhatsApp +92-3-111-222-ZAK · Contact page.