The Complete Guide to BCS Preparation With Claude Code

BCS preparation with AI, built as a system: a Claude Code folder of your books and past papers, where every question is checked against its page first.

Shamim Hossain6 November 2026

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For the 47th BCS, the PSC advertised 3,688 posts.^[1] 374,747 people applied.^[2] The circular came out on 28 November 2024, and the final result on 28 June 2026.^[5] That’s 19 months of studying, waiting and studying again.

AI can’t make the PSC move faster. It can give you back the hours that go into rereading, hunting for notes and guessing what to study next, but only if you stop using it as a chat box. Most writing on BCS preparation with AI is either a syllabus-and-books list with no AI in it, or an advert for an app. None of it shows you how to build a setup where the AI works only from your own books and past papers, and where every question it writes is checked against a page before you study it. That’s what this post does, using Claude Code, with a cheaper path on the free plan.

What you’re up against, in numbers

The preliminary is a 200-mark MCQ test.^[7] Each right answer earns 1 mark and each wrong one costs half a mark, so a guess is a gamble, not a free shot. For the 50th BCS, 290,951 people applied^[2] and 6,165 passed the written test.^[10] After the written comes the viva, now worth 100 marks, down from 200.^[8] The government has said 100 marks will stay for the 50th BCS and after.^[9]

Time is the other wall. The 41st BCS took four years and four months from start to finish.^[12] In December 2024 the maximum age went up from 30 to 32,^[4] and the 50th BCS circular asked for applicants aged 21 to 32 on 1 November 2025.^[3] Two extra years help. They also mean more of your twenties can go into one exam. Whatever saves you hours is worth setting up well.

Why a chat box isn’t enough

A mistake we see often: candidates trust the chatbot’s answer and copy it straight into their notes. A wrong date or a wrong article number looks exactly as confident as a right one. In Bangla it’s harder still to judge: a 2026 research paper that built a benchmark for Bengali found that, before it, nobody had systematically measured how often large language models make things up in Bengali.^[16] So no one can tell you how often a chatbot gets Bangladesh affairs wrong. Assume it does, sometimes, and build your method around that.

A chat box makes that hard. Each conversation starts from nothing, the AI answers from whatever it absorbed in training, and your rules (“only from my book”, “show the page”) have to be typed again every time. Claude Code works on a folder on your computer instead. It reads the files in that folder, follows a rules file you write once, and can hand work to a second checker. In the Claude desktop app it’s the Code tab,^[22] and you can work in it without opening a terminal.^[21]

Two things to know first. Claude Code needs a paid plan: Pro, Max, Ultra, Team or Enterprise.^[21] Pro is $20 billed monthly, or $17 a month billed yearly.^[19] Claude is available in Bangladesh.^[20] If $20 a month isn’t possible, the free-plan version is further down.

Build the BCS project folder

Spend one evening per subject collecting the material. This is the part that makes everything after it trustworthy:

• The current circular and syllabus from the PSC website. This is the boundary of what you study.
• Past questions, prelim and written, for as many recent BCS rounds as you can collect.
• Book chapters you own, one file per chapter. Don’t feed it pirated guide-book PDFs; besides the obvious problem, you can’t tell which edition’s mistakes you’re inheriting.
• Your lecture notes, or the transcript of a lecture if it comes with one.
• For Bangladesh affairs, the primary text where one exists, such as the constitution, not someone’s summary of it.
• For current affairs, a weekly set of dated newspaper articles you’ve picked yourself. An AI may not know last month’s news, and it may not tell you that it doesn’t.

Lay it out like this:

bcs-prep/
├── CLAUDE.md              your rules, read at the start of every session
├── syllabus/              circular and syllabus
├── past-questions/        prelim/, written/, one file per BCS round
├── books/                 one file per chapter, e.g. bd-affairs-ch03.pdf
├── lectures/              your notes and transcripts
├── current-affairs/       2026-11-02/, 2026-11-09/ ...
├── bank/                  checked questions, one file per topic
├── wrong-answers.md       every question you got wrong
└── .claude/
    ├── skills/            make-mcq/, mark-written/, viva-board/
    └── agents/            fact-checker.md

Scanned books need care. For files you upload to the Claude app, its help page says it reads both text and images in PDFs of up to 100 pages, but only the text in longer ones,^[30] and a scanned page is all image. Split scans into chapter files either way: a short file is easier to check page by page. Photograph pages straight and in good light: Claude’s own documentation warns it can make mistakes on low-quality, rotated or very small images.^[31] Before you trust a scanned chapter, ask Claude to type out one page and compare it word by word with the book. If it misreads the Bangla, type the key pages of that chapter yourself.

CLAUDE.md: the rules Claude reads every session

CLAUDE.md is a plain text file in the folder. Claude reads it every time you start working (a session),^[23] so you write your rules once instead of in every chat. Here’s a starting version:

# BCS prep: house rules

I'm preparing for the BCS preliminary and written exams.
Reply in Bangla unless I write in English.

## Sources
- Use only the files in this folder. If the answer isn't in them,
  say "not in my sources" and stop.
- Every fact you give me names its file and page,
  e.g. books/bd-affairs-ch03.pdf, p. 41.
- syllabus/ sets the limits. Don't go beyond it unless I ask.
- If two of my files disagree, show me both. Don't pick one.

## Questions
- Every question carries its source file, page and the exact line
  that proves the answer. No source line, no question.
- A question isn't checked until the fact-checker agent passes it.

## Me
- Read wrong-answers.md before you make any quiz,
  and lean towards the topics in it.

Claude Code also keeps notes of its own across sessions, called auto memory.^[23] They stay on your computer.^[23] Let it, but keep the things that matter (your rules, your wrong answers) in files you wrote and can read.

Skills: save the jobs you repeat

A skill is a SKILL.md file with instructions that Claude adds to what it can do.^[24] Project skills live in .claude/skills/<name>/SKILL.md, and you run one by typing / and its name, or Claude picks it up when it fits.^[24] The point is that the 40th quiz is made exactly like the first. Here’s the one you’ll use most:

---
name: make-mcq
description: Make BCS-style MCQs from one chapter in this folder, each with its source line
---

1. If I haven't said which file and pages, ask.
2. Read those pages only. Write 20 questions unless I give a number,
   in the style of the questions in past-questions/.
3. For each one write: the question, four options, the answer,
   the file, the page, and the exact line that proves the answer.
4. Send the list to the fact-checker agent. Keep only what it passes.
5. Save them to bank/<topic>.md marked "agent-checked".
   Show me the questions without answers, then wait for mine.

Two more are worth writing the same way. mark-written takes your handwritten answer, typed in, and marks it against a checklist you wrote (the points a full answer needs), listing what’s missing. viva-board plays an interview board, one question at a time with follow-ups, using your home district, subject, cadre choices and this week’s articles.

The fact-checker: a second Claude that only sees the page

Here’s the part a chat box can’t do. Claude Code can hand a task to a separate copy of Claude, called a subagent. Each one starts fresh, in its own context window, with its own instructions and its own tool access.^[25] A subagent does its work separately and sends back only the result.^[25] So the checker never sees how the questions were written. It isn’t marking its own homework.

---
name: fact-checker
description: Checks each BCS question against the page it cites. Use after any question is written.
tools: Read
---

For each question, open the cited file at the cited page.
Pass it only if the quoted line is really there, the line proves
the given answer, and no other option is also right.
Otherwise fail it and say why in one line.
Never use your own knowledge to pass a question.

Save that as .claude/agents/fact-checker.md. Every question then goes through the same line:

Know what this catches and what it doesn’t. The checker proves a question matches your book. It can’t prove your book is right, and guide books carry errors. For dates, figures and article numbers, check against the primary text or a dated news report before the batch gets your mark.

The same folder answers the “what do I study first” question. Ask Claude to tag every past question in past-questions/ with its syllabus topic, save the tags as a table, and count them. Check twenty tags by hand. The counts are your priority list, built from real papers instead of a coaching centre’s guess.

On the free plan: a smaller version

Claude’s free plan has Projects: up to five on a free account,^[28] each with its own uploaded files and its own instructions.^[28] Make one project per subject, upload the syllabus and a few chapters (project files can be up to 30MB each^[30]), and paste the rules from the CLAUDE.md above into the project instructions. Skills work on the free plan too, with code execution turned on in settings.^[29]

What you lose is the separate checker. Do it by hand: open a new chat, paste only the source page and the questions, and ask it to pass or fail each one against that page alone. Slower, same idea.

You don’t need MCP for any of this. MCP is an open standard for connecting Claude to other tools,^[26] and it matters if your material lives somewhere else: if your notes are in Google Drive, the Google Drive connector is available to all Claude users.^[27] A plain folder covers the rest.

Subject by subject: what to ask and what to check yourself

For the 50th BCS the preliminary marks changed: Bangla and English dropped to 30 each, Bangladesh affairs to 25, while international affairs rose to 25, mathematical reasoning to 20 and ethics to 15.^[6] The marks tell you where your hours should go. The table puts them beside the job that fits each subject.

A study loop that saves hours: test yourself, don’t reread

Rereading notes feels productive and isn’t. A 2013 review of ten study techniques gave the highest usefulness rating to just two: practice testing and spreading study out over time.^[17] An earlier experiment found that students who took a test on material remembered much more of it on a later test than students who spent the same time studying it again.^[18] Your checked question bank exists so you can test yourself. Use it that way.

The timed mock matters more than it looks. Prothom Alo’s list of the mistakes that cost candidates in the 47th BCS prelim hall puts this near the top: many spend too long on the first few questions and never get to the rest.^[14] With half a mark lost for every wrong answer,^[7] you also need a habit for when to skip. After each mock, count how many of your guesses were right. If it’s fewer than one in three, you’re losing marks by guessing, and you’ll see it in your own numbers.

Diagrams, timelines and animations: Claude writes the code

Claude doesn’t make pictures. Its own documentation says so: it can read images, but it can’t generate or edit them.^[31] What it can do is write the code that draws one. Mermaid, for example, turns a few lines of text into a diagram,^[33] and in the Claude app, diagrams and flowcharts can open in a panel beside the chat (an artifact) that you can save.^[32]

That’s better for studying than a generated image, because every label is text you can check. Use it like this:

1. Ask for the structure first, as text: “Turn this chapter into a timeline, one line each, year first.” Check it against the book.
2. Ask Claude to draw it from that checked outline only, as a Mermaid timeline or a diagram.
3. Ask for a second copy with every label blank. Print it and fill it in from memory. Then compare.

Step 3 turns a picture you’d look at once into a test, and testing is what makes it stick. One exception: don’t let an AI draw maps for you. A wrong label on a map you’ve stared at for a week is hard to unlearn. Use an atlas.

Animations, for the topics you keep getting wrong. Claude Code can also write animation code. Manim is a free, open-source library for maths animations,^[34] and Remotion builds videos from code, free for individuals,^[36] and says it works well with coding agents such as Claude Code.^[37] Mathematical reasoning is worth 20 marks, so if you keep losing marks on one problem type (trains, ratios, sets), ask for a short animation that solves one checked problem step by step, watch it, then solve two twin problems on your own.

Be honest about the cost. Manim’s install starts by opening a terminal,^[35] and Remotion needs Node.js installed.^[37] Claude’s own MP4 video export is only on Team and Enterprise plans.^[32] If setup eats more than an evening, skip it: drawing the same problem by hand, one step per line, teaches the same thing.

Written and viva practice with Claude

Written answers. Write your answer first, by hand and against a clock. Then type it in and run mark-written with your checklist: the points a full answer needs, the facts and the structure. Don’t ask it to write a model answer for you to memorise. You’d be learning its words, and maybe its mistakes.

Translation. Put ten Bangla sentences from a newspaper editorial in the folder and translate them into English yourself. Then ask for corrections, with the reason for each. Go the other way the next day. Add the mistakes you repeat to wrong-answers.md.

Mathematics. Ask for a worked solution only after you’ve tried. Then ask for a twin problem with different numbers and solve that alone. If Claude’s arithmetic and yours disagree, check with a calculator, not with Claude.

Viva. At 100 marks,^[8] the viva can still move you up or down the merit list. Run viva-board, answer out loud, and record yourself. Listen back once. You’ll hear the “uhh” and the rambling that no AI will point out.

Where the hours go instead

• Building the system forever. Set it up over one weekend. After that the folder changes only when you add a chapter or a week’s articles.
• Prompt fiddling. Rewriting a prompt five times to get a perfect summary is a way of avoiding the quiz.
• Chatting as studying. A long conversation about a topic feels like learning. Nothing goes into memory until you answer something without help.
• Asking it for current affairs. Read the news yourself and use Claude only to quiz you on what you read.

Set a timer for each session, say 25 minutes, and decide before you start what you’ll have at the end: 20 checked questions answered, one marked written answer, one blank-label timeline filled in.

The long wait, and the part you can control

The anxiety in BCS preparation isn’t only about the exam. It’s about years. One 43rd BCS candidate told Prothom Alo:

“Five years after passing, when I went to join, I was dropped without any reason.”^[11]

Back in 2021, the same paper wrote that young candidates were frustrated and in despair at how long each BCS took.^[13] And the job market outside the BCS isn’t kind either: Bangladesh had 8.85 lakh unemployed university graduates, and one in three graduates stayed jobless for up to two years while looking for work.^[15]

You can’t control the PSC’s timeline or the merit list. You can control how a study week feels. A few things help:

• Measure what you did, not what’s left. wrong-answers.md and your mock scores show progress the syllabus never will.
• Fix the hours, not the outcome. “Three focused hours, then stop” survives a bad day. “Finish international affairs this week” doesn’t.
• Let Claude hold the plan. Ask it to read wrong-answers.md and rebuild next week around your weak topics. Planning is the part anxiety makes hardest.
• Talk to a person. Claude can quiz you at 2 a.m. It can’t replace a friend who’s sat the exam, or someone you trust when the waiting gets heavy.

Your folder doesn’t go to waste if this round doesn’t work out. The checked bank and the wrong-answer file carry into the next BCS, and the Bangla, English and maths carry into whatever you do next.

FAQ

Pick one chapter you studied last week, put it in the folder, and run your first checked batch of 20. Your score tells you more about your preparation than another hour of rereading would.

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