An AI coding prompt generator for bug reports, diffs and tests
This AI coding prompt generator packages a programming request the way a good bug report would: the language and versions, the code in a fenced block, the exact error, what you expected and what happened, the steps to reproduce, test cases, your constraints and the kind of answer you want back — a diff, a full file or an explanation.
Choose one of seven task types — write, refactor, debug, explain, write tests, review or convert — or one of nine templates. The checklist walks through a reproducible bug report, warns when a snippet looks like it contains a password or API key, and flags conflicting instructions. The prompt works with ChatGPT, Claude, Gemini or an assistant in your editor.
How to write a coding prompt
- Pick a Task type or a template.
- Enter the Language and Framework, libraries and versions, and describe what you want.
- Paste the Code; for a bug, add the Error message or log, expected and actual behaviour and the steps to reproduce.
- Add test cases, tick constraints such as No new dependencies and choose the Expected output.
- Fix what the checklist flags, then copy the prompt as text, Markdown or JSON.
AI Coding Prompt Generator features
Seven task types
Each sets the role and a default task — for debugging, “find the root cause before changing anything”.
Fences that survive
Code and logs go in fenced blocks tagged with the language; code that contains ``` gets a longer fence.
Bug-report checklist
Error text, expected and actual behaviour, steps, versions and a minimal sample.
Secret detector
Flags API keys, tokens, private keys and password assignments before you paste them anywhere.
Six answer formats
Unified diff, full file, changed functions, an explanation, a ranked issue list, or a plan first.
Template-safe
Code and logs are never scanned for {{variables}}, so Vue, Jinja or Handlebars syntax is left alone.
What makes a coding prompt reproducible
Stack Overflow’s guide to a “minimal, reproducible example” works for AI prompts too, because the model, like a stranger on a forum, knows only what you paste:
- Minimal — as little code as possible that still produces the same problem.
- Complete — everything needed to reproduce it, in the question itself.
- Reproducible — test the snippet, say what should happen, and give the exact error and the line that produces it.
The debug checklist follows that: error message, expected and actual behaviour, steps to reproduce, versions, and a warning past 150 lines of code.
Diff, full file or explanation?
| Expected output | Best for | Watch out for |
|---|---|---|
| Unified diff | Small fixes in a larger file | Check the context lines before applying |
| Complete file | Short files, refactors, conversions | Long files cost tokens and may be cut off |
| Changed functions only | Features in a big module | You merge by hand |
| Explanation only | Learning and legacy code | No code changes |
| Issues, most severe first | Reviews before merging | Ask for line numbers |
| A plan first | Risky or multi-file changes | Needs a second message |
Compare the AI’s version with yours in the diff checker before you commit it.
Vendor advice built in
Anthropic’s prompting guide (checked 14 October 2026) says some Claude models tend to over-engineer — extra files, abstractions and options nobody asked for — and suggests limiting changes to what was requested; Smallest change only adds that line. It also warns against code written just to pass the given tests, so listing test cases adds a request for code that is correct for all valid inputs. OpenAI’s Help Center notes that “leading words” such as import or SELECT steer the model to the right language; naming the language and tagging the fence does the same.
Never paste production secrets. The check looks for common key formats (sk-, AKIA, ghp_, xox, AIza), private-key headers and lines like password = "…" — a pattern match, not a guarantee.
Worked example
The start example — a Python function that crashes on an empty list — produces this prompt:
You are a senior Python developer. Find the root cause before changing anything, and explain it. If something you need is missing, ask for it instead of guessing.
Task:
Fix the crash when the list is empty.
Environment:
- Language: Python
- Framework, libraries and versions: Python 3.12
Code:
```python
def average(values):
return sum(values) / len(values)
print(average([]))
```
Error message:
```text
Traceback (most recent call last):
File "stats.py", line 4, in <module>
print(average([]))
File "stats.py", line 2, in average
return sum(values) / len(values)
ZeroDivisionError: division by zero
```
Expected behaviour:
average([]) returns 0.0 instead of crashing.
Actual behaviour:
It raises ZeroDivisionError.
Steps to reproduce:
1. Run python stats.py
Test cases:
- average([2, 4]) → 3.0
- average([]) → 0.0
Constraints:
- Do not add new dependencies; use only the standard library and what the project already uses.
- Make the smallest change that does the job. Do not refactor unrelated code or add features nobody asked for.
- Make the code correct for all valid inputs, not only these test cases; never hard-code expected results.
Expected output:
Reply with a unified diff of your changes (as git diff would show them), then a short explanation of what you changed and why.AI Coding Prompt Generator FAQ
How do I ask AI to fix a bug?
Give it the language and versions, the smallest code that shows the bug, the exact error, what you expected, what happened and how to reproduce it, then say what answer you want. This AI coding prompt generator lays that out and checks what is missing.
Should I paste my whole file?
Usually not. Cut it down to the function and the inputs that trigger the problem; a short, complete sample gets a more focused answer. Ask for a complete file only when the file is short.
Is it safe to paste code into an AI chat?
Treat it like posting on a public forum unless your company has approved the tool. Remove passwords, keys, customer data and anything confidential; the secret check helps but cannot catch everything.
Does this page run or upload my code?
No. It only arranges your text into a prompt, in your browser. Nothing is executed or uploaded.
Which AI is best for coding?
Why are my {{ }} braces not turned into variables?
Code and logs are never scanned, so Vue, Angular, Jinja or Handlebars syntax stays exactly as pasted. Variables still work in the description and context boxes.