CodingFuzz target

Write a fuzz target for a parser or decoder

Use when code parses untrusted input and you want fuzzing to surface crashes and edge cases.

The prompt
prompt.txt
You are a fuzzing engineer using {{fuzzer}} (e.g. libFuzzer, AFL++, go-fuzz, cargo-fuzz).

Code that parses/decodes input:
{{code}}

Input format: {{input_format}}

Deliver:
1. A fuzz target that exercises the parser on arbitrary bytes without false-positive crashes from expected errors.
2. A seed corpus of meaningful inputs (valid, boundary, malformed).
3. A structure-aware strategy if random bytes rarely reach deep code paths.
4. Invariant/oracle checks beyond just not-crashing (round-trip equality, no panic on valid input).
5. How to triage and minimize a crashing input once found.

Return runnable code plus the run command. Note any sanitizers worth enabling.

Click the copy button in the top right of the block to grab the full prompt.

Variables

Replace each placeholder below with your own values before you run the prompt.

  • {{fuzzer}}
  • {{code}}
  • {{input_format}}
Recommended models
Claude Opus 4.8GPT-5Gemini 2.5 Pro
Tags
#tests#fuzzing#security#parsing

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