Debugging
Paste the failing code and the full error. Ask for the root cause first, then the fix, so you learn why it broke.
use-cases/coding
Use case · software engineering
Coding with GLM-5
Coding is what the GLM-5 family is built for. Z.ai positions GLM-5.3 for complex software engineering and long agent tasks, and its million-token context lets you paste whole modules instead of fragments. Here is how to get the most out of it.
Which modelGLM-5.3Use GLM-5.3 for debugging, refactoring and architecture questions — it is Z.ai's strongest coding model in our chat. Use GLM-5.3 Flash for quick snippets, explanations and screenshots of errors, since it reads images.
§ 01What it does well
Where GLM-5 helps most
Code review
Give it a diff or a file and ask for bugs, edge cases and security issues, ranked by severity.
Refactoring
Describe the goal — smaller functions, clearer names, fewer dependencies — and ask for a step-by-step plan before code.
Tests and docs
Ask for unit tests that cover edge cases, or for a README and docstrings that match the code you pasted.
§ 02Prompts
Copy-ready prompts
Open any prompt in the chat, then replace the bracketed parts with your own material.
Find the bug
Here is a function and the error it throws. Explain the root cause in two sentences, then give a corrected version and one test that would have caught it. Code: [paste code] Error: [paste error]
Review a diff
Act as a strict senior reviewer. Review this diff for bugs, edge cases, security problems and readability. List issues by severity (high, medium, low) with line references, then suggest fixes. [paste diff]
Plan a refactor
I want to refactor this module to make it easier to test. First propose a step-by-step plan with the reasons for each step. Do not write code until I approve the plan. [paste module]
§ 03Tips
Do this, avoid that
Do
- Include the language, framework and version.
- Paste the exact error message and stack trace.
- Ask for a plan before a large change.
- Run the tests yourself before you trust a fix.
Avoid
- Do not paste secrets, keys or customer data.
- Do not accept code you do not understand.
- Do not ask for an entire app in one message.
- Do not skip review of generated security code.
§ 04FAQ
Questions
Q01Which GLM model is best for coding?
In our chat, GLM-5.3. Z.ai built it for complex software engineering and reports large coding gains over GLM-5.2. GLM-5.3 Flash is a fast, free-flowing alternative for smaller tasks.
Q02Can I paste a whole repository?
GLM-5.3 supports about one million tokens of context through the API. Our free chat trims very long conversations to keep requests fast, so paste the files that matter most.
Q03Can it read a screenshot of an error?
Yes, with GLM-5.3 Flash. Attach the screenshot and ask what went wrong.
§ 05More
Other use cases
Try it now
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