How to Use an AI Coding Assistant (Step by Step)
A guide to Phase 1 — Set Up a Useful Session, Phase 2 — Generate and Understand the Code, Phase 3 — Test and Fix, Phase 4 — Secure and Document What You Keep
A coding assistant will produce a plausible patch in seconds, but it does not know your project's conventions, your framework version or what your users actually need. Your job shifts from typing to directing and reviewing. This guide covers 28 concrete steps, from choosing which files to put in context to running a clean build before you call the work done. The habit that separates productive use from expensive cleanup is simple: never merge a line you cannot explain or a change you have not watched pass a test. Browse all illustrated guides or the AI Coding & Development category for more illustrated walkthroughs on Howcompass.
How do you use an AI Coding Assistant (Step by Step)?
Howcompass | How to Use an AI Coding Assistant (Step by Step)Phase 1 — Set Up a Useful Session
HowcompassOpen the relevant files, not the whole repository
Open the relevant files, not the whole repository. Give the assistant the two or three files directly involved in the task. A focused context produces sharper suggestions and keeps private code out of the prompt; a whole-repo dump does the opposite. For the primary source behind this phase, see Anthropic — AI research and documentation.
HowcompassState the goal and constraints in one paragraph
State the goal and constraints in one paragraph. Say what the change must achieve, the language and framework version, and which parts must not be touched. Including the exact version prevents suggestions built on APIs your project does not have.
HowcompassPaste the exact error and stack trace
Paste the exact error and stack trace. When debugging, supply the full error text with its exception type and line numbers instead of saying 'it does not work'. Precise symptoms turn the assistant's job from guessing into matching a known cause.
HowcompassAgree on a style contract
Agree on a style contract. Specify naming conventions, whether to add comments, and which test framework to use. Code that follows the existing house style is far easier to review and merge than a clever but foreign rewrite.
HowcompassMatch the mode to the task
Match the mode to the task. Use inline completion for a small edit, chat for a discussed change, and agent mode for a scoped multi-file task. Picking the right mode saves more time than writing a longer prompt ever will.
HowcompassSet an explicit scope boundary
Set an explicit scope boundary. Tell it 'modify only this function' or 'do not change the tests' before it starts. A scope lock stops a small request from quietly turning into a whole-file rewrite you then have to untangle.
HowcompassKeep secrets out of the prompt
Keep secrets out of the prompt. Replace API keys, tokens and production connection strings with placeholders before sending code. Prompts are stored and reviewed, so a real credential pasted once is a credential that has leaked. Related on Howcompass: use AI for content marketing.
Phase 2 — Generate and Understand the Code
HowcompassRequest a plan before the code
Request a plan before the code. Ask for a few lines describing the intended approach and which files it will touch, then approve the direction. Reading the plan first lets you stop a wrong solution before it spreads across several files. For the primary source behind this phase, see Microsoft Learn.
HowcompassAsk for one function at a time
Ask for one function at a time. Generate a single function or block per request rather than a whole module. Small pieces are easier to verify, and when something breaks you can point to the exact addition responsible.
HowcompassRequest an explanation of the tricky lines
Request an explanation of the tricky lines. For an unfamiliar algorithm or library call, have it explain why each line is written that way. Do not accept code you cannot read — you, not the model, will be maintaining it next year.
HowcompassAsk it to copy the existing pattern
Ask it to copy the existing pattern. Point to a similar function already in the project and ask it to follow that structure. Consistency with the codebase usually matters more than a theoretically tidier approach. Browse all illustrated guides or the AI Coding & Development category for more.
HowcompassDiff every suggestion against your file
Diff every suggestion against your file. Read the diff line by line and look for unrelated lines that were altered and new dependencies that appeared. Clicking 'accept all' hands your review responsibility to the tool that wrote the code.
HowcompassCheck imports and version compatibility
Check imports and version compatibility. Confirm each imported package is installed and that the API exists in your pinned framework version. Outdated API calls are a classic reason code passes locally then fails in a clean or production environment.
HowcompassReject code you cannot explain
Reject code you cannot explain. If one branch of the logic is unclear, ask for a rewrite or check the official docs yourself. An opaque patch is a liability that grows, because nobody will dare touch it when the requirements change. Related on Howcompass: build a no-code AI automation.
Phase 3 — Test and Fix
HowcompassRun the existing test suite first
Run the existing test suite first. Establish a green baseline before adding anything, so a later failure is unambiguously yours. If the starting suite is already red, fix that first or you will never know whether the new change helped. For the primary source behind this phase, see NIST — AI Risk Management Framework.
HowcompassWrite a test for the new behaviour
Write a test for the new behaviour. Have the assistant add one test covering this change, with a normal input and one boundary value. A test converts 'looks right to me' into a result you can re-run after every future edit.
HowcompassExercise the failure path explicitly
Exercise the failure path explicitly. Run it with an empty input, an oversized string and a dropped connection, since assistants tend to cover only the happy path. Untested error handling is the most common source of production crashes in generated code.
HowcompassMeasure performance if the code is hot
Measure performance if the code is hot. Time any loop, query or frequently called function, because a generated solution can be correct yet an order of magnitude slower. A quick benchmark before merging is much cheaper than a production slowdown.
HowcompassFeed the real error back, not a guess
Feed the real error back, not a guess. Paste the complete failing-test output verbatim so the next attempt works from evidence. Exact error text often cuts the number of retry rounds from five or six down to one or two.
HowcompassCap the retry loop at three attempts
Cap the retry loop at three attempts. If the same problem survives two or three rounds of tweaks, stop and reread the documentation or edit it yourself. Repeated blind patches usually make the code more convoluted, not more correct.
HowcompassAsk for a simpler rewrite
Ask for a simpler rewrite. When fixes keep piling up, request a version with fewer dependencies and fewer branches. A deliberate simplification is frequently faster and produces code that is easier to maintain. Related on Howcompass: use AI for content marketing.
Phase 4 — Secure and Document What You Keep
HowcompassScan for injection and unsafe calls
Scan for injection and unsafe calls. Inspect string-built SQL, directly rendered HTML and shell commands built from arguments, then parameterise or escape them. Models often reach for the shortest working form, which is also the least safe one. For the primary source behind this phase, see Mozilla — web and browser resources.
HowcompassVerify any package it recommends
Verify any package it recommends. Before installing a new dependency, check its maintenance activity, download count and licence. Assistants occasionally cite a package that is abandoned or does not exist under that name.
HowcompassReplace generated credentials and endpoints
Replace generated credentials and endpoints. Turn any hardcoded key, internal URL or sample token into a configuration value or environment variable. Such values pass tests happily and then cause incidents the moment the code reaches production.
HowcompassComment only where the intent is unclear
Comment only where the intent is unclear. Explain why a non-obvious decision was made, not what a readable line already says. Comments that restate the code simply rot the moment the implementation changes.
HowcompassUpdate the type hints and documentation
Update the type hints and documentation. Add the new parameters, return types and usage notes so the next developer need not reverse-engineer them. Keeping the signature and docs accurate is part of the change, not an optional extra.
HowcompassRecord the prompt behind tricky code
Record the prompt behind tricky code. For a hard-to-follow generated block, include the key prompt and the tool version in the commit message. When someone later asks why it was written that way, the reasoning is still recoverable.
HowcompassRun a final clean build
Run a final clean build. Reinstall dependencies in a clean environment and run the full test and lint checks. Passing only on your machine means you relied on some accidental local state, and the work is not yet finished. Related on Howcompass: build a no-code AI automation.
Frequently Asked Questions
Question: Can an assistant write production-ready code?
It can produce a strong first draft, but production-readiness comes from your review, tests, security checks and a clean build. Treat the output as a proposal written by a fast junior developer who needs supervision.
Question: What context should I give it?
Supply the two or three directly relevant files, the exact error text, your framework version and any style rules. Focused context beats a full repository dump for both accuracy and confidentiality.
Question: Do I still need to understand the generated code?
Yes. You are responsible for maintaining and debugging it long after the session ends, so any line you cannot explain is a line to rewrite or look up before it is merged.
Warnings
- Accepting a diff without reading it: Generated patches often change more than you asked, including imports and unrelated lines; walking the diff is the only reliable way to know what will actually ship.
- Pasting secrets into the prompt: Prompts are logged and may be retained or reviewed, so a real API key or connection string pasted once should be treated as compromised and rotated immediately.
- Letting retry loops run unchecked: Asking the model to 'try again' repeatedly without a new error message tends to produce increasingly convoluted code; stop after a few attempts and investigate the root cause yourself.
Related Howcompass Guides
References (4)
- Anthropic — AI research and documentationanthropic.com
- Microsoft Learnlearn.microsoft.com
- NIST — AI Risk Management Frameworknist.gov
- Mozilla — web and browser resourcesmozilla.org
Sources are listed so you can read the underlying guidance yourself. Our editorial policy explains how guides are reviewed.
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