Reducing Token Usage While Debugging in Lovable

Why debugging in Lovable burns through credits quickly

Debugging is the single biggest credit drain in Lovable. A typical feature implementation might cost 1-3 credits, but fixing a stubborn bug can consume 10-20+ credits if the AI gets stuck in a loop. This happens because each Agent Mode prompt executes code changes — and when a fix attempt fails, the AI tries again, modifying more files, potentially introducing new bugs, and burning another credit each time. The 'looping' problem is Lovable's most reported issue. The AI attempts a fix, it does not work, so it tries a different approach, which breaks something else, so it tries to fix that — and the cycle continues until you run out of credits or manually stop it. Complex projects with many interconnected components are especially prone to this pattern because a change in one file can cascade into errors across multiple others. The key to reducing token usage is changing your debugging approach. Instead of letting Agent Mode repeatedly attempt fixes, use Plan Mode for diagnosis, the Try-to-fix button for free quick fixes, and precisely scoped prompts that target specific files and lines. This shift in strategy can reduce your debugging credit usage by 70% or more.

• AI fix loops — the AI repeatedly fails to fix the same bug, burning credits with each attempt
• Vague debugging prompts — 'fix the errors' triggers broad changes across multiple files
• Not using Plan Mode — Agent Mode modifies code on every prompt, Plan Mode only analyzes
• Ignoring the Try-to-fix button — this free feature resolves many common errors without credits
• Not reverting early — continuing to debug on top of broken code compounds the problem

Error messages you might see

Before you start

• A Lovable project with a bug you need to debug
• Understanding of Plan Mode vs Agent Mode (the mode toggle above the chat input)
• Access to the browser console (F12) to read exact error messages

How to fix it

// Credit-burning approach: Agent Mode guessing
// Prompt: "Fix the errors in my dashboard page"
// Result: AI modifies 5 files, introduces new bugs, costs 3+ credits
// Then: "Fix the new errors"
// Result: AI modifies 3 more files, costs 2 more credits
// Total: 5+ credits, problem may still not be fixed

// Credit-efficient approach: Plan Mode diagnosis first
//
// Step 1 (Plan Mode, 1 credit):
// "I see this error in the console:
//  TypeError: Cannot read properties of undefined (reading 'email')
//  at UserProfile.tsx:24
//  What is causing this and what is the minimal fix?"
//
// Plan Mode response: "The user object is undefined because the
// useEffect that fetches user data has not completed yet.
// Fix: Add a loading check on line 24."
//
// Step 2 (Agent Mode, <1 credit):
// "In @src/components/UserProfile.tsx, add a null check for the user
//  object on line 24. Show a loading spinner while user data is being
//  fetched. Do not change any other files."
//
// Total: ~2 credits, targeted fix, no side effects

// Broad prompt — AI searches everything, modifies multiple files
// "Fix the TypeError in my app"
// Credits: 2-5 (depending on how many files it touches)

// Scoped prompt — AI changes one file, one line
// "In @src/components/UserProfile.tsx line 24,
//  the user object can be undefined when the component
//  first renders. Add: if (!user) return <Spinner />;
//  before the line that accesses user.email."
// Credits: <1

// Fix loop pattern — each attempt costs credits and makes things worse
// Attempt 1: "Fix the error" → new error appears → 1 credit
// Attempt 2: "Fix the new error" → breaks something else → 1 credit
// Attempt 3: "Fix all the errors" → reverts attempt 1 → 2 credits
// Attempt 4: "The original error is back" → tries a different approach → 1 credit
// Total: 5+ credits, still broken

// Efficient pattern — revert and rethink after 2 failures
// Attempt 1: "Fix the error" → does not work → 1 credit
// Attempt 2: "Try a different approach" → does not work → 1 credit
// STOP. Revert to last working version → 0 credits
// Plan Mode: "Analyze this error without changing code" → 1 credit
// Agent Mode: Execute the precise fix from Plan Mode → <1 credit
// Total: ~3 credits, fixed correctly

// Using Agent Mode for a simple color change — costs a credit
// "Change the header background color to blue-600"

// Using Visual Edits — costs zero credits
// 1. Click + next to Preview → Design view → Visual Edits tab
// 2. Click on the header element in the preview
// 3. Change the background color to blue-600 using the color picker
//
// Or using Dev Mode — costs zero credits
// 1. Open Dev Mode (click + next to Preview → Code)
// 2. Navigate to the header component file
// 3. Change bg-white to bg-blue-600 directly
// 4. Changes take effect immediately in the preview

Complete code example

1# Credit-Efficient Debugging Rules
2
3## Fix Attempt Limits
4
51. If a fix attempt fails, do NOT retry automatically.
62. After a failed fix, STOP and explain:
7   - What you tried
8   - Why it failed
9   - What the root cause likely is
10   - What you would try next (but do not execute)
113. Maximum 2 fix attempts per bug before stopping.
124. If the same error reappears after 2 attempts, suggest reverting.
13
14## Change Scope Rules
15
161. Only modify files explicitly mentioned in the prompt.
172. Do not refactor adjacent files unless asked.
183. For bug fixes, change the minimum number of lines possible.
194. List all files you plan to modify BEFORE making changes.
20
21## Debugging Protocol
22
231. First, read the error message and trace it to the source file.
242. Explain the root cause before proposing a fix.
253. Propose the smallest possible change.
264. If the fix requires changes to more than 3 files, ask for confirmation.
27
28## Never
29
30- Never rewrite an entire component to fix a single bug
31- Never install new packages as part of a bug fix
32- Never modify vite.config.ts unless the error specifically points to it
33- Never change authentication or database configuration as a side effect

Best practices to prevent this

• Always click the free Try-to-fix button before spending credits on manual debugging prompts
• Use Plan Mode to diagnose bugs before Agent Mode to fix them — analysis is cheaper than trial-and-error
• Reference specific files and line numbers in prompts using @ syntax to limit the scope of AI changes
• Stop after two failed fix attempts and revert to the last working version — continuing burns credits without progress
• Use Visual Edits and Dev Mode for simple changes — they cost zero credits
• Add the credit-efficient debugging rules from AGENTS.md to your project to prevent AI fix loops
• Copy the exact error message from the browser console into your prompt — vague descriptions cost more credits
• Track your credit usage in account settings and set a mental budget per debugging session

Still stuck?

Copy one of these prompts to get a personalized, step-by-step explanation.

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