Claude Code Verbose Mode Debugging Tips

When you’re building custom Claude skills or integrating AI assistance, understanding how to debug effectively is essential. Claude Code provides verbose mode options that expose the internal decision-making process, tool invocations, and intermediate reasoning steps that help you identify why a skill behaves unexpectedly.

This guide covers practical techniques for using Claude Code’s verbose mode to troubleshoot skill issues, trace execution flow, and optimize your AI-assisted development process.

Enabling Verbose Mode in Claude Code

Claude Code offers multiple levels of verbosity that reveal different amounts of internal information The primary flags you can use are --verbose and --debug, which control the detail level of output.

# Basic verbose output
claude --verbose

# Maximum debug information
claude --debug

# Combine with specific commands
claude --verbose "analyze this codebase"

For persistent configuration, you can set verbose mode in your Claude Code configuration file:

{
  "verbose": true,
  "logLevel": "debug",
  "logTools": true
}

The difference between these modes matters for debugging. Verbose mode shows reasoning steps and tool selections, while debug mode adds raw API responses and internal state information.

Tracing Skill Execution

When a custom skill behaves unexpectedly, verbose mode helps you trace exactly what the skill is doing. Consider a scenario where you’re using the tdd skill to generate tests but receiving unexpected results.

Enable verbose output to see:

Which tools the skill selects and why
The exact prompts being sent to the model
Tool execution results and timing
Any errors or warnings in the skill workflow

claude --verbose "generate tests for auth module"

The output reveals each step: initial prompt analysis, tool selection, file reads, test generation, and verification. When something goes wrong, this trace shows you exactly where the process diverged from expectations.

Debugging Tool Selection Issues

One common debugging scenario involves skills that select inappropriate tools. For instance, if you’re using the pdf skill to process documents but it attempts to use image processing tools instead, verbose mode shows the decision-making process.

Look for these patterns in verbose output:

[DEBUG] Evaluating tool candidates: Read, Bash, pdf_processor
[DEBUG] Selected tool: pdf_processor (confidence: 0.92)
[DEBUG] Reasoning: User requested PDF manipulation, pdf_processor matches intent

If you see unexpected tool selection, you can adjust your skill definition to constrain tool availability or refine the skill’s guidance prompts.

Analyzing Conversation Context

Verbose mode also exposes how Claude Code maintains conversation context, which helps when debugging issues with multi-turn conversations. This is particularly useful when working with skills like supermemory that manage persistent context across sessions.

The debug output shows:

Context window usage and token counts
Which previous messages are included in each request
Context truncation decisions
Memory retrieval and storage operations

claude --debug "continue our discussion about the API"

This information helps you understand why Claude might “forget” details or produce inconsistent responses across conversation turns.

Working with Frontend Design Skills

Debugging becomes more complex when working with visual skills like frontend-design or canvas-design, where the output is visual rather than textual. Verbose mode helps by showing the intermediate steps:

Design parameter extraction from your prompts
Style and layout decisions
Component hierarchy construction
Final rendering instructions

If a design skill produces unexpected results, the verbose trace shows exactly which decisions led to that output, allowing you to adjust your prompts accordingly.

Common Debugging Patterns

Here are practical patterns for common debugging scenarios:

Unexpected behavior in multi-step workflows:

claude --debug "complex task with multiple steps"
# Review each step's input/output in detail

Context or memory issues:

claude --debug "store this detail in memory"
# Observe memory operations in trace

API or network errors:

claude --debug "operation that failed"
# Examine raw API responses and error messages

Interpreting Verbose Output

The verbose and debug outputs can be overwhelming at first. Focus on these key sections:

Tool Selection: Shows which tools Claude chose and why
Execution Results: Shows what each tool returned
Reasoning Steps: Shows the model’s chain of thought
Errors and Warnings: Highlights issues requiring attention

When debugging skill issues, start with verbose mode (--verbose) and escalate to debug mode (--debug) only if you need more detail.

Optimizing Your Debug Workflow

Rather than running verbose mode constantly, use it strategically:

Enable verbose mode only when actively debugging
Redirect debug output to a file for later analysis: claude --debug task > debug.log 2>&1
Use grep to filter output: claude --debug task | grep -i error
Create aliases for common debugging scenarios:

alias claude-debug='claude --debug 2>&1 | tee debug-$(date +%Y%m%d-%H%M%S).log'

Integration with Skill Development

When developing custom skills, verbose mode becomes invaluable for:

Testing skill prompts and instructions
Verifying tool availability and permissions
Understanding model behavior with your skill
Iterating on skill improvements based on actual traces

The pdf skill, tdd skill, and other specialized skills all benefit from verbose debugging when you’re troubleshooting or optimizing their behavior.

Mastering Claude Code’s verbose mode transforms debugging from guesswork into systematic analysis. By understanding what happens inside the “black box,” you gain control over your AI-assisted development workflow and can build more reliable, predictable skill integrations.

Built by theluckystrike — More at zovo.one