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Trailmark Summary

Free

Quickly analyze codebase structure with Trailmark.

by trailofbits6.5k stars on trailofbits/skills
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Updated Aug 10, 2026
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Free · Opens the source repo

What Trailmark Summary does

Trailmark Summary is a skill designed for developers and security analysts who need to quickly assess the structure of a codebase. By running the command trailmark analyze --language auto --summary, this skill provides essential information including detected programming languages, the count of entry points, and a list of dependencies. This is particularly useful during the early phases of code analysis, such as when using tools like Vivisect or Galvanize, where a rapid overview is needed before deeper investigation.

The skill operates by first checking if Trailmark is installed and accessible. It leverages Trailmark's parsing capabilities to automatically detect languages used in the codebase, ensuring that the analysis is accurate and comprehensive. The output includes critical details that are necessary for understanding the code's structure, making it easier for developers to identify potential areas of interest or concern without diving into the code manually.

This skill is especially beneficial when dealing with unfamiliar codebases, where a quick structural overview can inform subsequent analysis steps. It helps streamline the process of gathering foundational information, allowing users to focus on more complex tasks without getting bogged down in initial assessments.

However, it is important to note that Trailmark Summary is not a substitute for a full structural analysis. Users needing detailed insights or specific metrics, such as hotspot scores or taint data, should utilize the full Trailmark capabilities instead. This skill is intended for quick assessments rather than exhaustive evaluations, making it a practical addition to a developer's toolkit when time and efficiency are critical.

When to use it

Use this skill for quick assessments during initial code analysis phases or when encountering unfamiliar codebases.

When not to use it

Avoid using this skill for comprehensive structural analysis or when detailed metrics are required; opt for the full Trailmark tool instead.

What you can build with it

Initial Code Review

Quickly assess the structure of a new codebase before diving into detailed analysis.

Dependency Check

Get a rapid overview of dependencies in a project to identify potential issues.

Language Detection

Automatically detect programming languages used in a codebase to inform further analysis.

How to install Trailmark Summary

View source

1. Install with the skills CLI

npx skills add trailofbits/skills/trailmark-summary --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by trailofbits

Trailmark Summary

Runs trailmark analyze --language auto --summary on a target directory. This is a v0.2-safe workflow; do not require Trailmark 0.4.0 just to produce a summary.

When to Use

  • Vivisect Phase 0 needs a quick structural overview before decomposition
  • Galvanize Phase 1 needs detected languages and entry point count
  • Quick orientation on an unfamiliar codebase before deeper analysis

When NOT to Use

  • Full structural analysis with all passes needed (use trailmark-structural)
  • Detailed code graph queries (use the main trailmark skill directly)
  • You need hotspot scores or taint data (use trailmark-structural)

Rationalizations to Reject

RationalizationWhy It's WrongRequired Action
"I can read the code manually instead"Manual reading misses parser-based language detection, dependency data, and entry point enumerationInstall and run trailmark
"Language detection doesn't matter"Wrong language selection produces empty or partial analysisUse Trailmark's parser-based detection or --language auto
"Partial output is good enough"Missing any of the three required outputs (detected languages, entry points, dependencies) means incomplete analysisVerify all three are present
"Tool isn't installed, I'll skip it"This skill exists specifically to run trailmarkReport the installation gap instead of skipping

Usage

The target directory is passed via the args parameter.

Execution

Step 1: Check that trailmark is available.

trailmark analyze --help 2>/dev/null || \
  uv run trailmark analyze --help 2>/dev/null

If neither command works, report "trailmark is not installed" and return. Do NOT run pip install, uv pip install, git clone, or any install command. The user must install trailmark themselves.

Optionally record the version if the installed build supports it:

trailmark --version 2>/dev/null || uv run trailmark --version 2>/dev/null || true

Do not fail if the version command is missing; older v0.2.x builds may still support the summary workflow.

Step 2: Detect languages with Trailmark's parse API.

python3 - "{args}" <<'PY'
import json
import sys

try:
    from trailmark.parse import detect_languages  # canonical location since 0.3.x
except ModuleNotFoundError:
    # v0.2.x predates trailmark.parse; the same function lives in query.api
    from trailmark.query.api import detect_languages

print(json.dumps(detect_languages(sys.argv[1])))
PY

If the import fails, rerun the same snippet with uv run python - "{args}". If the result is [], report "Trailmark found no supported languages under target" and return.

Step 3: Run the summary with auto-detection.

trailmark analyze --language auto --summary {args} 2>&1 || \
  uv run trailmark analyze --language auto --summary {args} 2>&1

Step 4: Verify the output.

The output must include ALL THREE of:

  1. Detected languages from Step 2
  2. Entrypoints: line from the summary output
  3. Dependencies: line from the summary output

If any are missing, report the gap. Do not fabricate output.

Return the detected language list plus the full Trailmark summary output. If a version string was available, include it in the returned metadata.

Frequently asked questions about Trailmark Summary

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