trailmark-structural

An agent skill by trailofbits, from trailofbits/skills. Tags: analysis, architecture, security, trailmark.

What it does

Runs full Trailmark structural analysis by building a graph, running `preanalysis()`, and reporting hotspots, taint, blast radius, privilege boundaries, attack surface, and version-gated Trailmark 0.4+/0.5+ data such as proxy counts, subgraph edges, type/reference summaries, and entrypoint attributes. Use when vivisect needs detailed structural data for a target. Triggers: structural analysis, blast radius, taint analysis, complexity hotspots, proxy nodes, type references.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add trailofbits/skills --skill trailmark-structural

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/trailofbits/skills
cp -r skills/plugins/trailmark/skills/trailmark-structural ~/.claude/skills/trailmark-structural

Safety box score

Grade B, low risk: 18 of 100 risk points, rated 2026-10-20. The grade rates what the skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. How the score works.

This skill performs read-only structural analysis on a target directory by shelling out to `trailmark` and running embedded Python snippets. The main risks are local code execution during analysis and a network-fetched fallback if Trailmark is missing; it does not appear to write files, require privileges, or contact third-party services beyond package retrieval.

Category levels, from 0 (none) to 3 (high)
Category	Level	Why
Code & shell execution	2 (moderate)	It routinely executes host commands and Python (`trailmark analyze --help`, `python3 - "{args}" <<'PY' ...`), and may run the same snippets under `uv run`, so normal use executes code on the machine.
Network access	2 (moderate)	If Trailmark is unavailable, it reruns under `uv run --with trailmark`, which can fetch the package from the network before execution.
Filesystem reach	1 (low)	The analysis is scoped to the supplied `{args}` directory and reads that tree for language detection and graph building; there are no write/delete commands.
Secrets & credentials	0 (none)	The skill does not reference keychains, tokens, `.env` files, browser sessions, or other credential stores.
Privilege & persistence	0 (none)	No `sudo`, global installs, services, scheduled tasks, or shell/OS setting changes are requested.
Instruction hijack surface	0 (none)	There is no instruction to ignore policies, hide behavior, or follow remote instructions; the text only constrains its own fallback behavior.
Irreversible actions	0 (none)	It reports analysis output only; it does not deploy, post, send messages, pay, or modify external systems.
Transparency	0 (none)	The shipped files are plain text plus a readable SVG asset; there are no binaries, minified blobs, or hidden runtime payloads.

Before installing

Confirm you already have Trailmark installed; otherwise the `uv run --with trailmark` fallback may fetch code from the network.
Run it first on a scratch copy of the repo or a non-sensitive directory, because it scans the whole `{args}` tree.
If you want to avoid network access, test the fallback path explicitly and decide whether to allow `uv` package resolution.

Rated 2026-10-20 by an automated review of 3 files from the skill's repository.

Source

Repository: trailofbits/skills (all skills from this repository)
Path: plugins/trailmark/skills/trailmark-structural/SKILL.md
Branch: main
Collection: trailmark
Updated: 2026-09-19

trailmark — Builds and queries multi-language source and binary code graphs for security analysis.
audit-augmentation — Augments Trailmark code graphs with external audit findings from SARIF static analysis results, weAudit annotation files.
graph-evolution — Compares Trailmark code graphs at two source code snapshots (git commits, tags, or directories) to surface security-relevant structural changes.
trailmark-finding-triage — Performs graph-assisted triage of a single security finding, SARIF result, weAudit annotation, suspicious function.
trailmark-review-gate — Runs a Trailmark structural review gate over a branch, pull request, fix commit, release diff, or git ref range to detect new entrypoints, new tainted paths.
trailmark-summary — Runs a Trailmark summary analysis on a codebase. Returns auto-detected languages, entry point count, and dependency list.