trailofbits/trailmark-structural
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.
npx skills add https://github.com/trailofbits/skills --skill trailmark-structural
Builds a Trailmark graph and runs engine.preanalysis() to compute all
four pre-analysis passes. The core workflow is v0.2-safe; v0.4-only details
are included only after checking method availability, and newer builds
enrich the same output (0.5.0+ adds an attributes key to attack-surface
entries and proxy.external:* nodes from .trailmark/links.toml) without
any workflow change.
summaries when Trailmark 0.4.0+ is installed
trailmark-summary instead)trailmark skill directly)| Rationalization | Why It's Wrong | Required Action |
|-----------------|----------------|-----------------|
| "Summary analysis is enough" | Summary skips taint, blast radius, and privilege boundary data | Run full structural analysis when detailed data is needed |
| "One pass is sufficient" | Passes cross-reference each other — taint without blast radius misses critical nodes | Run all four passes |
| "Tool isn't installed, I'll analyze manually" | Manual analysis misses what tooling catches | Report "trailmark is not installed" and return |
| "Empty pass output means the pass failed" | Some passes produce no data for some codebases (e.g., no privilege boundaries) | Return full output regardless |
| "A v0.4 field is always present" | Users may still have Trailmark 0.2.x installed | Probe with hasattr() before querying v0.4-only methods |
The target directory is passed via the args parameter.
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:
trailmark --version 2>/dev/null || uv run trailmark --version 2>/dev/null || true
Do not fail if this command is missing; use API feature probes below.
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 full structural analysis via QueryEngine.
Run this snippet with python3. If the import fails, rerun the same snippet
under uv run python - "{args}".
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
from trailmark.query.api import QueryEngine
target = sys.argv[1]
languages = detect_languages(target)
engine = QueryEngine.from_directory(target, language="auto")
preanalysis = engine.preanalysis()
def summarize_subgraph(name: str, limit: int = 25) -> dict[str, object]:
nodes = engine.subgraph(name)
summary = {
"count": len(nodes),
"sample_ids": [node["id"] for node in nodes[:limit]],
}
if hasattr(engine, "subgraph_edges"):
summary["edge_count"] = len(engine.subgraph_edges(name))
return summary
graph = json.loads(engine.to_json())
nodes = graph.get("nodes", {})
proxy_nodes = [
node_id for node_id, node in nodes.items()
if node.get("kind") == "proxy" or node.get("origin") == "proxy"
]
payload = {
"languages": languages,
"summary": engine.summary(),
"preanalysis": preanalysis,
"attack_surface": engine.attack_surface()[:25],
"hotspots": engine.complexity_hotspots(10)[:25],
"proxy_nodes": proxy_nodes[:25],
"subgraphs": {
name: summarize_subgraph(name)
for name in engine.subgraph_names()
},
}
if hasattr(engine, "type_references"):
payload["type_reference_samples"] = {
node_id: engine.type_references(node_id)[:10]
for node_id in list(nodes)[:25]
}
print(json.dumps(payload, indent=2))
PY
Step 4: Verify the output.
The output should include:
languagessummarypreanalysishotspots (possibly empty)proxy_nodes (empty on v0.2.x or when there are no unresolved calls; on0.5.0+ may include proxy.external:* entries declared in
.trailmark/links.toml)
subgraphs with counts and sample IDsOn Trailmark 0.5.0+, attack_surface entries may carry an attributes
object (e.g. solidity_visibility, solidity_overridden_by). Pass it
through unchanged — downstream consumers use it to rank entrypoints.
Some subgraphs may have zero nodes for some codebases (this is
normal). Return the full JSON payload regardless.
Take trailofbits/trailmark-structural from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.
The instructions reference pip, uv.
Without those the skill loads but fails at the first command.