Semgrep
vigolium/piolium
Run Semgrep static analysis scan on a codebase using parallel subagents.
Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common…
Install Trailmark Variant Neighborhood
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install trailofbits/skills trailmark-variant-neighborhood --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .claude/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .claude/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhoodType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install trailofbits/skills trailmark-variant-neighborhood --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .agents/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .agents/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install trailofbits/skills trailmark-variant-neighborhood --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .cursor/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .cursor/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/trailofbits/skills.git --path plugins/trailmark/skills/trailmark-variant-neighborhood--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install trailofbits/skills trailmark-variant-neighborhood --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .gemini/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .gemini/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install trailofbits/skills trailmark-variant-neighborhoodInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .github/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .github/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install trailofbits/skills trailmark-variant-neighborhood --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/trailofbits/skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/trailmark/skills/trailmark-variant-neighborhood .opencode/skills/trailmark-variant-neighborhood && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "trailmark-variant-neighborhood" agent skill from https://github.com/trailofbits/skills/tree/main/plugins/trailmark/skills/trailmark-variant-neighborhood into .opencode/skills/trailmark-variant-neighborhood/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "trailmark-variant-neighborhood", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
trailmark-variant-neighborhood- GitHub stars
- 7.5k
- Token cost
- ~1.1k tokens
- SKILL.md length
- 431 words
- Files
- 6 (incl. references, assets)
- Skills in repo
- 79
- Repo updated
- First seen
- Licence
- CC-BY-SA-4.0
At a glance
Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common…
- Works in 5 steps: Normalize And Bind The Seed → Expand Neighborhoods → Rank Candidates → …
- Tasks that involve Static analysis and SAST
- SKILL.md covers When to Use, When NOT to Use, Rationalizations to Reject and Workflow, plus 1 more section
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Trailmark Variant Neighborhood is an agent skill from trailofbits/skills, published by the product's own GitHub organization. Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common entrypoint paths, interface implementations, override relationships, type/reference neighbors, and structurally similar nodes. Use after one issue is found to seed variant-analysis, semgrep-rule-creator, static-analysis, or manual review with graph-derived candidate locations.
Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 8 other files, including reference files and assets (for example `agents/openai.yaml`, `references/neighborhood-patterns.md` and `references/output-format.md`).
It sits in Security, covering Static analysis and SAST. It works with Semgrep. The repository describes itself as: Trail of Bits Claude Code skills for security research, vulnerability detection, and audit workflows. The licence is CC-BY-SA-4.0.
When your agent uses it
- Tasks that involve Static analysis and SAST
Example prompts
- “Use the trailmark-variant-neighborhood skill to expand one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant…”
- “/trailmark-variant-neighborhood”
Requirements
- Pre-approved tools (allowed-tools): Bash, Read, Grep, Glob, Write
Workflow steps
5 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 442fc9d. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
BashReadGrepGlobWrite
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Trailmark Variant Neighborhood loads about 1.1k tokens when it runs, and up to ~2.4k if it reads all its reference files. Until then it costs about 126 tokens; SKILL.md has 431 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Bash, Read, Grep, Glob, Write
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from trailofbits/skills at commit 442fc9d, republished under its CC-BY-SA-4.0 licence (© trailofbits). 431 words, ~1,073 tokens.
Download SKILL.mdSave it as
.claude/skills/trailmark-variant-neighborhood/SKILL.md (or your agent's skills folder). This skill also uses 5 other files; get the full folder from GitHub.- name
- trailmark-variant-neighborhood
- description
- Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common entrypoint paths, interface implementations, override relationships, type/reference neighbors, and structurally similar nodes. Use after one issue is found to seed variant-analysis, semgrep-rule-creator, static-analysis, or manual review with graph-derived candidate locations.
- allowed-tools
- Bash, Read, Grep, Glob, Write
Trailmark Variant Neighborhood
Expand one seed issue into graph-derived variant candidates. This skill generates review targets, not confirmed findings.
When to Use
- A finding is confirmed or plausible and variants may exist
- The vulnerable pattern depends on call context
- The issue involves a shared sink, source, validator, interface, override, trait, hook, handler, adapter, or critical type
- The next step is to seed
variant-analysis,semgrep-rule-creator,static-analysis, or manual review
When NOT to Use
- No seed issue exists. Use discovery or triage first.
- The pattern is purely syntactic and already obvious. Use
semgrep-rule-creatordirectly. - The question is exploit-chain composition across multiple findings. Use a composition workflow.
- The goal is remediation verification. Use a remediation-review workflow.
- The seed cannot be bound to a graph node.
Rationalizations to Reject
| Rationalization | Why It Is Wrong | Required Action |
|---|---|---|
| "Nearby code means variant" | Proximity is only a candidate reason | Rank it as a review target |
| "Only exact same names matter" | Variants often share sinks or preconditions, not names | Expand across callers, callees, interfaces, and types |
| "Every candidate is a finding" | This skill outputs candidates for review | Avoid vulnerability claims |
| "Unreachable candidates can be ignored completely" | They may become reachable after refactors | Rank lower or list as deferred |
| "Graph candidates replace semantic pattern work" | Graph structure finds locations, not root-cause semantics | Hand off to variant-analysis, Semgrep, CodeQL, or manual review |
Workflow
Variant Neighborhood Progress:
- [ ] Step 1: Normalize and bind the seed
- [ ] Step 2: Expand graph neighborhoods
- [ ] Step 3: Rank candidates
- [ ] Step 4: Extract variant pattern guidance
- [ ] Step 5: Emit handoff packetStep 1: Normalize And Bind The Seed
Accept finding text, file/line, function name, or output from
trailmark-finding-triage. Bind the seed to a Trailmark node and record the
root cause in plain language.
If the seed has no concrete graph binding, stop before inventing variants.
Show full SKILL.md (164 more words)Show less
Step 2: Expand Neighborhoods
Use the dimensions in references/neighborhood-patterns.md:
- shared callers
- shared callees and sinks
- entrypoint path neighbors
- interface, override, trait, and implementation siblings
- file or module cluster neighbors
- taint or privilege-boundary peers
- type and state-reference neighbors
Bound expansion to avoid candidate floods.
Step 3: Rank Candidates
Rank with references/ranking.md. Prioritize entrypoint-reachable, tainted, boundary-adjacent, high-blast-radius, shared sink, same-interface, and close-distance candidates. Penalize test, mock, generated, vendor, unreachable, and trusted-internal-only candidates.
Step 4: Extract Pattern Guidance
Summarize what should be searched for syntactically and what requires semantic review. Identify whether follow-up belongs in:
variant-analysissemgrep-rule-creatorstatic-analysiswith CodeQL or SARIF-producing tools- manual review
Step 5: Emit Handoff Packet
Use references/output-format.md. Include ranked candidates, inclusion reasons, exclusions, limitations, and the variant-analysis handoff.
Stop Conditions
- No graph binding exists
- Candidate count is too high and the root cause is underspecified
- Trailmark cannot analyze the target language
- The seed is only in test, generated, or vendor code and the user did not say that code is in scope
© trailofbits, CC-BY-SA-4.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 5 other files (references, assets) in plugins/trailmark/skills/trailmark-variant-neighborhood of trailofbits/skills.
- SKILL.md
- agents/openai.yaml
- assets/trail-of-bits-mark.svg
- references/neighborhood-patterns.md
- references/output-format.md
- references/ranking.md
Open the folder on GitHubat commit 442fc9d
Compare with similar skills
Trailmark Variant Neighborhood next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Trailmark Variant Neighborhood this skilltrailofbits/skills | 7.5k | — | ~1.1k | Automated safety check: Notes | CC-BY-SA-4.0 | |
| Semgrepvigolium/piolium | 140 | 1 repos | ~2.4k | Automated safety check: Notes | MIT | |
| Sast SemgrepAgentSecOps/SecOpsAgentKit | 220 | 2 repos | ~2.4k | Automated safety check: Pass | Custom licence | |
| Semgrepwaybarrios/opencode-power-pack | 534 | — | ~2.4k | Automated safety check: Pass | MIT | |
| Semgrepsemgrep/skills | 324 | — | ~2.3k | Automated safety check: Pass | Custom licence | |
| Code Auditzhaoxuya520/reverse-skill | 41k | 2 repos | ~374 | Automated safety check: Warn | MIT |
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Related
Works with
Categories
Questions about Trailmark Variant Neighborhood
What does Trailmark Variant Neighborhood do?
Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common…. Trailmark Variant Neighborhood is an agent skill from trailofbits/skills, published by the product's own GitHub organization. Expands one confirmed or suspected vulnerability into a Trailmark graph neighborhood of variant candidates by finding sibling functions, shared callers and callees, common sensitive sinks, common entrypoint paths, interface implementations, override relationships, type/reference neighbors, and structurally similar nodes.
When should I use Trailmark Variant Neighborhood?
Trailmark Variant Neighborhood fits situations like: tasks that involve Static analysis and SAST.
How do I install Trailmark Variant Neighborhood in Claude Code?
Run `npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a claude-code`. Or copy the skill folder (plugins/trailmark/skills/trailmark-variant-neighborhood in trailofbits/skills) into .claude/skills/trailmark-variant-neighborhood in your project. Claude Code loads it when a task matches its description.
How do I install Trailmark Variant Neighborhood in Codex?
Run `npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a codex`. Or copy the skill folder (plugins/trailmark/skills/trailmark-variant-neighborhood in trailofbits/skills) into .agents/skills/trailmark-variant-neighborhood in your project. Codex loads it when a task matches its description.
Can I use Trailmark Variant Neighborhood in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add trailofbits/skills --skill trailmark-variant-neighborhood -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/trailmark-variant-neighborhood, .gemini/skills/trailmark-variant-neighborhood, .github/skills/trailmark-variant-neighborhood and .opencode/skills/trailmark-variant-neighborhood in your project.
What does Trailmark Variant Neighborhood need to run?
SKILL.md names no scripts, command-line tools or credentials: Trailmark Variant Neighborhood is instructions for the agent only. Its frontmatter pre-approves these tools: Bash, Read, Grep, Glob, Write.
Does Trailmark Variant Neighborhood access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Trailmark Variant Neighborhood safe to install?
Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.
What licence does Trailmark Variant Neighborhood use?
Trailmark Variant Neighborhood is published under the CC-BY-SA-4.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Trailmark Variant Neighborhood use?
About 1.1k tokens (SKILL.md is roughly 4.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.3k tokens, read only when the agent opens those files.
What are the alternatives to Trailmark Variant Neighborhood?
Skills that share tags, products or a category with Trailmark Variant Neighborhood: Semgrep (vigolium/piolium, 140 stars), Sast Semgrep (AgentSecOps/SecOpsAgentKit, 220 stars), Semgrep (waybarrios/opencode-power-pack, 534 stars) and Semgrep (semgrep/skills, 324 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Trailmark Variant Neighborhood?
trailofbits (a GitHub organization, an official publisher) maintains it in trailofbits/skills, which has 7,455 GitHub stars. The repository holds 79 skills in this directory. The repository was last updated on October 9, 2026.
Source: trailofbits/skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.