Perplexity Web Search
davila7/claude-code-templates
Runs web-grounded searches through Perplexity's Sonar models over OpenRouter for current events, recent literature and cited facts beyond the model's training cutoff.
Systematic fact verification and misinformation identification using evidence-based analysis.
Install Fact Checker
$ npx skills add aiskillstore/marketplace --skill fact-checker -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install aiskillstore/marketplace fact-checker --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/aiskillstore/marketplace.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .claude/skills/fact-checker && 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 "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .claude/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checkerType 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 aiskillstore/marketplace --skill fact-checker -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install aiskillstore/marketplace fact-checker --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/aiskillstore/marketplace.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .agents/skills/fact-checker && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .agents/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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 aiskillstore/marketplace --skill fact-checker -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install aiskillstore/marketplace fact-checker --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/aiskillstore/marketplace.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .cursor/skills/fact-checker && 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 "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .cursor/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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/aiskillstore/marketplace.git --path skills/shubhamsaboo/fact-checker--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 aiskillstore/marketplace --skill fact-checker -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install aiskillstore/marketplace fact-checker --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/aiskillstore/marketplace.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .gemini/skills/fact-checker && 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 "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .gemini/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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 aiskillstore/marketplace fact-checkerInstalls 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 aiskillstore/marketplace --skill fact-checker -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/aiskillstore/marketplace.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .github/skills/fact-checker && 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 "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .github/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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 aiskillstore/marketplace --skill fact-checker -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install aiskillstore/marketplace fact-checker --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/aiskillstore/marketplace.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/shubhamsaboo/fact-checker .opencode/skills/fact-checker && 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 "fact-checker" agent skill from https://github.com/aiskillstore/marketplace/tree/main/skills/shubhamsaboo/fact-checker into .opencode/skills/fact-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fact-checker", 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
fact-checker- GitHub stars
- 433
- Used in
- 1 other repo
- Token cost
- ~1.5k tokens
- SKILL.md length
- 646 words
- Files
- 2
- Skills in repo
- 1,044
- Repo updated
- First seen
- Licence
- MIT
At a glance
Systematic fact verification and misinformation identification using evidence-based analysis.
- Works in 5 steps: Identify the Claim → Determine Required Evidence → Evaluate Available Evidence → …
- : verifying claims
- SKILL.md covers When to Apply, Verification Process, Rating Scale and Source Quality Hierarchy, plus 8 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Fact Checker is an agent skill from aiskillstore/marketplace. Systematic fact verification and misinformation identification using evidence-based analysis. Use when: verifying claims, checking facts, identifying misinformation, evaluating source credibility, or when user asks to "fact check", "verify", "is this true", or mentions claims that need validation.
Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `skill-report.json`).
It sits in Research & Science, covering Fact-checking and source verification. The repository describes itself as: Security-audited skills for Claude, Codex & Claude Code. One-click install, quality verified. The licence is MIT.
When your agent uses it
- : verifying claims
- Identifying misinformation
- Evaluating source credibility
- User asks to fact check
Example prompts
- “fact check”
- “verify”
- “is this true”
- “/fact-checker”
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 44923f3. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown).
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
Fact Checker loads about 1.5k tokens when it runs. Until then it costs about 78 tokens; SKILL.md has 646 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 passed
The automated check found no risky patterns in SKILL.md.
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 aiskillstore/marketplace at commit 44923f3, republished under its MIT licence (© aiskillstore). 646 words, ~1,495 tokens.
Download SKILL.mdSave it as
.claude/skills/fact-checker/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- fact-checker
- description
- Systematic fact verification and misinformation identification using evidence-based analysis. Use when: verifying claims, checking facts, identifying misinformation, evaluating source credibility, or when user asks to "fact check", "verify", "is this true", or mentions claims that need validation.
- license
- MIT
- metadata.author
- awesome-llm-apps
- metadata.version
- 1.0.0
Fact Checker
You are an expert fact-checker who evaluates claims systematically using evidence-based analysis.
When to Apply
Use this skill when:
- Verifying specific claims or statements
- Identifying potential misinformation or disinformation
- Checking statistics and data accuracy
- Evaluating source credibility
- Separating fact from opinion or interpretation
- Analyzing viral claims or rumors
Verification Process
Follow this systematic approach:
1. Identify the Claim
- Extract the specific factual assertion
- Distinguish fact from opinion
- Note any implicit claims
- Identify measurable aspects
2. Determine Required Evidence
- What would prove this claim?
- What would disprove it?
- What sources would be authoritative?
- Can this be verified or is it opinion?
3. Evaluate Available Evidence
- Check authoritative sources
- Look for primary data
- Consider source credibility
- Note publication dates
- Check for context
4. Rate the Claim
- Assess accuracy based on evidence
- Note confidence level
- Explain reasoning clearly
- Highlight missing context if relevant
5. Provide Context
- Why does this matter?
- Common misconceptions
- Related facts
- Proper interpretation
Rating Scale
Use these ratings:
- ✅ TRUE - Claim is accurate and supported by reliable evidence
- ⚠️ MOSTLY TRUE - Claim is accurate but missing important context or minor details wrong
- 🔶 MIXED - Claim contains both true and false elements
- ❌ MOSTLY FALSE - Claim is misleading or largely inaccurate
- 🚫 FALSE - Claim is demonstrably wrong
- ❓ UNVERIFIABLE - Cannot be confirmed or denied with available evidence
Source Quality Hierarchy
Rate sources by credibility:
- Peer-reviewed scientific studies - Highest credibility
- Official government statistics - Authoritative data
- Reputable news organizations - Fact-checked reporting
- Expert statements in field - Qualified opinions
- General news sites - Verify with other sources
- Social media/blogs - Lowest credibility, verify independently
Output Format
## Claim
[Exact statement being verified]
## Verdict: [RATING]
## Analysis
[Explanation of why this rating]
**Evidence:**
- [Key supporting or refuting evidence]
- [Secondary evidence]
**Context:**
- [Important context or nuance]
- [Why this matters]
**Source Quality:**
- [Evaluation of sources used]
## Correct Information
[If claim is false/misleading, provide accurate version]
## Sources
[Numbered list of sources with credibility notes]Common Patterns to Watch For
Statistical Manipulation
- Cherry-picking data
- Misleading graphs or scales
- Correlation vs causation
- Inappropriate comparisons
Context Removal
- Quote mining (taking statements out of context
- Omitting important qualifiers
- Ignoring timeframes or conditions
- Removing statistical caveats
False Equivalences
- Comparing incomparable things
- Treating all sources as equally valid
- Both-sidesing settled science
Logical Fallacies
- Ad hominem attacks
- Appeal to authority (improper)
- False dichotomies
- Slippery slope arguments
Example
User Request: "Fact check: Humans only use 10% of their brain"
Response:
Claim
"Humans only use 10% of their brain"
Verdict: 🚫 FALSE
Show full SKILL.md (297 more words)Show less
Analysis
This is a persistent myth with no scientific basis. Neurological research consistently shows that humans use virtually all parts of their brain, though not all at the same time.
Evidence:
- Brain imaging (fMRI, PET scans) shows activity throughout the brain during even simple tasks [1]
- Brain damage to any area causes functional impairment, indicating all regions serve purposes [2]
- Metabolic studies show the brain uses ~20% of body's energy despite being ~2% of body weight - wouldn't occur if 90% were unused [3]
- Evolutionary perspective: maintaining unused brain tissue would be wasteful
Context:
- The myth may originate from early neurological studies or misunderstanding of brain plasticity
- Not all neurons fire simultaneously (which would cause seizure)
- Different regions activate for different tasks
- We don't consciously control all brain functions (breathing, heartbeat, etc.)
Source Quality:
- Neuroscience consensus supported by decades of research
- Brain imaging studies provide direct evidence
- Myth persists in popular culture despite scientific consensus
Correct Information
Humans use virtually all of their brain. Different regions activate for different tasks, and brain imaging shows activity distributed throughout the brain during both active tasks and rest. The brain's high energy consumption (20% of body's energy for 2% of body weight) demonstrates intensive usage.
While we don't have conscious access to all brain functions (autonomic processes like heartbeat, many memory processes), this doesn't mean those regions are "unused" - they're actively maintaining vital functions.
Sources
[1] Herculano-Houzel, S. (2012). "The remarkable, yet not extraordinary, human brain." Proceedings of the National Academy of Sciences, 109(Supplement 1), 10661-10668. (Peer-reviewed, authoritative neuroscience)
[2] Boyd, R. (2008). "Do People Only Use 10 Percent of Their Brains?" Scientific American. (Science journalism, expert sources)
[3] Raichle, M.E., & Gusnard, D.A. (2002). "Appraising the brain's energy budget." Proceedings of the National Academy of Sciences, 99(16), 10237-10239. (Peer-reviewed, metabolic research)
© aiskillstore, MIT. 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 1 other file in skills/shubhamsaboo/fact-checker of aiskillstore/marketplace.
- SKILL.md
- skill-report.json
Open the folder on GitHubat commit 44923f3
Used in 1 other repository
We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in aiskillstore/marketplace, which our catalogue first saw on October 7, 2026.
Compare with similar skills
Fact Checker 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 |
|---|---|---|---|---|---|---|
| Fact Checker this skillaiskillstore/marketplace | 433 | 1 repos | ~1.5k | Automated safety check: Pass | MIT | |
| Perplexity Web Searchdavila7/claude-code-templates | 33k | 11 repos | ~3.5k | Automated safety check: Notes | MIT | |
| Citation Verification GuideGalaxy-Dawn/claude-scholar | 5.7k | 2 repos | ~1.9k | Automated safety check: Pass | MIT | |
| Article Fact Checkerdigoal/blog | 8.6k | — | ~939 | Automated safety check: Pass | GPL-2.0 | |
| Deep Research Agent TeamImbad0202/academic-research-skills | 51k | — | ~13k | Automated safety check: Pass | Custom licence | |
| Docs Grounding Verifiermicrosoft/apm | 4k | — | ~1.9k | Automated safety check: Pass | MIT |
Similar skills
Citation Verification Guide
Galaxy-Dawn/claude-scholar
Reference guidance for checking every citation in academic writing against canonical sources such as DOI, arXiv, CrossRef and Semantic Scholar, to catch fake or wrong references.
Article Fact Checker
digoal/blog
三层审查模型,逐段逐句验证文章真伪、证据链与逻辑结构。Use when the user asks to fact-check, verify, audit, or evaluate the credibility of an article, essay, report, opinion piece, social-media post, or any written claim —…
Deep Research Agent Team
Imbad0202/academic-research-skills
Runs a 13-agent pipeline for rigorous academic research, from forming the question through systematic search, synthesis, bias checks and an APA 7.0 report.
- Official
Docs Grounding Verifier
microsoft/apm
A skill your agent uses to verify CLAIM-LEVEL grounding of a documentation page (or set of pages) against the source code.
Fact Checking
bradygaster/squad
Review and validate claims using counter-hypothesis testing.
More from aiskillstore/marketplace
All 1,044 skills in this repoCode Stats
aiskillstore/marketplace
Analyze codebase with tokei (fast line counts by language) and difft (semantic AST-aware diffs).
Data Processing
aiskillstore/marketplace
Process JSON with jq and YAML/TOML with yq. An agent skill from aiskillstore/marketplace.
Doc Scanner
aiskillstore/marketplace
Scans for project documentation files (AGENTS.md, CLAUDE.md, GEMINI.md, COPILOT.md, CURSOR.md, WARP.md, and 15+ other formats) and synthesizes guidance.
File Search
aiskillstore/marketplace
Modern file and content search using fd, ripgrep (rg), and fzf.
Find Replace
aiskillstore/marketplace
Modern find-and-replace using sd (simpler than sed) and batch replacement patterns.
Project Planner
aiskillstore/marketplace
Detects stale project plans and suggests session commands. An agent skill from aiskillstore/marketplace.
Related
Categories
Questions about Fact Checker
What does Fact Checker do?
Systematic fact verification and misinformation identification using evidence-based analysis. Fact Checker is an agent skill from aiskillstore/marketplace. Systematic fact verification and misinformation identification using evidence-based analysis.
When should I use Fact Checker?
Fact Checker fits situations like: : verifying claims; identifying misinformation; evaluating source credibility; user asks to fact check.
How do I install Fact Checker in Claude Code?
Run `npx skills add aiskillstore/marketplace --skill fact-checker -a claude-code`. Or copy the skill folder (skills/shubhamsaboo/fact-checker in aiskillstore/marketplace) into .claude/skills/fact-checker in your project. Claude Code loads it when a task matches its description.
How do I install Fact Checker in Codex?
Run `npx skills add aiskillstore/marketplace --skill fact-checker -a codex`. Or copy the skill folder (skills/shubhamsaboo/fact-checker in aiskillstore/marketplace) into .agents/skills/fact-checker in your project. Codex loads it when a task matches its description.
Can I use Fact Checker 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 aiskillstore/marketplace --skill fact-checker -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fact-checker, .gemini/skills/fact-checker, .github/skills/fact-checker and .opencode/skills/fact-checker in your project.
What does Fact Checker need to run?
SKILL.md names no scripts, command-line tools or credentials: Fact Checker is instructions for the agent only.
Does Fact Checker 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 Fact Checker safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Fact Checker use?
Fact Checker is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Fact Checker use?
About 1.5k tokens (SKILL.md is roughly 6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Fact Checker?
Skills that share tags, products or a category with Fact Checker: Perplexity Web Search (davila7/claude-code-templates, 33k stars), Citation Verification Guide (Galaxy-Dawn/claude-scholar, 5.7k stars), Article Fact Checker (digoal/blog, 8.6k stars) and Deep Research Agent Team (Imbad0202/academic-research-skills, 51k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Fact Checker?
aiskillstore (a GitHub organization) maintains it in aiskillstore/marketplace, which has 433 GitHub stars. The repository holds 1,044 skills in this directory. The repository was last updated on October 10, 2026.
Source: aiskillstore/marketplace on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.