Agent skill · Code Review & Quality

doublecheck

Three-layer verification pipeline for AI output. Extracts verifiable claims, finds supporting or contradicting sources via web search, runs adversarial review for hallucination patterns, and produces a structured verification report with source links for human review.

GitHub68,948★ · +463/wk · 2 repos on radarProfile →
copilotMIT
Install
npx skills add github/awesome-copilot --skill doublecheck --agent copilot

Same command for any agent — swap --agent for claude-code, codex, cursor.

Facts
Files in the skill folder: 2
SKILL.md size: 16 KB
Bundled scripts: none
Path: skills/doublecheck/SKILL.md
Open the folder on GitHub →
Where it comes from
Stars: 37,432 · +281 this week
Language: Python

Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.

From the SKILL.md

# Doublecheck Run a three-layer verification pipeline on AI-generated output. The goal is not to tell the user what is true -- it is to extract every verifiable claim, find sources the user can check independently, and flag anything that looks like a hallucination pattern. ## Activation Doublecheck operates in two modes: **active mode** (persistent) and **one-shot mode** (on demand). ### Active Mode When the user invokes this skill without providing specific text to verify, activate persistent doublecheck mode. Respond with: > **Doublecheck is now active.** I'll verify factual claims in my responses before presenting them. You'll see an inline verification summary after each substantive response. Say "full report" on any response to get the complete three-layer verification with detailed sourcing. Turn it off anytime by saying "turn off doublecheck." Then follow ALL of the rules below for the remainder of the conversation: **Rule: Classify every response before sending it.** Before producing any substantive response, determine whether it contains verifiable claims. Classify the response: | Response type | Contains verifiable claims? | Action | |--------------|----------------------

What's inside
Steps it walks through
  1. Activation
  2. Active Mode
  3. One-Shot Mode
  4. Deactivation
  5. Layer 1: Self-Audit
  6. Step 1: Extract Claims
  7. Step 2: Check Internal Consistency
  8. Step 3: Initial Confidence Assessment
  9. Layer 2: Source Verification
  10. Search Strategy
  11. What Counts as a Source
  12. Handling Citations Specifically
  13. Layer 3: Adversarial Review
  14. Hallucination Pattern Checklist
Ships with 1 file
  • assets/verification-report-template.md
More from awesome-copilot
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About this skill
What does the doublecheck skill do?

Three-layer verification pipeline for AI output. Extracts verifiable claims, finds supporting or contradicting sources via web search, runs adversarial review for hallucination patterns, and produces a structured verification report with source links for human review.

How do I install it?

Run `npx skills add github/awesome-copilot --skill doublecheck --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.

Where does this skill come from?

From github/awesome-copilot, a repository with 37,432 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.

Is a popular skill a good skill?

Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.

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