How It Works

Slopcannon analyzes pull request diffs to detect patterns commonly associated with AI-generated code.

Analysis Pipeline

PR Opened/Updated → Webhook → Diff Fetched → Patterns Detected → Score Calculated → Results Stored

1. Webhook Trigger

When a pull request is opened, synchronized, or reopened, GitHub sends a webhook to Slopcannon. The system then:

• Verifies the webhook signature
• Checks if the repository is enabled
• Checks draft PR settings
• Queues the analysis job

2. Diff Analysis

The worker fetches the PR diff from GitHub and parses it to identify:

• Added lines (new code)
• Modified files
• File types and classifications

3. Pattern Detection

Each file is classified and analyzed for slop patterns:

File Classification

Detection Patterns

Mystery Fallbacks (2 points each)

// Empty catch blocks
try { ... } catch (e) { }
 
// Generic error swallowing
catch (error) { console.log(error) }

Silent Catches (3 points each)

// Ignored promise rejections
promise.catch(() => {})
 
// Swallowed exceptions
try { risky() } catch { /* nothing */ }

Style Drift (1 point each)

• Inconsistent naming conventions
• Mixed formatting patterns
• Orphaned TODO/FIXME comments

Complexity Issues (variable points)

• Deeply nested conditionals (>4 levels)
• Excessive function length
• High cyclomatic complexity

Scoring System

The slop score is additive - each finding adds to the total. There is no maximum score.

For detailed explanations of each pattern and why it matters, see Slop Scoring.

Ghost Mode

By default, Slopcannon operates in ghost mode:

• ✅ Analyzes all PRs
• ✅ Stores results in the dashboard
• ❌ Does not post GitHub comments
• ❌ Does not create check runs

This allows teams to evaluate the tool before enabling visible feedback.

Priority Queue

Analysis jobs are prioritized:

1. Live PRs (from webhooks) - Immediate processing
2. Open PRs (initial import) - High priority
3. Recent closed (last 7 days) - Medium priority
4. Historical (7-90 days) - Low priority

This ensures new PRs get analyzed quickly while historical imports happen in the background.