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error-patterns

Testing & Quality
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Provides error classification, recovery, and graceful-degradation patterns. Use when implementing error handling or debugging resilience failures in any skill.

QUICK START

How to use this skill

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  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
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Source SKILL.md: https://github.com/athola/claude-night-market/blob/HEAD/plugins/leyline/skills/error-patterns/SKILL.md

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Table of Contents

Error Patterns

Overview

Standardized error handling patterns for consistent, production-grade behavior across plugins. Provides error classification, recovery strategies, and debugging workflows.

When To Use

  • Building resilient integrations
  • Need consistent error handling
  • Want graceful degradation
  • Debugging production issues

When NOT To Use

  • Project doesn't use the leyline infrastructure patterns
  • Simple scripts without service architecture needs

Error Classification

By Severity

LevelActionExample
CriticalHalt, alertAuth failure, service down
ErrorRetry or secondary strategyRate limit, timeout
WarningLog, continuePartial results, deprecation
InfoLog onlyNon-blocking issues

By Recoverability

class ErrorCategory(Enum):
    TRANSIENT = "transient"      # Retry likely to succeed
    PERMANENT = "permanent"       # Retry won't help
    CONFIGURATION = "config"      # User action needed
    RESOURCE = "resource"         # Quota/limit issue

Verification: Run the command with --help flag to verify availability.

Quick Start

Standard Error Handler

from leyline.error_patterns import handle_error, ErrorCategory

try:
    result = service.execute(prompt)
except RateLimitError as e:
    return handle_error(e, ErrorCategory.RESOURCE, {
        "retry_after": e.retry_after,
        "service": "gemini"
    })
except AuthError as e:
    return handle_error(e, ErrorCategory.CONFIGURATION, {
        "action": "Run 'gemini auth login'"
    })

Verification: Run the command with --help flag to verify availability.

Error Result

@dataclass
class ErrorResult:
    category: ErrorCategory
    message: str
    recoverable: bool
    suggested_action: str
    metadata: dict

Verification: Run the command with --help flag to verify availability.

Common Patterns

Authentication Errors (401/403)

  • Verify credentials exist
  • Check token expiration
  • Validate permissions/scopes
  • Suggest re-authentication

Rate Limit Errors (429)

  • Extract retry-after header
  • Log for quota tracking
  • Implement backoff
  • Consider alternative service

Timeout Errors

  • Increase timeout for retries
  • Break into smaller requests
  • Use async patterns
  • Consider different model

Context Too Large (400)

  • Estimate tokens before request
  • Split into multiple requests
  • Reduce input content
  • Use larger context model

Integration Pattern

# In your skill's frontmatter
dependencies: [leyline:error-patterns]

Verification: Run the command with --help flag to verify availability.

Detailed Resources

  • Classification: See modules/classification.md for error taxonomy
  • Recovery: See modules/recovery-strategies.md for handling patterns
  • Agent Damage Control: See modules/agent-damage-control.md for multi-agent error recovery and escalation

Exit Criteria

  • Error classified correctly
  • Appropriate recovery attempted
  • User-actionable message provided
  • Error logged for debugging