{
  "instruction": "Provide fallback responses when external dependencies fail or time out",
  "relevant_when": "Agent writes code that calls external APIs, databases, or third-party services and returns data to users",
  "context": "Every timeout needs a fallback. When a dependency fails, the code should return something useful instead of crashing or returning a raw error. Fallback strategies include: serving stale/cached data, returning a safe default value, returning a partial response with available data, or disabling a non-critical feature. The choice depends on the data: slowly-changing data can use a cache, data with sensible defaults should return the default, and aggregation endpoints should return whatever data sources are available.",
  "sources": [
    {
      "type": "file",
      "filename": "skills/graceful-degradation/SKILL.md",
      "tile": "tessl-labs/graceful-degradation@0.2.0"
    }
  ],
  "checklist": [
    {
      "name": "catch-returns-fallback",
      "rule": "When an external call fails, the catch block returns a meaningful fallback value (cached data, default value, null with a flag, or partial response) instead of re-throwing or returning a raw error to the user",
      "relevant_when": "Agent writes try/catch blocks around external service calls"
    },
    {
      "name": "failure-logged-with-context",
      "rule": "Caught dependency failures are logged with structured context including the dependency name, the error, and what fallback was used",
      "relevant_when": "Agent writes error handling for external service calls"
    },
    {
      "name": "stale-data-flagged",
      "rule": "When serving cached or stale data as a fallback, the response includes a flag or metadata indicating the data may be out of date (e.g., stale: true, a warning field, or cache age)",
      "relevant_when": "Agent implements cache-based fallbacks for external service data"
    }
  ]
}