Anthropic Reliability Patterns Skill

Anthropic Reliability Patterns

Overview

Build fault-tolerant Claude integrations with built-in SDK retries, model fallback chains (Sonnet → Haiku), circuit breakers to avoid hammering a failing API, graceful degradation with cached/static responses, and per-request timeout configuration.

Built-In SDK Retries

The SDK retries 429 (rate limit) and 529 (overloaded) automatically:

const client = new Anthropic({
  maxRetries: 3, // default: 2
  timeout: 120_000, // 2 minutes
});

Model Fallback Chain

const FALLBACK_CHAIN = ['claude-sonnet-4-20250514', 'claude-haiku-4-5-20251001'];

async function callWithFallback(params: Anthropic.MessageCreateParams) {
  for (const model of FALLBACK_CHAIN) {
    try {
      return await client.messages.create({ ...params, model });
    } catch (err) {
      if (err instanceof Anthropic.APIError && err.status >= 500) {
        console.warn(`${model} failed (${err.status}), trying next...`);
        continue;
      }
      throw err; // Don't retry client errors (4xx)
    }
  }
  throw new Error('All models failed');
}

Circuit Breaker

class ClaudeCircuitBreaker {
  private failures = 0;
  private lastFailure = 0;
  private readonly threshold = 5;
  private readonly resetMs = 60_000;

  async call(params: Anthropic.MessageCreateParams) {
    if (this.failures >= this.threshold && Date.now() - this.lastFailure < this.resetMs) {
      throw new Error('Circuit open — Claude API unavailable');
    }

    try {
      const result = await client.messages.create(params);
      this.failures = 0;
      return result;
    } catch (err) {
      if (err instanceof Anthropic.APIError && err.status >= 500) {
        this.failures++;
        this.lastFailure = Date.now();
      }
      throw err;
    }
  }
}

Graceful Degradation

async function getResponse(userInput: string): Promise<string> {
  try {
    const message = await client.messages.create({
      model: 'claude-sonnet-4-20250514',
      max_tokens: 1024,
      messages: [{ role: 'user', content: userInput }],
    });
    return message.content[0].text;
  } catch (err) {
    // Return cached/static response instead of failing
    console.error('Claude unavailable, using fallback');
    return "I'm temporarily unable to process your request. Please try again shortly.";
  }
}

Timeout Handling

const client = new Anthropic({
  timeout: 30_000, // 30s for most requests
});

// Override per-request for long-running tasks
const message = await client.messages.create(params, {
  timeout: 120_000, // 2 minutes for complex prompts
});

Output

SDK configured with appropriate maxRetries and timeout
Model fallback chain automatically trying cheaper models on failure
Circuit breaker preventing cascading failures during outages
Graceful degradation returning static responses when Claude is unavailable

Error Handling

| Error | Cause | Solution | |-------|-------|----------| | API Error | Check error type and status code | See clade-common-errors |

Examples

See Built-In SDK Retries, Model Fallback Chain, Circuit Breaker class, Graceful Degradation handler, and Timeout Handling above.

Resources

Next Steps

See clade-policy-guardrails for content safety patterns.

Prerequisites

Completed clade-install-auth
Production Claude integration requiring high availability
Understanding of fault tolerance patterns (retries, circuit breakers)

Instructions

Step 1: Review the patterns below

Each section contains production-ready code examples. Copy and adapt them to your use case.

Step 2: Apply to your codebase

Integrate the patterns that match your requirements. Test each change individually.

Step 3: Verify

Run your test suite to confirm the integration works correctly.

Agent Skills: Anthropic Reliability Patterns

Install this agent skill to your local

Skill Files