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,
timeout: 120_000,
});
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;
}
}
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++;
. = .();
}
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) {
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,
});
const message = await client.messages.create(params, {
timeout: 120_000,
});
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.
