retellai-sdk-patterns

# Retell AI SDK Patterns ## Overview Production-ready patterns for Retell AI: client singletons, typed agent configurations, call management, and error handling. ## Prerequisites - Completed `retellai-install-auth` - `retell-sdk` installed ## Instructions ### Step 1: Singleton Client ```typescript import Retell from 'retell-sdk'; let _retell: Retell | null = null; export function getRetellClient(): Retell { if (!_retell) { _retell = new Retell({ apiKey: process.env.RETELL_API_KEY! }); } return _retell; } ``` ### Step 2: Typed Agent Configuration ```typescript interface AgentConfig { name: string; voiceId: string; prompt: string; functions?: FunctionConfig[]; maxCallDurationMs?: number; endCallAfterSilenceMs?: number; } async function createAgent(config: AgentConfig) { const retell = getRetellClient(); const llm = await retell.llm.create({ model: 'gpt-4o', general_prompt: config.prompt, functions: config.functions, }); const agent = await retell.agent.create({ response_engine: { type: 'retell-llm', llm_id: llm.llm_id }, voice_id: config.voiceId, agent_name: config.name, max_call_duration_ms: config.maxCallDurationMs || 300000, end_call_after_silence_ms: config.endCallAfterSilenceMs || 10000, }); return { agentId: agent.agent_id, llmId: llm.llm_id }; } ``` ### Step 3: Call Manager with Retry ```typescript async function makeCallWithRetry( fromNumber: string, toNumber: string, agentId: string, maxRet...