retellai-common-errors

# Retell AI Common Errors ## Overview Quick reference for the top Retell AI errors and their solutions. ## Prerequisites - `retell-sdk` installed - API key configured ## Instructions ### Error 1: 401 Unauthorized ``` RetellError: 401 — Invalid API key ``` **Fix:** Verify API key in Retell Dashboard. Ensure `RETELL_API_KEY` starts with `key_`. ### Error 2: Call Fails Immediately ``` RetellError: 400 — Invalid phone number format ``` **Fix:** Use E.164 format: `+14155551234`. Both `from_number` and `to_number` must be valid. ### Error 3: Agent Not Responding ``` Call connected but agent says nothing ``` **Fix:** Check LLM configuration: ```typescript const llm = await retell.llm.retrieve(agent.response_engine.llm_id); console.log(`Model: ${llm.model}`); console.log(`Prompt length: ${llm.general_prompt.length} chars`); // Ensure general_prompt is not empty and gives clear instructions ``` ### Error 4: Function Call Timeout ``` Function call to https://your-api.com/endpoint timed out ``` **Fix:** Your function endpoint must respond within 5 seconds. Offload heavy work: ```typescript app.post('/functions/lookup', async (req, res) => { // Respond immediately with acknowledgment const result = await quickLookup(req.body.args); res.json({ result: `Found: ${result.name}` }); // Do NOT run async work before responding }); ``` ### Error 5: Webhook Not Receiving Events ``` No webhook events received after call ``` **Fix:** Set `webhook_url` on the agent, not just in Dashb...