# Jeremylongshore Claude Code Plugins Plus Skills Retellai Common Errors

> Retell AI Common Errors

- Skill: `tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-retellai-com` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-retellai-com`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-retellai-com/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-retellai-com

---


# 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 Dashboard settings:
```typescript
await retell.agent.update(agentId, {
  webhook_url: 'https://your-app.com/webhooks/retell',
});
```

### Error 6: Voice Quality Issues
```
Agent voice sounds robotic/choppy
```
**Fix:** Check network latency to Retell servers. Use a voice optimized for your use case. Try different voice IDs.

## Output
- Error identified and root cause found
- Fix applied and verified
- Call successfully completed

## Error Handling
| HTTP Code | Meaning | Retryable |
|-----------|---------|-----------|
| 400 | Bad request | No — fix params |
| 401 | Invalid API key | No — fix key |
| 404 | Agent/call not found | No — fix ID |
| 429 | Rate limited | Yes — backoff |
| 500+ | Server error | Yes — retry |

## Resources
- [Retell AI Documentation](https://docs.retellai.com)
- [retell-sdk npm](https://www.npmjs.com/package/retell-sdk)

## Next Steps
For debugging, see `retellai-debug-bundle`.

---
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<!-- tomevault:4.0:skill_md:2026-04-11 -->