# Troubleshoot by failure stage

> Find the responsible boundary before changing prompts, providers, or infrastructure.

## Identify the failing stage

Record the workspace, agent ID, run ID when available, time, call direction, channel, and exact error. Remove secrets before sharing logs.

| Symptom | Check first | Reference |
| --- | --- | --- |
| API returns 401 | API key, header, and owning organization | [Authentication](/api-reference/authentication) |
| API returns 402 | Feature entitlement, workflow limit, or inference balance named in the error | [Billing](/operations/billing) |
| Draft will not publish | Validation errors, complete graph, and conflicting triggers | [Versions](/voice-agent/versions) |
| Call starts without audio | Microphone, model validation, WebRTC/ICE, and TURN | [Setup troubleshooting](/getting-started/troubleshooting) |
| Inbound number reaches the wrong agent | Number mapping, provider webhook, and published trigger | [Inbound routing](/integrations/telephony/inbound) |
| Outbound initiation succeeds but no conversation occurs | Carrier events, destination restrictions, caller ID, and media | [Telephony](/integrations/telephony/overview) |
| Tool is never called | Node attachment, prompt instruction, schema, and required values | [Tools](/voice-agent/tools/introduction) |
| Knowledge produces no answer | Document processing state, embedding configuration, and query relevance | [Knowledge base](/voice-agent/knowledge-base) |
| Webhook did not update your system | Completed run, template values, credentials, receiver logs, and retry policy | [Webhook payloads](/developer/webhooks) |
| Production differs from an editor test | Published definition, runtime context, and model overrides | [Testing](/voice-agent/testing) |

## Change one responsible part

A healthy homepage does not establish that model calls, media, storage, or a queue worker work. Reproduce the smallest failing operation, inspect its evidence, fix that boundary, and run the same check again.

## Escalate with useful evidence

Provide the exact failing step, expected and actual result, timestamp, relevant IDs, and redacted error text. Include whether text chat, Web Call, telephony, and downstream delivery passed independently. For self-hosting, include the deployed image or commit and the affected service logs.