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Overview

Flow Builder uses a Bring Your Own Key (BYOK) model. You provide your own LLM API key, and the platform routes all AI calls through your account. This gives you control over costs, rate limits, and model access.
An API key is required before you can test or deploy any flow. Without one, Conversation and Extraction nodes have no LLM to call.

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Supported Providers

ProviderKey FormatModels
OpenAIsk-...GPT-4o, GPT-4o-mini, GPT-4, etc.
Anthropicsk-ant-...Claude Sonnet, Claude Haiku, etc.
OpenRoutersk-or-...100+ models from multiple providers

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Adding Your Key

1

Open Flow Settings

Click the Settings icon (gear) in the top toolbar.
2

Select Provider

Choose OpenAI, Anthropic, or OpenRouter from the dropdown.
3

Paste Your Key

Enter your API key and click Save.
4

Choose Default Model

Select the default model for the flow. Individual nodes can override this in their advanced settings.

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Model Recommendations

  • Voice flows (latency matters): gpt-4o-mini or claude-haiku
  • Complex reasoning: gpt-4o or claude-sonnet
  • Multi-provider access: Use OpenRouter for a single key across all providers

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Troubleshooting

IssueSolution
”No API key configured”Open Settings and verify your key is saved
401 UnauthorizedCheck that your key is valid and hasn’t expired
Model not availableEnsure your API plan includes the selected model
Rate limit errorsCheck your provider’s usage dashboard
Your API key is never shared with other users or flows. Each flow stores its own key independently.

Testing

Test your flow with your key

Engine & Streaming

How models are resolved

Voice Connection

Deploy to voice