Setting Up Your API Key
Why You Need an API Key
Flow Builder at the Flow Builder uses a Bring Your Own Key (BYOK) model. You provide your own LLM API key from OpenAI, Anthropic, or OpenRouter, and the platform routes all AI calls through your account. This means you control costs, rate limits, and model access directly.
An API key is required before you can test or deploy any flow. Without one, Conversation and Extraction nodes have no LLM to call.
Supported Providers
| Provider | Key Format | Models Available |
|---|---|---|
| OpenAI | sk-... | GPT-4o, GPT-4o-mini, GPT-4, etc. |
| Anthropic | sk-ant-... | Claude Sonnet, Claude Haiku, etc. |
| OpenRouter | sk-or-... | Access to 100+ models from multiple providers |
Adding Your API Key
- Open your flow at the Flow Builder.
- Click the Settings icon in the top toolbar (gear icon).
- In the settings panel, locate the API Key section.
- Select your provider from the dropdown (OpenAI, Anthropic, or OpenRouter).
- Paste your API key into the key field.
- Click Save.
The key is stored securely and used for all LLM calls within that flow.
Choosing a Default Model
After entering your API key, select a default model for the flow. This is the model used by all Conversation and Extraction nodes unless a specific node overrides it.
For voice flows where latency matters, faster models like gpt-4o-mini or claude-haiku are recommended. For complex reasoning tasks, use gpt-4o or claude-sonnet.
Individual nodes can override the default model in their advanced settings. This lets you use a cheaper model for simple interactions and a more capable model for critical decision points.
OpenRouter: Multi-Provider Access
If you want access to models from multiple providers through a single key, use OpenRouter. It acts as a proxy, giving you access to OpenAI, Anthropic, Meta, Mistral, and many other providers under one API key. This is useful if you want to experiment with different models across nodes without managing multiple keys.
Troubleshooting
| Issue | Solution |
|---|---|
| Test returns "No API key configured" | Open Settings and verify your key is saved |
| 401 Unauthorized errors | Check that your key is valid and has not expired |
| Model not available | Ensure your API plan includes access to the selected model |
| Rate limit errors | Check your provider's usage dashboard for quota limits |
Important: Your API key is never shared with other users or flows. Each flow stores its own key configuration independently.