### Answer To configure Retell AI credentials in N8N, you'll need your API key from Retell AI [(1) ]() . First, create or retrieve your API key from the Retell AI dashboard: 1. Navigate to System "Settings" and access the "API Keys" section 2. Click the "Add" button to create a new API key 3. Give your key a descriptive name to identify its purpose 4. Copy the generated API key (keep it secure and never share it publicly) Then in N8N, you'll typically: - Add a new credential for Retell AI - Paste your API key into the authentication field - Save the credential If you're setting up webhooks between Retell AI and N8N, you can also designate a specific API key as your webhook key by clicking "Set as Webhook Key" in the Retell AI dashboard . Only one key can be set as the webhook key at a time . For webhook integration, you'll need to configure your N8N webhook URL in Retell AI either at the account level (in the dashboard's webhooks tab) or at the agent level when creating an agent [(2) ]() .

​ To learn more, see the sources I considered: [[1] Manage API Keys](https://docs.retellai.com/accounts/manage-api-keys) [[2] Webhook Overview](https://docs.retellai.com/features/webhook-overview) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

Thanks for the follow-up, @Alexander. I'll get back to you soon.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer The error indicates that the authorization header format is incorrect. When authenticating with Retell AI's API, the format must be "Bearer YOUR_API_KEY" [(1) ]() [(2) ]() [(3) ]() [(4) ]() [(5) ]() . In N8N, verify: 1. The credential field is configured to use the Bearer token authentication scheme 2. The API key is entered without any prefix - N8N should automatically add "Bearer " before your key 3. There are no extra spaces or characters in the API key The correct authorization header format is:

Authorization: Bearer YOUR_API_KEY

. If you're still experiencing issues: - Double-check that you copied the complete API key from the Retell AI dashboard [(6) ]() - Ensure the API key hasn't been deleted in the Retell AI "API Keys" section - Try creating a new API key and updating your N8N credentials - Verify that N8N is set to use "Bearer" (uppercase "B") as the authentication scheme [(7) ]()

### Answer I don't have specific N8N configuration documentation in the available sources, but I can guide you through the Retell AI side and general authentication principles. Step 1: Get Your Retell AI API Key 1. Log into your Retell AI dashboard 2. Look for "Settings" or "API Keys" section [(1) ]() 3. Click to create a new API key 4. Copy the entire key (it will look like a long string of random characters) 5. Save it somewhere safe - you'll only see it once Step 2: Understand the Authentication Format When you use Retell AI's API, requests need this exact header format :

Authorization: Bearer YOUR_API_KEY

The word "Bearer" must come first, followed by a space, then your actual API key . *Step 3: Configure N8N (General Guidance) * In N8N: 1. Find where you add credentials for Retell AI 2. Look for an authentication type dropdown - select "Bearer Token" or "Header Auth" 3. In the token/key field, paste ONLY your API key (the long string) 4. Do NOT type "Bearer" yourself - N8N should add this automatically 5. Make sure there are no extra spaces before or after your key 6. Save the credential Common Mistakes to Avoid: - Don't include "Bearer " when pasting your key into N8N - Don't add quotes around your API key - Make sure you copied the complete key with no missing characters - Verify the key hasn't been deleted in Retell AI's dashboard If it still doesn't work, try creating a brand new API key in Retell AI and use that fresh key in N8N.

​ To learn more, see the sources I considered: [[1] API Key Overview](https://docs.retellai.com/accounts/api-keys-overview) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

@AI Evy it doesnt work I'm getting same error

### Answer I don't have specific N8N integration documentation in the available sources to provide detailed troubleshooting steps for N8N specifically. However, based on the authorization error you're experiencing, here are some additional things to verify: Check the exact format in N8N: - The authorization header must be exactly:

Authorization: Bearer YOUR_API_KEY

[(1) ]() [(2) ]() [(3) ]() - Ensure N8N is sending this as a header, not as part of the request body - Verify there's exactly one space between "Bearer" and your API key Alternative approach mentioned in community discussions: If N8N's built-in authentication isn't working, you may need to use an HTTP Request node and manually configure the headers [(4) ]() [(5) ]() . Some users have reported needing to use HTTP requests instead of pre-built integrations when authentication issues persist [(4) ]() . Verify your API key is active: - Confirm the key hasn't been deleted from your Retell AI dashboard - Try generating a completely new API key - Make sure you're copying the entire key without any trailing spaces Since the available sources don't contain specific N8N configuration details, I'd recommend: Check out these potentially useful sources: - [Delete Knowledge Base]() - [Delete Agent]() Would you like me to try to answer more generally based on my knowledge of API authentication, or would you prefer to reach

out to Retell AI support directly for N8N-specific guidance?

​ To learn more, see the sources I considered: [[1] Delete Knowledge Base](https://docs.retellai.com/api-references/delete-knowledge-base) [[2] Delete Agent](https://docs.retellai.com/api-references/delete-agent) [[3] End Chat](https://docs.retellai.com/api-references/end-chat) [[4] "Authorization header required"](https://discord.com/channels/1186424376300679209/1417963292327936101) [[5] Authorization/Headers in Custom Tool/Post](https://discord.com/channels/1186424376300679209/1286438010069454911) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer That's the problem - you MUST send the authorization as a header, not in the body. [(1) ]() The Retell AI API requires authentication through headers. Here's what you need to do in N8N: In your N8N HTTP Request node: 1. **URL**: ` 2. **Method**: POST 3. **Authentication**: None (or disable credential-based auth) 4. Headers section - Add a new header: - **Name**:

Authorization

- **Value**:

Bearer YOUR_API_KEY

(replace YOUR_API_KEY with your actual key) 5. **Body**: Your phone call parameters (agent_id, from_number, etc.) The authentication header format must be:

Authorization: Bearer YOUR_API_KEY

Step-by-step for N8N: - Find the "Headers" section in your HTTP Request node - Click "Add Header" or similar button - Enter "Authorization" as the header name - Enter "Bearer " followed by your API key as the value (one space between Bearer and your key) - Keep your request body with your phone call parameters - The header and body are separate - both are needed The API key goes in the header, while your call parameters (like agent_id, phone numbers) go in the body. You need both.

​ To learn more, see the sources I considered: [[1] API Key Overview](https://docs.retellai.com/accounts/api-keys-overview) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer The error message is telling you exactly what's wrong - the header format isn't correct. Double-check these specific things in N8N: 1. **Header name must be exactly**:

Authorization

(capital A, no typos) [(1) ]() 2. **Header value must be exactly**:

Bearer YOUR_ACTUAL_API_KEY

- The word "Bearer" must have a capital "B" [(2) ]() - There must be exactly ONE space after "Bearer" - Then your complete API key with no extra spaces Common mistakes causing this exact error: - Using lowercase "bearer" instead of "Bearer" (case matters for the value) - Missing the space between "Bearer" and your API key - Extra spaces before or after - Not including "Bearer" at all - Including quotes around the value In N8N, it should look like this: Headers section: - Name:

Authorization

- Value:

Bearer sk_abc123...

(your actual key, starting right after the space) NOT like this: - ❌

bearer YOUR_KEY

(lowercase b) - ❌

BearerYOUR_KEY

(no space) - ❌

Bearer  YOUR_KEY

(two spaces) - ❌

"Bearer YOUR_KEY"

(quotes included) - ❌ Just

YOUR_KEY

(missing Bearer) Make sure you're typing "Bearer" with a capital B, followed by exactly one space, then paste your API key.

​ To learn more, see the sources I considered: [[1] Create Batch Call](https://docs.retellai.com/api-references/create-batch-call) [[2] Discord message from @fyodor2572 on 2025-01-13](https://discord.com/channels/1186424376300679209/1186462578310910112/1328208358217613324) ​

​ To learn more, see the sources I considered: [[1] Create Batch Call](https://docs.retellai.com/api-references/create-batch-call) [[2] End Chat](https://docs.retellai.com/api-references/end-chat) [[3] Create Outbound SMS](https://docs.retellai.com/api-references/create-sms-chat) [[4] Update Chat Agent](https://docs.retellai.com/api-references/update-chat-agent) ​

### Answer The format looks correct, but there's one critical issue: that API key format doesn't match Retell AI's standard key format. Retell AI API keys typically start with prefixes like

sk_

or similar, not

key_

. The key you're using (

key_6000d00b0c4989925f0ab4d0ad53

) appears incomplete or may not be a valid Retell AI API key. Here's what to do: 1. Go back to your Retell AI dashboard 2. Navigate to Settings → API Keys 3. Create a brand new API key (click "Add") 4. Copy the COMPLETE key - it should be much longer than what you have 5. The key will likely start with

sk_

or another prefix 6. Use that complete key in N8N In N8N, your header should look like: - Name:

Authorization

- Value:

Bearer sk_abc123def456...

(your full key, which will be much longer) The authorization header format requires "Bearer YOUR_API_KEY" [(1) ]() [(2) ]() [(3) ]() [(4) ]() , and your current key appears to be either truncated or not a valid Retell AI API key. Make absolutely sure: - You're copying the entire key from the Retell AI dashboard - The key hasn't been deleted or deactivated - You're using a key specifically created for API access Try with a fresh, complete API key and the error should resolve.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

Thanks for the follow-up, @Alexander. I'll get back to you soon.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Create Batch Call](https://docs.retellai.com/api-references/create-batch-call) [[2] List Chats](https://docs.retellai.com/api-references/list-chats) ​