humanlayer/examples/flask

HumanLayer Flask Example

This example demonstrates how to use HumanLayer with Flask in two ways:

1. Simple approvals with app.py
2. Webhook-based approvals with app-webhooks.py

Table of Contents

• Setup
• Simple Approvals (app.py)
  • Running the Application
  • Testing the Endpoints
  • Example Responses
• Webhook Approvals (app-webhooks.py)
  • Setup Webhooks
  • Running the Application
  • Testing the Endpoints
  • Example Responses

Setup

1. Create a virtual environment and activate it:

   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate
   

2. Install dependencies:

   pip install -r requirements.txt
   

3. Copy .env.example to .env and fill in your API keys:

   cp .env.example .env
   # Add your keys to .env:
   # HUMANLAYER_API_KEY=your_key_here
   

Simple Approvals

The app.py example shows basic HumanLayer integration where the API waits for approval before returning a response.

Running Simple

Start the server:

python app.py

Testing Simple

Test the agent with a very basic prompt:

curl "http://localhost:8000/run?prompt=yo"

{
  "status": "success",
  "message": "how can I help you?"
}

You can send a prompt that uses math to trigger the approval logic

# Test the agent with a prompt
curl "http://localhost:8000/run?prompt=what+is+2+plus+2"

Responses Simple

The endpoint will wait for approval and then return:

{
  "status": "success",
  "result": "2 plus 2 equals 4"
}

Webhook Approvals

The app-webhooks.py example demonstrates a more advanced pattern using webhooks for asynchronous approvals.

Setup Webhooks

1. Get an ngrok.com account and claim your free static subdomain

2. Set up response webhooks in the HumanLayer dashboard:

   • Go to Settings > Webhooks
   • Add webhook: https://your-subdomain.ngrok-free.app/webhook/inbound
   • Save the webhook configuration

3. Start ngrok pointing to your Flask app:

   ngrok http 8000 --domain=your-subdomain.ngrok-free.app
   

Running the app

Start the server in a separate terminal:

python app-webhooks.py

Testing Webhooks

1. Make a request:

   curl "http://localhost:8000/run?prompt=calculate%202%20plus%202"
   

2. Note the function call ID in the response:

   {
     "status": "pending",
     "call_id": "abc123"
   }
   

3. Check the status using the call_id in the url path

   curl "http://localhost:8000/run/abc123"
   

4. Approve the action in HumanLayer (via Slack or dashboard)

5. The webhook will receive the approval and update the status

6. Check the status again to see the result:

   curl "http://localhost:8000/run/abc123"
   

Responses Webhooks

Initial request:

{
  "status": "pending",
  "call_id": "abc123"
}

Checking status before approval:

{
  "status": "pending",
  "message": "Waiting for approval, refresh to check status"
}

After approval:

{
  "status": "success",
  "result": "2 plus 2 equals 4"
}

View all function calls:

curl "http://localhost:8000/function-calls"

Response:

{
  "function_calls": [
    {
      "call_id": "abc123",
      "status": "approved",
      "result": "2 plus 2 equals 4"
    }
  ]
}