Code Management

Code Management

ERA Agent allows you to store code directly in a session and update it at any time. This is perfect for iterative development, webhooks, APIs, and long-running services where you want to improve the code without changing the public URL.

Tip

Key Benefit: Your public proxy URL stays the same even when you update the code! Perfect for webhooks and callbacks where the URL is registered with external services.

Quick Start

1. Create a Session

curl -X POST https://anewera.dev/api/sessions \
  -H "Content-Type: application/json" \
  -d '{
    "language": "python",
    "session_id": "my-api",
    "persistent": true,
    "allowPublicAccess": true
  }'

2. Store Initial Code

curl -X PUT https://anewera.dev/api/sessions/my-api/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "print(\"Hello from ERA!\")",
    "description": "Initial version"
  }'

3. Run the Stored Code

When you run without providing code, it automatically uses the stored code:

# No "code" field needed - uses stored code
curl -X POST https://anewera.dev/api/sessions/my-api/run \
  -H "Content-Type: application/json" \
  -d '{}'

Or via proxy URL:

curl https://anewera.dev/proxy/my-api/8000/test

4. Update the Code

curl -X PUT https://anewera.dev/api/sessions/my-api/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "print(\"Updated version 2!\")",
    "description": "Added new features"
  }'

Note

The next execution automatically uses the updated code. No redeployment needed!

Iterative Development Workflow

Example: Building a Webhook Handler

Step 1: Start Simple

# Create session
curl -X POST https://anewera.dev/api/sessions \
  -H "Content-Type: application/json" \
  -d '{
    "session_id": "stripe-webhook",
    "language": "python",
    "persistent": true,
    "allowPublicAccess": true
  }'

# Store basic handler (v1)
curl -X PUT https://anewera.dev/api/sessions/stripe-webhook/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "import os, json\nif os.getenv(\"ERA_REQUEST_MODE\") == \"proxy\":\n    print(json.dumps({\"status\": \"received\", \"version\": 1}))",
    "description": "v1: Basic webhook receiver"
  }'

# Get public URL
curl https://anewera.dev/api/sessions/stripe-webhook/host?port=8000
# URL: https://anewera.dev/proxy/stripe-webhook/8000

Step 2: Add Validation

curl -X PUT https://anewera.dev/api/sessions/stripe-webhook/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "import os, json\nif os.getenv(\"ERA_REQUEST_MODE\") == \"proxy\":\n    method = os.getenv(\"ERA_HTTP_METHOD\")\n    if method != \"POST\":\n        print(json.dumps({\"error\": \"Only POST allowed\"}))\n    else:\n        print(json.dumps({\"status\": \"received\", \"version\": 2}))",
    "description": "v2: Added method validation"
  }'

Step 3: Process Payload

curl -X PUT https://anewera.dev/api/sessions/stripe-webhook/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "import os, json\nif os.getenv(\"ERA_REQUEST_MODE\") == \"proxy\":\n    body = os.getenv(\"ERA_HTTP_BODY\")\n    data = json.loads(body or \"{}\")\n    event_type = data.get(\"type\")\n    print(json.dumps({\"status\": \"processed\", \"event\": event_type, \"version\": 3}))",
    "description": "v3: Processing webhook payload"
  }'

Tip

Same URL Throughout! Your webhook URL never changed - you just kept improving the code behind it.

API Reference

Store/Update Code

Endpoint: PUT /api/sessions/{session_id}/code

Request Body:

{
  "code": "string (required)",
  "description": "string (optional)"
}

Response:

{
  "success": true,
  "code_length": 245,
  "updated_at": "2025-10-24T06:43:17.661Z"
}

Example:

curl -X PUT https://anewera.dev/api/sessions/my-session/code \
  -H "Content-Type: application/json" \
  -d '{
    "code": "print(\"Hello World\")",
    "description": "Initial implementation"
  }'

Get Stored Code

Endpoint: GET /api/sessions/{session_id}/code

Response:

{
  "code": "print(\"Hello World\")",
  "description": "Initial implementation",
  "updated_at": "2025-10-24T06:43:17.661Z",
  "code_length": 19
}

Example:

curl https://anewera.dev/api/sessions/my-session/code

Complete Examples

Python: API with Multiple Routes

api_handler.py

import os
import json

if os.getenv("ERA_REQUEST_MODE") == "proxy":
  method = os.getenv("ERA_HTTP_METHOD")
  path = os.getenv("ERA_HTTP_PATH")

  # Route handling
  if path == "/users" and method == "GET":
      response = {
          "users": [
              {"id": 1, "name": "Alice"},
              {"id": 2, "name": "Bob"}
          ],
          "version": "1.0.0"
      }
  elif path == "/status":
      response = {"status": "online", "version": "1.0.0"}
  else:
      response = {"error": "Not found", "path": path}

  print(json.dumps(response))

Store it:

curl -X PUT https://anewera.dev/api/sessions/my-api/code \
  -H "Content-Type: application/json" \
  -d @- <<'EOF'
{
  "code": "import os\nimport json\n\nif os.getenv(\"ERA_REQUEST_MODE\") == \"proxy\":\n    method = os.getenv(\"ERA_HTTP_METHOD\")\n    path = os.getenv(\"ERA_HTTP_PATH\")\n    \n    if path == \"/users\" and method == \"GET\":\n        response = {\"users\": [{\"id\": 1, \"name\": \"Alice\"}]}\n    elif path == \"/status\":\n        response = {\"status\": \"online\"}\n    else:\n        response = {\"error\": \"Not found\"}\n    \n    print(json.dumps(response))",
  "description": "API with routes"
}
EOF

JavaScript: Event Handler

event_handler.js

const os = require('os');

if (process.env.ERA_REQUEST_MODE === 'proxy') {
  const method = process.env.ERA_HTTP_METHOD;
  const body = JSON.parse(process.env.ERA_HTTP_BODY || '{}');

  // Process event
  const response = {
      received: body,
      processed_at: new Date().toISOString(),
      version: '2.0.0'
  };

  console.log(JSON.stringify(response));
}

TypeScript: Data Processor

processor.ts

interface RequestData {
  action: string;
  payload: any;
}

if (process.env.ERA_REQUEST_MODE === 'proxy') {
  const body: RequestData = JSON.parse(
      process.env.ERA_HTTP_BODY || '{}'
  );

  let response: any;

  switch (body.action) {
      case 'process':
          response = {
              status: 'processed',
              result: body.payload
          };
          break;
      default:
          response = {
              error: 'Unknown action',
              received: body.action
          };
  }

  console.log(JSON.stringify(response));
}

Run Behavior

With Stored Code

If you have stored code and run without providing code:

curl -X POST https://anewera.dev/api/sessions/my-session/run \
  -H "Content-Type: application/json" \
  -d '{}'

→ Uses stored code

Override Stored Code

You can override stored code for one-off executions:

curl -X POST https://anewera.dev/api/sessions/my-session/run \
  -H "Content-Type: application/json" \
  -d '{
    "code": "print(\"One-time test\")"
  }'

→ Uses provided code, stored code remains unchanged

No Stored Code

If there’s no stored code and you don’t provide code:

curl -X POST https://anewera.dev/api/sessions/my-session/run \
  -H "Content-Type: application/json" \
  -d '{}'

→ Error: “code is required or must be stored”

Best Practices

1. Use Descriptive Session IDs

✅ Good: "stripe-webhook", "api-v2", "data-processor"
❌ Bad: "test1", "temp", "abc123"

2. Add Version Numbers

# Include version in your code responses
response = {
    "version": "2.1.0",
    "data": result
}

3. Document Changes

# Use descriptions to track what changed
curl -X PUT .../code \
  -d '{
    "code": "...",
    "description": "v2.1: Added error handling for edge cases"
  }'

4. Test After Updates

# Always test after updating
curl -X PUT .../code -d '{"code": "..."}'
# Then immediately test
curl .../proxy/my-session/8000/test

5. Keep Backups

# Download current code before major updates
curl https://anewera.dev/api/sessions/my-session/code > backup.json

Use Cases

1. Webhook Handlers

Update your webhook processing logic without re-registering with external services:

# Register once with Stripe/GitHub/etc
URL: https://anewera.dev/proxy/webhook/8000

# Update handler anytime
curl -X PUT .../webhook/code -d '{"code": "new_logic"}'

2. API Endpoints

Iterate on your API without changing URLs:

# Share API URL with clients
URL: https://anewera.dev/proxy/api-v1/8000

# Add features, fix bugs, improve performance
curl -X PUT .../api-v1/code -d '{"code": "improved_version"}'

3. Interactive Demos

Create live coding demonstrations:

# Share demo URL in presentation
URL: https://anewera.dev/proxy/demo/8000

# Update demo code during presentation
curl -X PUT .../demo/code -d '{"code": "next_example"}'

4. Scheduled Jobs

Store processing logic that runs on a schedule:

# Store data processing code
curl -X PUT .../daily-report/code -d '{"code": "generate_report"}'

# External scheduler hits endpoint daily
URL: https://anewera.dev/proxy/daily-report/8000

Limitations

• Code Size: Stored in Durable Object storage (limit: ~128KB per value)
• No Versioning: Only current version is stored (implement your own versioning if needed)
• No Rollback: Save backups externally if you need rollback capability

Next Steps

• Learn about Callbacks & Webhooks for receiving HTTP requests
• See File Operations for managing data
• Check Environment Variables for available runtime info