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Preview Proxy

AIO Sandbox includes built-in proxy endpoints that allow you to preview and test web applications and services directly from your development environment.

SubDomain Proxy(Recommend)

Any domain name that satisfies the ${port}-${domain} format will be forwarded to the corresponding port within the sandbox.

Header-Based Port Routing

When a public gateway or custom reverse proxy cannot use the ${port}-${domain} host format, it can route preview traffic by injecting the x-aio-proxy-port request header:

curl -H 'x-aio-proxy-port: 19877' \
  https://<sandbox-public-host>/some/path

The sandbox forwards the request to http://127.0.0.1:19877/some/path. The original path is preserved, and the control header is removed before the request reaches the target service.

Only pure numeric header values enable this routing. Because the header selects an internal sandbox port, it should be overwritten by a trusted gateway or reverse proxy instead of being accepted directly from end users.

SubPath Proxy Types

Frontend Application Proxy

Access frontend applications using the absolute proxy:

http://localhost:8080/absproxy/{port}/

Use cases:

  • React, Vue, Angular applications
  • Static site generators
  • Development servers with asset bundling
  • Any frontend framework with dev server

Example:

# Start a React app on port 3000
cd /workspace/my-react-app
npm start

# Access via proxy
# Browser: http://localhost:8080/absproxy/3000/

Backend Service Proxy

Access backend services using the relative proxy:

http://localhost:8080/proxy/{port}/

Use cases:

  • API servers
  • Backend microservices
  • Database admin interfaces
  • Development tools and utilities

Example:

# Start an Express API on port 4000
cd /workspace/my-api
npm start

# Access via proxy
# API endpoint: http://localhost:8080/proxy/4000/api/users

Next Steps

  • Terminal Integration: Control services via shell → Shell API
  • File Operations: Manage application files → File API
  • Browser Automation: Test applications → Browser Guide
  • Advanced Proxy And Network: Configure outbound proxy and runtime mappings → Proxy And Network