Issue Summary
My Shopify app proxy configuration works perfectly for GET requests but completely blocks POST requests from reaching my backend server. POST requests return 302 redirects and
never arrive at the backend.
Configuration Details
shopify.app.toml:
[access_scopes]
scopes = “read_products,write_products,read_customers,write_customers,read_orders,write_orders,write_app_proxy”
[app_proxy]
url = “https://my-backend.example.com”
prefix = “apps”
subpath = “api”
Expected URL mapping:
- ‘the_proxy_urlt_hat_i_cant_show_here_because_of_message_limitation’ → https://my-backend.example.com/projects
What Works 
GET requests work perfectly:
curl ‘the_proxy_urlt_hat_i_cant_show_here_because_of_message_limitation’
Returns: 400 with proper Laravel validation response
Backend logs show: Request received and processed
What Doesn’t Work 
All POST requests fail:
Simple POST request
curl -X POST ‘the_proxy_urlt_hat_i_cant_show_here_because_of_message_limitation‘
-H ‘Content-Type: application/json’
-d ‘{“name”:“Test”,“status”:“draft”}’
Returns: 302 redirect, backend receives NOTHING
Tested variations (all fail with 302)
- POST without cookies
- POST without Origin header
- POST with browser headers
- POST with URL ending in dot (.)
- Different payload sizes
Backend Investigation
Direct backend testing works:
curl -X POST ‘https://my-backend.example.com/projects’
-H ‘Content-Type: application/json’
-d ‘{“name”:“Test”,“status”:“draft”}’
Returns: 400 with Laravel validation (expected)
Backend logs analysis
- GET requests from app proxy appear in nginx logs
- POST requests from app proxy NEVER appear in logs
- Direct POST requests to backend work fine
Environment Details
- Shopify CLI: Latest (2025)
- Backend: Laravel 12 on Docker/nginx
- App Type: Public app with embedded admin
- Testing: Development store
Questions
- Is this a known limitation? Does Shopify app proxy support POST requests ? It worked 1 month ago
- Configuration issue? Is there a specific configuration needed in shopify.app.toml to enable POST request forwarding?
Attempted Solutions
- Verified write_app_proxy scope is granted
- Tested various curl configurations
- Confirmed backend accepts requests directly
- Checked nginx logs extensively
The GET/POST inconsistency suggests either a configuration issue or a fundamental limitation of Shopify app proxy for POST requests. Any insights would be greatly appreciated!
