CF-Incidents Workers - Control which routes invoke your Worker script for Single Page Applications

[ENF News Bot]

For those building Single Page Applications (SPAs) on Workers, you can now explicitly define which routes invoke your Worker script in Wrangler configuration. The run_worker_first config option has now been expanded to accept an array of route patterns, allowing you to more granularly specify when your Worker script runs.

Configuration example:

{
	"name": "my-spa-worker",
	// Set this to today's date
	"compatibility_date": "2026-11-12",
	"main": "./src/index.ts",
	"assets": {
		"directory": "./dist/",
		"not_found_handling": "single-page-application",
		"binding": "ASSETS",
		"run_worker_first": ["/api/*", "!/api/docs/*"]
	}
}

name = "my-spa-worker"
# Set this to today's date
compatibility_date = "2026-11-12"
main = "./src/index.ts"

[assets]
directory = "./dist/"
not_found_handling = "single-page-application"
binding = "ASSETS"
run_worker_first = [ "/api/*", "!/api/docs/*" ]

This new routing control was done in partnership with our community and customers who provided great feedback on our public proposal ↗︎. Thank you to everyone who brought forward use-cases and feedback on the design!

Prerequisites​

https://developers.cloudflare.com/changelog/rss/#prerequisites

To use advanced routing control with run_worker_first, you'll need:

• Wrangler v4.20.0 and above
• Cloudflare Vite plugin v1.7.0 and above

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