Support multi-version deploys or --old-asset-ttl for wrangler versions deploy

[bmbferreira]

Description

We deploy Cloudflare Workers multiple times per day and are currently running into issues with asset invalidation during version rollouts.

When deploying new versions using wrangler versions deploy, older static assets can become unavailable too quickly. This leads to situations where users with an already loaded application (SPA) experience broken states unless they refresh their browser.

We would like a way to keep older versions (or at least their assets) available for a longer period to ensure smooth transitions between deployments.

Problem

Currently:

• Deploying a new version can invalidate older assets quickly
• Users with cached HTML/JS referencing previous asset versions may encounter errors
• This forces us to either:
  • Prompt users to refresh, or
  • Accept broken sessions during deploys

Given that we deploy frequently, this negatively impacts user experience.

Proposed Solutions

Option 1: Multi-version deploy with traffic allocation

Allow deploying multiple versions at once with explicit traffic weights, for example:

wrangler versions deploy <version1>@100 <version2>@0 <version3>@0

The main issue is that this is currently limited to 2 versions, we would like to have more versions available.

This would:

• Keep multiple versions active simultaneously
• Allow gradual migration of traffic
• Enable use of Worker affinity to keep users on the same version
• Prevent breaking users already on older versions

Option 2: Support --old-asset-ttl for versions deploy

Extend wrangler versions deploy to support:

wrangler versions deploy --old-asset-ttl=3600

This would:

• Keep previous static assets available for a configurable duration
• Reduce the need for forced refreshes or user prompts

Why this matters

• We deploy multiple times per day
• Our app is sensitive to asset/version mismatches
• Smooth rollout is critical to avoid user disruption
• Current gradual deployment tools do not fully solve asset availability issues

References

• https://developers.cloudflare.com/workers/configuration/versions-and-deployments/gradual-deployments/
• https://developers.cloudflare.com/workers/static-assets/routing/advanced/gradual-rollouts/