Compatibility dates

This platform has one effective compatibility date: effective_compatibility_date from the formal runtime lock, currently 2026-08-30. Projects cannot choose a date.

ocd capabilities --json

Read runtime.effective_compatibility_date. The live value is the JSON on the node.

The meaning of the date matches Cloudflare: it selects workerd's observable behavior as of that day. See Cloudflare compatibility dates.

Compatibility

Topic	Cloudflare	open-compute
Date selects workerd observable behavior	Yes	Yes
Per-project compatibility_date / compatibilityDate	Yes	Not allowed; putting one in open-compute.json is an unknown field and fails
How the date changes	Project config	Changing the platform pin (workerd.lock.json)