Based on the documentation, you're experiencing expected behavior with OPA v1 and

import rego.v1

. Let me clarify what's happening: Understanding

import rego.v1

vs Package

.v1

Suffix The

import rego.v1

statement you're using is actually the modern way to enable OPA v1 compatibility (1) . When you use

import rego.v1

, it automatically enables v1 syntax for that entire module, making the

.v1

package suffix unnecessary . How Compatibility Mode Works According to the migration guide, when

OPAL_OPA_V0_COMPAT

is set (2) : • `true`: OPA accepts both v0 and v1 syntax • `false`: OPA runs in strict v1 mode The compatibility mode is controlled by the

OPAL_OPA_V0_COMPAT

setting, which can be configured as :

# Enable v0 compatibility (default in v0.9.x)  
export OPAL_OPA_V0_COMPAT=true  
  
# Disable v0 compatibility  
export OPAL_OPA_V0_COMPAT=false

Why Your Policies Still Work Your policies continue to work because you're using

import rego.v1

, which is the correct v1 syntax (1) . The migration guide shows two approaches (2) : 1. Adding

.v1

suffix to package declarations 2. Using

import rego.v1

(which you're already doing) Since you're using

import rego.v1

, your policies are already v1-compliant, which is why they work even with compatibility mode disabled. OPAL 0.9.x Defaults In OPAL v0.9.x,

OPAL_OPA_V0_COMPAT

defaults to

true

for easier migration . The documentation states that OPAL v0.10.0+ will have this unconfigured (effectively

false

) by default . Your understanding is correct - you've already migrated to v1 syntax by using

import rego.v1

, so disabling compatibility mode doesn't break your policies.

To learn more, see the sources I considered: [[1] OPA v1 is Almost Out! Here’s What You Need to Know](https://www.permit.io/blog/whats-new-on-opa-v1) [[2] OPA Version Migration Guide](https://docs.opal.ac/tutorials/opa-version-migration)