Check the compiled language version before packaging a managed application

Source facts

Azure Managed Applications support ARM template languageVersion 1.0, not 2.0. Bicep-authored application resources must therefore be converted to the mainTemplate.json file used by the definition. The documentation calls for checking the converted JSON for accuracy before packaging. A build result and the managed application’s template-compatibility requirement are separate checks. Microsoft Learn.

Applicability

Use this acceptance gate when changing Bicep features or the build process for a managed application. Inspect the generated mainTemplate.json that will actually enter the package, not only the source file or a different deployment template used to publish the definition.

DSE recommendation

DSE recommends validating the generated deployment template against the managed application’s supported language version before packaging it. Preserve the source revision and generated artifact together. If a language feature causes incompatible output, stop the package release and redesign that feature for the supported target rather than assuming the compiler’s success establishes product support. Keep the intended resource behavior covered by separate tests.

Verification

Build the proposed source in the approved toolchain and examine the resulting template language. Recheck the exact JSON after it is placed in the package, then test the definition and an application instance in a controlled subscription. Record compatibility and deployment behavior separately. Do not treat a catalog definition appearing successfully as proof that its packaged resources have been deployed or validated.

Official references

Microsoft Learn. Source retrieved September 9, 2026.