# Jsonnet Any file matching `*.jsonnet` in a directory app is treated as a Jsonnet file. ArgoCD evaluates the Jsonnet and is able to parse a generated object or array. ## Build Environment > v1.4 Jsonnet apps have access to the [standard build environment](build-environment.md) via substitution into *TLAs* and *external variables*. It is also possible to add a shared library (e.g. `vendor` folder) relative to the repository root. E.g. via the CLI: ```bash argocd app create APPNAME \ --jsonnet-ext-str 'app=${ARGOCD_APP_NAME}' \ --jsonnet-tla-str 'ns=${ARGOCD_APP_NAMESPACE}' \ --jsonnet-libs 'vendor' ``` Or by declarative syntax: ```yaml directory: jsonnet: extVars: - name: app value: $ARGOCD_APP_NAME tlas: - name: ns value: $ARGOCD_APP_NAMESPACE libs: - vendor ```