A tools bundle is given its words, composed per machine; what they name is the account's to read (hq ADR 0192)

build.artifacts[].env on a bundle: words and values written with ${dir:…} and ${port:…} only,
refused when a value carries any other reference (a secret's content, a binding) or names a word
the runtime sets for itself, and on any artifact that is not a bundle. Resolved per machine like a
container's environment and handed to the runtime as MESH_TOOL_ENV, module by module, in the unit
so a change restarts it. Every file and directory of the module a word names, or that holds one, is
owned by the account the runtime runs as where it says no owner, since a tool reads as that account.

internal/catalogue/manifest.go

@@ -602,6 +602,8 @@ type Bundle struct {
 	// every entrypoint for a module declaring tools that said nothing. Empty for a bundle that is
 	// run rather than loaded.
 	Loads []string `json:"loads,omitempty"`
+	// Env is what the artifact said it is given (ADR 0192), as written; composed per machine.
+	Env map[string]string `json:"env,omitempty"`
 }
 
 // Build says how to produce this module's artifacts from its source.
@@ -748,6 +750,11 @@ type Artifact struct {
 	// module's tools and nothing else is the ordinary case and should not have to say the same
 	// list twice. A module declaring no tools has nothing the runtime loads, whatever it compiles.
 	Loads []string `json:"loads,omitempty"`
+
+	// Env is what a tools bundle is given on a machine (novox/hq ADR 0192): words and their values,
+	// paths and constants composed with ${dir:…} and ${port:…} exactly as a container's environment
+	// is, never a secret's content. The node's runtime hands it to this bundle and to no other.
+	Env map[string]string `json:"env,omitempty"`
 }
 
 // Kinds an artifact may be.