fix: fixed variable inputs

server/internal/services/workflow_runner.go

@@ -2,6 +2,7 @@ package services
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"time"
 
@@ -188,9 +189,19 @@ func runServer(runID string, srvIdx int, steps []models.ResolvedStep, serverID s
 		for k, v := range secretVals {
 			allSecrets[k] = v
 		}
+		// Input values may template earlier step outputs and secrets, e.g.
+		// URL="http://example.com/$VersionNumber". Expand against runEnv (outputs
+		// threaded from prior steps) and this step's secrets before dispatch.
+		subst := map[string]string{}
+		for k, v := range runEnv {
+			subst[k] = v
+		}
+		for k, v := range secretVals {
+			subst[k] = v
+		}
 		cmdEnv := map[string]string{}
 		for k, v := range step.Inputs {
-			cmdEnv[k] = v
+			cmdEnv[k] = expandVars(v, subst)
 		}
 		for k, v := range runEnv {
 			cmdEnv[k] = v
@@ -310,6 +321,18 @@ func dispatchAndWait(serverID, commandID string, cmd *pb.RunStepCmd) *pb.StepRes
 	}
 }
 
+// expandVars substitutes $VAR and ${VAR} references in an input value from the
+// given lookup (prior step outputs and secrets). Unknown references expand to
+// empty, matching shell behaviour; a literal "$" is written as "$$".
+func expandVars(v string, lookup map[string]string) string {
+	return os.Expand(v, func(name string) string {
+		if name == "$" {
+			return "$"
+		}
+		return lookup[name]
+	})
+}
+
 func resolveSecrets(refs []string) map[string]string {
 	out := map[string]string{}
 	for _, ref := range refs {