diff --git a/README.md b/README.md
index 64b2570..131f8e5 100644
--- a/README.md
+++ b/README.md
@@ -572,7 +572,7 @@ server: https://your-amcs-server
 token: your-bearer-token
 ```
 
-Env vars override the config file: `AMCS_URL`, `AMCS_TOKEN`. Flags `--server` and `--token` override env vars.
+Env vars override the config file: `AMCS_SERVER` (preferred), `AMCS_URL` (legacy alias), and `AMCS_TOKEN`. Flags `--server` and `--token` override env vars.
 
 ### stdio MCP client setup
 
@@ -586,7 +586,7 @@ With inline credentials (no config file):
 
 ```bash
 claude mcp add --transport stdio amcs amcs-cli stdio \
-  --env AMCS_URL=https://your-amcs-server \
+  --env AMCS_SERVER=https://your-amcs-server \
   --env AMCS_TOKEN=your-bearer-token
 ```
 
diff --git a/cmd/amcs-cli/cmd/root.go b/cmd/amcs-cli/cmd/root.go
index 3c49bda..2ff540c 100644
--- a/cmd/amcs-cli/cmd/root.go
+++ b/cmd/amcs-cli/cmd/root.go
@@ -54,6 +54,9 @@ func loadConfig() error {
 		return err
 	}
 	cfg = loaded
+	if v := strings.TrimSpace(os.Getenv("AMCS_SERVER")); v != "" {
+		cfg.Server = v
+	}
 	if v := strings.TrimSpace(os.Getenv("AMCS_URL")); v != "" {
 		cfg.Server = v
 	}
@@ -75,7 +78,7 @@ func loadConfig() error {
 
 func requireServer() error {
 	if strings.TrimSpace(cfg.Server) == "" {
-		return fmt.Errorf("server URL is required; set --server, AMCS_URL, or config server")
+		return fmt.Errorf("server URL is required; set --server, AMCS_SERVER, AMCS_URL, or config server")
 	}
 	return nil
 }