diff --git a/rust/crates/rusty-claude-cli/src/main.rs b/rust/crates/rusty-claude-cli/src/main.rs
index 657f3f62..cfa2f56f 100644
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -6433,6 +6433,26 @@ impl LiveCli {
         if action.as_deref() == Some("list") {
             if let Some(filter) = target.as_deref() {
                 if filter.starts_with('-') {
+                    if matches!(output_format, CliOutputFormat::Json) {
+                        // ROADMAP #817: this is a handled local inventory parse error.
+                        // Keep it on stdout in JSON mode so `plugins list --` matches the
+                        // sibling JSON inventory/local surfaces instead of falling through
+                        // to the top-level stderr error path.
+                        let obj = json!({
+                            "type": "error",
+                            "kind": "plugin",
+                            "action": "list",
+                            "status": "error",
+                            "error_kind": "cli_parse",
+                            "error": format!("unknown option for `claw plugins list`: {filter}"),
+                            "message": format!("unknown option for `claw plugins list`: {filter}"),
+                            "unexpected": filter,
+                            "hint": "Usage: claw plugins list [<filter>]\nFilters are id substrings, not flags.",
+                            "exit_code": 1,
+                        });
+                        println!("{}", serde_json::to_string_pretty(&obj)?);
+                        std::process::exit(1);
+                    }
                     return Err(format!(
                         "unknown option for `claw plugins list`: {filter}\nUsage: claw plugins list [<filter>]\nFilters are id substrings, not flags."
                     ).into());
@@ -6513,20 +6533,6 @@ impl LiveCli {
                     }
                 } else if is_list_action {
                     if let Some(filter) = target {
-                        // #793: flag-shaped tokens silently became substring filters on
-                        // plugins list, returning empty success instead of an error.
-                        if filter.starts_with('-') {
-                            let obj = json!({
-                                "kind": "plugin",
-                                "action": "list",
-                                "status": "error",
-                                "error_kind": "unknown_option",
-                                "unexpected": filter,
-                                "hint": "Usage: claw plugins list [<filter>]\nFilters are id substrings, not flags.",
-                            });
-                            println!("{}", serde_json::to_string_pretty(&obj)?);
-                            std::process::exit(1);
-                        }
                         let needle = filter.to_lowercase();
                         payload
                             .plugins
diff --git a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
index fd185158..69efe561 100644
--- a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
+++ b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
@@ -3338,11 +3338,12 @@ fn skills_list_flag_shaped_filter_returns_unknown_option_792() {
 }
 
 #[test]
-fn plugins_list_flag_shaped_filter_returns_unknown_option_793() {
+fn plugins_list_flag_shaped_filter_returns_cli_parse_on_stdout_793_817() {
     // #793: `claw plugins list --bogus-flag` silently returned status:"ok" with empty
     // plugins list instead of an error. The list filter branch in print_plugins treated
     // "--bogus-flag" as an id substring filter and found no matches, producing a false-positive.
-    // Fix: added flag-prefix guard; filter tokens starting with "-" now return unknown_option.
+    // #817: in JSON mode, handled local parse errors now return error_kind:"cli_parse"
+    // on stdout with stderr empty.
     let root = unique_temp_dir("plugins-list-flag-793");
     fs::create_dir_all(&root).expect("temp dir");
     std::process::Command::new("git")
@@ -3366,19 +3367,16 @@ fn plugins_list_flag_shaped_filter_returns_unknown_option_793() {
         !output.status.success(),
         "plugins list --unknown-flag must exit non-zero (#793)"
     );
-    // #803: the early flag guard now returns Err before the JSON branch,
-    // so the error envelope goes to stderr via the main error handler.
-    let stderr = String::from_utf8_lossy(&output.stderr);
-    let j: serde_json::Value = stderr
-        .lines()
-        .find(|l| l.trim_start().starts_with('{'))
-        .and_then(|l| serde_json::from_str(l).ok())
-        .expect("plugins list flag-filter should emit valid JSON on stderr");
+    assert_eq!(output.status.code(), Some(1), "exit code must be 1 (#817)");
+    // #817: handled JSON local parse errors stay on stdout, with stderr empty.
     assert!(
-        j["error_kind"] == "unknown_option" || j["error_kind"] == "cli_parse",
-        "plugins list flag-shaped filter must return typed error, got {:?}",
-        j["error_kind"]
+        output.stderr.is_empty(),
+        "plugins list flag-filter JSON error must keep stderr empty (#817), got: {}",
+        String::from_utf8_lossy(&output.stderr)
     );
+    let j: serde_json::Value = serde_json::from_slice(&output.stdout)
+        .expect("plugins list flag-filter should emit valid JSON on stdout");
+    assert_eq!(j["error_kind"], "cli_parse");
     assert_eq!(j["status"], "error");
     let h = j["hint"]
         .as_str()
@@ -3697,6 +3695,62 @@ fn plugins_extra_args_have_non_null_hint_797() {
     );
 }
 
+#[test]
+fn plugins_list_trailing_dash_json_error_uses_stdout_817() {
+    // ROADMAP #817: JSON inventory/local parse errors are machine-readable on
+    // stdout. `plugins list --` used to route through the top-level error path,
+    // leaving stdout empty and writing the JSON envelope to stderr.
+    let root = unique_temp_dir("plugins-list-dash-817");
+    fs::create_dir_all(&root).expect("temp dir");
+
+    let output = run_claw(
+        &root,
+        &["--output-format", "json", "plugins", "list", "--"],
+        &[],
+    );
+    assert!(
+        !output.status.success(),
+        "plugins list -- must exit non-zero (#817)"
+    );
+    assert_eq!(output.status.code(), Some(1), "exit code must be 1 (#817)");
+    assert!(
+        output.stderr.is_empty(),
+        "JSON parse error must keep stderr empty (#817), got: {}",
+        String::from_utf8_lossy(&output.stderr)
+    );
+    let j: serde_json::Value =
+        serde_json::from_slice(&output.stdout).expect("stdout should be JSON error (#817)");
+    assert_eq!(j["kind"], "plugin");
+    assert_eq!(j["action"], "list");
+    assert_eq!(j["status"], "error");
+    assert_eq!(j["error_kind"], "cli_parse");
+    assert_eq!(j["unexpected"], "--");
+}
+
+#[test]
+fn plugins_list_trailing_dash_text_error_stays_on_stderr_817() {
+    let root = unique_temp_dir("plugins-list-dash-text-817");
+    fs::create_dir_all(&root).expect("temp dir");
+
+    let output = run_claw(&root, &["plugins", "list", "--"], &[]);
+    assert!(
+        !output.status.success(),
+        "plugins list -- text mode must exit non-zero (#817)"
+    );
+    assert_eq!(output.status.code(), Some(1), "exit code must be 1 (#817)");
+    assert!(
+        output.stdout.is_empty(),
+        "text parse error should not emit stdout (#817), got: {}",
+        String::from_utf8_lossy(&output.stdout)
+    );
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    assert!(stderr.contains("[error-kind: cli_parse]"), "{stderr}");
+    assert!(
+        stderr.contains("unknown option for `claw plugins list`: --"),
+        "{stderr}"
+    );
+}
+
 #[test]
 fn empty_prompt_has_non_null_hint_798() {
     // #798: `claw --output-format json ""` returned empty_prompt + hint:null.