[MCP] Redact environment variable values in /mcp and mcp get (#5648)

Fixes #5524

codex-rs/tui/src/history_cell.rs

@@ -1047,7 +1047,10 @@ pub(crate) fn new_mcp_tools_output(
         return PlainHistoryCell { lines };
     }
 
-    for (server, cfg) in config.mcp_servers.iter() {
+    let mut servers: Vec<_> = config.mcp_servers.iter().collect();
+    servers.sort_by(|(a, _), (b, _)| a.cmp(b));
+
+    for (server, cfg) in servers {
         let prefix = format!("mcp__{server}__");
         let mut names: Vec<String> = tools
             .keys()
@@ -1111,7 +1114,7 @@ pub(crate) fn new_mcp_tools_output(
                     pairs.sort_by(|(a, _), (b, _)| a.cmp(b));
                     let display = pairs
                         .into_iter()
-                        .map(|(name, value)| format!("{name}={value}"))
+                        .map(|(name, _)| format!("{name}=*****"))
                         .collect::<Vec<_>>()
                         .join(", ");
                     lines.push(vec!["    • HTTP headers: ".into(), display.into()].into());
@@ -1123,7 +1126,7 @@ pub(crate) fn new_mcp_tools_output(
                     pairs.sort_by(|(a, _), (b, _)| a.cmp(b));
                     let display = pairs
                         .into_iter()
-                        .map(|(name, env_var)| format!("{name}={env_var}"))
+                        .map(|(name, var)| format!("{name}={var}"))
                         .collect::<Vec<_>>()
                         .join(", ");
                     lines.push(vec!["    • Env HTTP headers: ".into(), display.into()].into());
@@ -1415,14 +1418,20 @@ mod tests {
     use codex_core::config::Config;
     use codex_core::config::ConfigOverrides;
     use codex_core::config::ConfigToml;
+    use codex_core::config_types::McpServerConfig;
+    use codex_core::config_types::McpServerTransportConfig;
+    use codex_core::protocol::McpAuthStatus;
     use codex_protocol::parse_command::ParsedCommand;
     use dirs::home_dir;
     use pretty_assertions::assert_eq;
     use serde_json::json;
+    use std::collections::HashMap;
 
     use mcp_types::CallToolResult;
     use mcp_types::ContentBlock;
     use mcp_types::TextContent;
+    use mcp_types::Tool;
+    use mcp_types::ToolInputSchema;
 
     fn test_config() -> Config {
         Config::load_from_base_config_with_overrides(
@@ -1449,6 +1458,91 @@ mod tests {
         render_lines(&cell.transcript_lines(u16::MAX))
     }
 
+    #[test]
+    fn mcp_tools_output_masks_sensitive_values() {
+        let mut config = test_config();
+        let mut env = HashMap::new();
+        env.insert("TOKEN".to_string(), "secret".to_string());
+        let stdio_config = McpServerConfig {
+            transport: McpServerTransportConfig::Stdio {
+                command: "docs-server".to_string(),
+                args: vec![],
+                env: Some(env),
+                env_vars: vec!["APP_TOKEN".to_string()],
+                cwd: None,
+            },
+            enabled: true,
+            startup_timeout_sec: None,
+            tool_timeout_sec: None,
+            enabled_tools: None,
+            disabled_tools: None,
+        };
+        config.mcp_servers.insert("docs".to_string(), stdio_config);
+
+        let mut headers = HashMap::new();
+        headers.insert("Authorization".to_string(), "Bearer secret".to_string());
+        let mut env_headers = HashMap::new();
+        env_headers.insert("X-API-Key".to_string(), "API_KEY_ENV".to_string());
+        let http_config = McpServerConfig {
+            transport: McpServerTransportConfig::StreamableHttp {
+                url: "https://example.com/mcp".to_string(),
+                bearer_token_env_var: Some("MCP_TOKEN".to_string()),
+                http_headers: Some(headers),
+                env_http_headers: Some(env_headers),
+            },
+            enabled: true,
+            startup_timeout_sec: None,
+            tool_timeout_sec: None,
+            enabled_tools: None,
+            disabled_tools: None,
+        };
+        config.mcp_servers.insert("http".to_string(), http_config);
+
+        let mut tools: HashMap<String, Tool> = HashMap::new();
+        tools.insert(
+            "mcp__docs__list".to_string(),
+            Tool {
+                annotations: None,
+                description: None,
+                input_schema: ToolInputSchema {
+                    properties: None,
+                    required: None,
+                    r#type: "object".to_string(),
+                },
+                name: "list".to_string(),
+                output_schema: None,
+                title: None,
+            },
+        );
+        tools.insert(
+            "mcp__http__ping".to_string(),
+            Tool {
+                annotations: None,
+                description: None,
+                input_schema: ToolInputSchema {
+                    properties: None,
+                    required: None,
+                    r#type: "object".to_string(),
+                },
+                name: "ping".to_string(),
+                output_schema: None,
+                title: None,
+            },
+        );
+
+        let auth_statuses: HashMap<String, McpAuthStatus> = HashMap::new();
+        let cell = new_mcp_tools_output(
+            &config,
+            tools,
+            HashMap::new(),
+            HashMap::new(),
+            &auth_statuses,
+        );
+        let rendered = render_lines(&cell.display_lines(120)).join("\n");
+
+        insta::assert_snapshot!(rendered);
+    }
+
     #[test]
     fn empty_agent_message_cell_transcript() {
         let cell = AgentMessageCell::new(vec![Line::default()], false);

codex-rs/tui/src/snapshots/codex_tui__history_cell__tests__mcp_tools_output_masks_sensitive_values.snap

@@ -0,0 +1,27 @@
+---
+source: tui/src/history_cell.rs
+assertion_line: 1540
+expression: rendered
+---
+/mcp
+
+🔌  MCP Tools
+
+  • docs
+    • Status: enabled
+    • Auth: Unsupported
+    • Command: docs-server
+    • Env: TOKEN=*****, APP_TOKEN=*****
+    • Tools: list
+    • Resources: (none)
+    • Resource templates: (none)
+
+  • http
+    • Status: enabled
+    • Auth: Unsupported
+    • URL: https://example.com/mcp
+    • HTTP headers: Authorization=*****
+    • Env HTTP headers: X-API-Key=API_KEY_ENV
+    • Tools: ping
+    • Resources: (none)
+    • Resource templates: (none)