fix: Per RFC 9728, enable dynamic discovery of OAuth endpoints in MCP using path-aware discovery

src/config/mcp_factory.rs

@@ -3,7 +3,7 @@ use crate::mcp::{
     spawn_mcp_server,
 };
 
-use anyhow::{Result, anyhow};
+use anyhow::Result;
 use parking_lot::Mutex;
 use std::collections::HashMap;
 use std::path::Path;
@@ -111,10 +111,10 @@ impl McpFactory {
             .await
             .map_err(|e| {
                 if is_auth_required_error(&e) {
-                    anyhow!(
+                    e.context(format!(
                         "MCP server '{name}' requires OAuth authentication. \
                          Run `coyote --auth-mcp {name}` or `.mcp auth {name}` in the REPL to authenticate."
-                    )
+                    ))
                 } else {
                     e
                 }

src/config/request_context.rs

@@ -1,3 +1,4 @@
+use super::agent::AgentConfig;
 use super::rag_cache::{RagCache, RagKey};
 use super::session::Session;
 use super::skill::{SKILL_SCAFFOLD, Skill};
@@ -20,7 +21,7 @@ use crate::function::{
 };
 use crate::mcp::{
     MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX, MCP_INVOKE_META_FUNCTION_NAME_PREFIX,
-    MCP_SEARCH_META_FUNCTION_NAME_PREFIX,
+    MCP_SEARCH_META_FUNCTION_NAME_PREFIX, is_auth_required_error,
 };
 use crate::rag::Rag;
 use crate::supervisor::Supervisor;
@@ -87,6 +88,37 @@ pub fn should_inject_skill_instructions(app: &AppConfig, policy: &SkillPolicy) -
     app.function_calling_support && policy.skills_enabled && !policy.compatible_enabled.is_empty()
 }
 
+fn print_asset_names(kind: &str, names: &[String]) -> Result<()> {
+    if names.is_empty() {
+        println!("No {kind} found.");
+        return Ok(());
+    }
+
+    let mut header: Vec<char> = kind.chars().collect();
+    header[0] = header[0].to_ascii_uppercase();
+    let header: String = header.into_iter().collect();
+
+    println!("{header}:");
+    for name in names {
+        println!("  • {name}");
+    }
+
+    Ok(())
+}
+
+fn complete_skills_with_descriptions(names: Vec<String>) -> Vec<(String, Option<String>)> {
+    names
+        .into_iter()
+        .map(|name| {
+            let description = Skill::load(&name)
+                .ok()
+                .map(|s| s.description().to_string())
+                .filter(|d| !d.is_empty());
+            (name, description)
+        })
+        .collect()
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum RenderMode {
     #[default]
@@ -999,6 +1031,273 @@ impl RequestContext {
         }
     }
 
+    fn concrete_tool_names(&self) -> Vec<String> {
+        self.tool_scope
+            .functions
+            .declarations()
+            .iter()
+            .filter(|v| {
+                !v.name.starts_with("user__")
+                    && !v.name.starts_with("mcp_")
+                    && !v.name.starts_with("todo__")
+                    && !v.name.starts_with("agent__")
+            })
+            .map(|v| v.name.clone())
+            .collect()
+    }
+
+    fn tool_list_covers(&self, list: &[String], name: &str) -> bool {
+        for item in list {
+            let item = item.trim();
+            if item == name {
+                return true;
+            }
+
+            if let Some(values) = self.app.config.mapping_tools.get(item)
+                && values.split(',').any(|v| v.trim() == name)
+            {
+                return true;
+            }
+        }
+
+        false
+    }
+
+    fn mcp_list_covers(&self, list: &[String], name: &str) -> bool {
+        for item in list {
+            let item = item.trim();
+            if item == name {
+                return true;
+            }
+
+            if let Some(values) = self.app.config.mapping_mcp_servers.get(item)
+                && values.split(',').any(|v| v.trim() == name)
+            {
+                return true;
+            }
+        }
+
+        false
+    }
+
+    fn write_layer_label(&self) -> &'static str {
+        if self.session.is_some() {
+            "session"
+        } else if self.agent.is_some() {
+            "agent"
+        } else if self.role.is_some() {
+            "role"
+        } else {
+            "global, in-memory"
+        }
+    }
+
+    pub fn toggle_tool(&mut self, action: &str, name: &str) -> Result<()> {
+        let name = name.trim();
+        let enable = match action {
+            "enable" => true,
+            "disable" => false,
+            _ => bail!("Unknown action '{action}'. Usage: .tool <enable|disable> <name>"),
+        };
+
+        if self.session.is_none() && self.agent.is_some() {
+            bail!(
+                "Cannot adjust tools for an agent outside a session; start a session first with `.session`"
+            );
+        }
+
+        let pool = self.concrete_tool_names();
+        let is_alias = self.app.config.mapping_tools.contains_key(name);
+        if !pool.iter().any(|v| v == name) && !is_alias {
+            bail!("Unknown tool '{name}'. Run `.list tools` to see what's available");
+        }
+
+        let current: Option<Vec<String>> = if let Some(session) = &self.session {
+            session.enabled_tools()
+        } else if let Some(role) = &self.role {
+            role.enabled_tools()
+        } else {
+            self.app.config.enabled_tools.clone()
+        };
+        let layer = self.write_layer_label();
+
+        let new_list: Vec<String> = if enable {
+            match current {
+                Some(list) if list.iter().any(|s| s.trim() == "all") => {
+                    println!("Tool '{name}' is already enabled ('all' is set).");
+                    return Ok(());
+                }
+                Some(list) if self.tool_list_covers(&list, name) => {
+                    println!("Tool '{name}' is already enabled.");
+                    return Ok(());
+                }
+                Some(mut list) => {
+                    list.push(name.to_string());
+                    list
+                }
+                None => vec![name.to_string()],
+            }
+        } else {
+            match current {
+                None => {
+                    println!("No tools are enabled in this context; nothing to disable.");
+                    return Ok(());
+                }
+                Some(list) if list.is_empty() => {
+                    println!("No tools are enabled in this context; nothing to disable.");
+                    return Ok(());
+                }
+                Some(list) if list.iter().any(|s| s.trim() == "all") => {
+                    let mut materialized = pool;
+                    materialized.retain(|v| v != name);
+                    println!(
+                        "Note: expanded 'all' into {} concrete tools.",
+                        materialized.len()
+                    );
+                    materialized
+                }
+                Some(mut list) => {
+                    if list.iter().any(|s| s.trim() == name) {
+                        list.retain(|s| s.trim() != name);
+                        list
+                    } else if self.tool_list_covers(&list, name) {
+                        bail!(
+                            "Tool '{name}' is enabled via an alias in 'mapping_tools'. \
+                             Disable the alias instead, or set the list explicitly with `.set enabled_tools`."
+                        );
+                    } else {
+                        println!("Tool '{name}' is not enabled; nothing to do.");
+                        return Ok(());
+                    }
+                }
+            }
+        };
+
+        let new_list = Some(new_list);
+
+        if !self.set_enabled_tools_on_role_like(new_list.clone()) {
+            self.update_app_config(|app| app.enabled_tools = new_list.clone());
+        }
+
+        let verb = if enable { "Enabled" } else { "Disabled" };
+        println!("✓ {verb} tool '{name}' ({layer}).");
+
+        Ok(())
+    }
+
+    pub async fn toggle_mcp_server(
+        &mut self,
+        action: &str,
+        name: &str,
+        abort_signal: AbortSignal,
+    ) -> Result<()> {
+        let name = name.trim();
+        let enable = match action {
+            "enable" => true,
+            "disable" => false,
+            _ => bail!("Unknown action '{action}'. Usage: .mcp <enable|disable> <server_name>"),
+        };
+
+        if self.agent.is_some() {
+            bail!(
+                "Agent MCP servers are defined by the agent's config ('mcp_servers'); \
+                 edit the agent config with `.edit agent-config` instead."
+            );
+        }
+
+        let configured_keys: Vec<String> = match &self.app.mcp_config {
+            Some(mcp_config) if !mcp_config.mcp_servers.is_empty() => {
+                mcp_config.mcp_servers.keys().cloned().collect()
+            }
+            _ => bail!("No MCP servers are configured. Please configure MCP servers first."),
+        };
+        let is_alias = self.app.config.mapping_mcp_servers.contains_key(name);
+        if !configured_keys.iter().any(|v| v == name) && !is_alias {
+            bail!(
+                "MCP server '{name}' is not configured. Run `.list mcp-servers` to see what's available"
+            );
+        }
+
+        let current: Option<Vec<String>> = if let Some(session) = &self.session {
+            session.enabled_mcp_servers()
+        } else if let Some(role) = &self.role {
+            role.enabled_mcp_servers()
+        } else {
+            self.app.config.enabled_mcp_servers.clone()
+        };
+        let layer = self.write_layer_label();
+
+        let new_list: Vec<String> = if enable {
+            match current {
+                Some(list) if list.iter().any(|s| s.trim() == "all") => {
+                    println!("MCP server '{name}' is already enabled ('all' is set).");
+                    return Ok(());
+                }
+                Some(list) if self.mcp_list_covers(&list, name) => {
+                    println!("MCP server '{name}' is already enabled.");
+                    return Ok(());
+                }
+                Some(mut list) => {
+                    list.push(name.to_string());
+                    list
+                }
+                None => vec![name.to_string()],
+            }
+        } else {
+            match current {
+                None => {
+                    println!("No MCP servers are enabled in this context; nothing to disable.");
+                    return Ok(());
+                }
+                Some(list) if list.is_empty() => {
+                    println!("No MCP servers are enabled in this context; nothing to disable.");
+                    return Ok(());
+                }
+                Some(list) if list.iter().any(|s| s.trim() == "all") => {
+                    let mut materialized = configured_keys;
+                    materialized.retain(|v| v != name);
+                    materialized
+                }
+                Some(mut list) => {
+                    if list.iter().any(|s| s.trim() == name) {
+                        list.retain(|s| s.trim() != name);
+                        list
+                    } else if self.mcp_list_covers(&list, name) {
+                        bail!(
+                            "MCP server '{name}' is enabled via an alias in 'mapping_mcp_servers'. \
+                             Disable the alias instead, or set the list explicitly with `.set enabled_mcp_servers`."
+                        );
+                    } else {
+                        println!("MCP server '{name}' is not enabled; nothing to do.");
+                        return Ok(());
+                    }
+                }
+            }
+        };
+
+        if !enable && self.skill_registry.loaded_mcp_servers().contains(name) {
+            println!(
+                "Note: '{name}' is granted by a loaded skill and will keep running until that skill is unloaded."
+            );
+        }
+
+        let new_list = Some(new_list);
+        if !self.set_enabled_mcp_servers_on_role_like(new_list.clone()) {
+            self.update_app_config(|app| app.enabled_mcp_servers = new_list.clone());
+        }
+
+        if self.app.config.mcp_server_support {
+            let app = Arc::clone(&self.app.config);
+            self.bootstrap_tools(app.as_ref(), true, abort_signal)
+                .await?;
+        }
+
+        let verb = if enable { "Enabled" } else { "Disabled" };
+        println!("✓ {verb} MCP server '{name}' ({layer}).");
+
+        Ok(())
+    }
+
     pub fn set_save_session_on_session(&mut self, value: Option<bool>) -> bool {
         match self.session.as_mut() {
             Some(session) => {
@@ -1911,6 +2210,127 @@ impl RequestContext {
         Ok(())
     }
 
+    pub fn list_assets(&self, kind: &str) -> Result<()> {
+        match kind {
+            "roles" => print_asset_names("roles", &paths::list_roles(true)),
+            "sessions" => print_asset_names("sessions", &self.list_sessions()),
+            "rags" => print_asset_names("RAGs", &paths::list_rags()),
+            "macros" => print_asset_names("macros", &paths::list_macros()),
+            "agents" => {
+                let names = list_agents();
+                if names.is_empty() {
+                    println!("No agents found.");
+                    return Ok(());
+                }
+
+                println!("Agents:");
+                for name in names {
+                    let description = AgentConfig::load(&paths::agent_config_file(&name))
+                        .ok()
+                        .map(|c| c.description)
+                        .filter(|d| !d.is_empty());
+                    match description {
+                        Some(description) => println!("  • {name} — {description}"),
+                        None => println!("  • {name}"),
+                    }
+                }
+
+                Ok(())
+            }
+            "skills" => {
+                let policy = SkillPolicy::effective(
+                    &self.app.config,
+                    self.role.as_ref(),
+                    self.agent.as_ref(),
+                    self.session.as_ref(),
+                )?;
+
+                if !policy.skills_enabled {
+                    bail!("Skills are disabled in this context");
+                }
+
+                let visible_names: Vec<String> = match self.app.config.visible_skills.as_deref() {
+                    Some(list) => list.to_vec(),
+                    None => paths::list_skills(),
+                };
+
+                let mut entries = Vec::new();
+                for name in visible_names {
+                    if !policy.compatible_enabled.contains(&name) {
+                        continue;
+                    }
+                    let skill = match Skill::load(&name) {
+                        Ok(s) => s,
+                        Err(e) => {
+                            warn!("Failed to open skill '{name}' for listing: {e}");
+                            continue;
+                        }
+                    };
+
+                    let loaded = self.skill_registry.is_loaded(skill.name());
+                    entries.push((
+                        skill.name().to_string(),
+                        skill.description().to_string(),
+                        loaded,
+                    ));
+                }
+
+                if entries.is_empty() {
+                    println!("No skills found.");
+                    return Ok(());
+                }
+
+                println!("Skills:");
+                for (name, description, loaded) in entries {
+                    let marker = if loaded { " (loaded)" } else { "" };
+                    println!("  • {name}{marker} — {description}");
+                }
+
+                Ok(())
+            }
+            "tools" => {
+                let mut names: Vec<String> = self
+                    .tool_scope
+                    .functions
+                    .declarations()
+                    .iter()
+                    .filter(|v| {
+                        !v.name.starts_with("user__")
+                            && !v.name.starts_with("mcp_")
+                            && !v.name.starts_with("todo__")
+                            && !v.name.starts_with("agent__")
+                    })
+                    .map(|v| v.name.clone())
+                    .collect();
+                names.extend(self.app.config.mapping_tools.keys().map(|v| v.to_string()));
+                names.sort_unstable();
+                names.dedup();
+
+                print_asset_names("tools", &names)
+            }
+            "mcp-servers" => {
+                let mut names: Vec<String> = vec![];
+                if let Some(mcp_config) = &self.app.mcp_config {
+                    names.extend(mcp_config.mcp_servers.keys().map(|v| v.to_string()));
+                }
+                names.extend(
+                    self.app
+                        .config
+                        .mapping_mcp_servers
+                        .keys()
+                        .map(|v| v.to_string()),
+                );
+                names.sort_unstable();
+                names.dedup();
+
+                print_asset_names("MCP servers", &names)
+            }
+            _ => bail!(
+                "Unknown kind '{kind}'. Valid kinds: roles, sessions, agents, rags, macros, skills, tools, mcp-servers"
+            ),
+        }
+    }
+
     pub fn delete(&self, kind: &str) -> Result<()> {
         let (dir, file_ext) = match kind {
             "role" => (paths::roles_dir(), Some(".md")),
@@ -2327,7 +2747,16 @@ impl RequestContext {
                     }
                 }
                 ".rag" => super::map_completion_values(paths::list_rags()),
-                ".agent" => super::map_completion_values(list_agents()),
+                ".agent" => list_agents()
+                    .into_iter()
+                    .map(|name| {
+                        let description = AgentConfig::load(&paths::agent_config_file(&name))
+                            .ok()
+                            .map(|c| c.description)
+                            .filter(|d| !d.is_empty());
+                        (name, description)
+                    })
+                    .collect(),
                 ".install" => {
                     let mut values: Vec<String> =
                         AssetCategory::NAMES.iter().map(|s| s.to_string()).collect();
@@ -2391,6 +2820,16 @@ impl RequestContext {
                     "skill",
                     "agent-data",
                 ]),
+                ".list" => super::map_completion_values(vec![
+                    "roles",
+                    "sessions",
+                    "agents",
+                    "rags",
+                    "macros",
+                    "skills",
+                    "tools",
+                    "mcp-servers",
+                ]),
                 ".vault" => {
                     let mut values = vec!["add", "get", "update", "delete", "list"];
                     values.sort_unstable();
@@ -2412,12 +2851,91 @@ impl RequestContext {
                         .collect(),
                 );
             }
+        } else if cmd == ".mcp"
+            && (args.first() == Some(&"enable") || args.first() == Some(&"disable"))
+            && args.len() == 2
+        {
+            let current = if let Some(session) = &self.session {
+                session.enabled_mcp_servers()
+            } else if let Some(role) = &self.role {
+                role.enabled_mcp_servers()
+            } else {
+                self.app.config.enabled_mcp_servers.clone()
+            }
+            .unwrap_or_default();
+            let has_all = current.iter().any(|s| s.trim() == "all");
+
+            let candidates: Vec<String> = if args.first() == Some(&"enable") {
+                if has_all {
+                    vec![]
+                } else {
+                    let mut candidates: Vec<String> = vec![];
+                    if let Some(mcp_config) = &self.app.mcp_config {
+                        candidates.extend(mcp_config.mcp_servers.keys().cloned());
+                    }
+                    candidates.extend(self.app.config.mapping_mcp_servers.keys().cloned());
+                    candidates.sort_unstable();
+                    candidates.dedup();
+                    candidates.retain(|v| !self.mcp_list_covers(&current, v));
+
+                    candidates
+                }
+            } else if has_all {
+                self.app
+                    .mcp_config
+                    .as_ref()
+                    .map(|c| c.mcp_servers.keys().cloned().collect())
+                    .unwrap_or_default()
+            } else {
+                current
+                    .iter()
+                    .map(|s| s.trim().to_string())
+                    .filter(|s| s != "all" && !s.is_empty())
+                    .collect()
+            };
+            values = super::map_completion_values(candidates);
+        } else if cmd == ".tool"
+            && (args.first() == Some(&"enable") || args.first() == Some(&"disable"))
+            && args.len() == 2
+        {
+            let current = if let Some(session) = &self.session {
+                session.enabled_tools()
+            } else if let Some(role) = &self.role {
+                role.enabled_tools()
+            } else {
+                self.app.config.enabled_tools.clone()
+            }
+            .unwrap_or_default();
+            let has_all = current.iter().any(|s| s.trim() == "all");
+
+            let candidates: Vec<String> = if args.first() == Some(&"enable") {
+                if has_all {
+                    vec![]
+                } else {
+                    let mut candidates = self.concrete_tool_names();
+                    candidates.extend(self.app.config.mapping_tools.keys().cloned());
+                    candidates.sort_unstable();
+                    candidates.dedup();
+                    candidates.retain(|v| !self.tool_list_covers(&current, v));
+
+                    candidates
+                }
+            } else if has_all {
+                self.concrete_tool_names()
+            } else {
+                current
+                    .iter()
+                    .map(|s| s.trim().to_string())
+                    .filter(|s| s != "all" && !s.is_empty())
+                    .collect()
+            };
+            values = super::map_completion_values(candidates);
         } else if (cmd == ".edit" && args.first() == Some(&"skill") && args.len() == 2)
             || (cmd == ".skill" && args.first() == Some(&"load") && args.len() == 2)
         {
-            values = super::map_completion_values(paths::list_skills());
+            values = complete_skills_with_descriptions(paths::list_skills());
         } else if cmd == ".skill" && args.first() == Some(&"unload") && args.len() == 2 {
-            values = super::map_completion_values(self.skill_registry.loaded_names());
+            values = complete_skills_with_descriptions(self.skill_registry.loaded_names());
         } else if cmd == ".install" && args.first() == Some(&"remote") && args.len() >= 2 {
             let prev = args.get(args.len() - 2).copied().unwrap_or("");
             if prev == "--filter" {
@@ -2643,18 +3161,25 @@ impl RequestContext {
                 let app_ref = &self.app;
                 let acquire_all = async {
                     let mut handles = Vec::new();
+                    let mut auth_required = Vec::new();
                     for id in &server_ids {
                         if let Some(spec) = mcp_config.mcp_servers.get(id) {
-                            let handle = app_ref
+                            match app_ref
                                 .mcp_factory
                                 .acquire(id, spec, app_ref.mcp_log_path.as_deref())
-                                .await?;
-                            handles.push((id.clone(), handle));
+                                .await
+                            {
+                                Ok(handle) => handles.push((id.clone(), handle)),
+                                Err(e) if is_auth_required_error(&e) => {
+                                    auth_required.push(id.clone())
+                                }
+                                Err(e) => return Err(e),
+                            }
                         }
                     }
-                    Ok::<_, Error>(handles)
+                    Ok::<_, Error>((handles, auth_required))
                 };
-                let handles = abortable_run_with_spinner(
+                let (handles, auth_required) = abortable_run_with_spinner(
                     acquire_all,
                     "Loading MCP servers",
                     abort_signal.clone(),
@@ -2663,6 +3188,12 @@ impl RequestContext {
                 for (id, handle) in handles {
                     mcp_runtime.insert(id, handle);
                 }
+                for id in auth_required {
+                    eprintln!(
+                        "Warning: MCP server '{id}' requires OAuth authentication and was not started. \
+                         Run `.mcp auth {id}` (or `coyote --auth-mcp {id}`) to authenticate and attach it."
+                    );
+                }
             }
         }
 
@@ -2763,9 +3294,18 @@ impl RequestContext {
                 );
             }
         }
+        let prev_role = self.role.clone();
+        let prev_session = self.session.clone();
         self.use_role_obj(role)?;
-        self.rebuild_tool_scope(app, mcp_servers, abort_signal)
+        if let Err(e) = self
+            .rebuild_tool_scope(app, mcp_servers, abort_signal)
             .await
+        {
+            self.role = prev_role;
+            self.session = prev_session;
+            return Err(e);
+        }
+        Ok(())
     }
 
     pub async fn use_session(
@@ -3793,6 +4333,14 @@ mod tests {
     }
 
     fn app_state_with_mcp_config(mcp_server_support: bool, server_names: &[&str]) -> Arc<AppState> {
+        app_state_with_mcp_command(mcp_server_support, server_names, "echo")
+    }
+
+    fn app_state_with_mcp_command(
+        mcp_server_support: bool,
+        server_names: &[&str],
+        command: &str,
+    ) -> Arc<AppState> {
         let app_config = AppConfig {
             mcp_server_support,
             ..AppConfig::default()
@@ -3807,7 +4355,7 @@ mod tests {
                     name.to_string(),
                     McpServer {
                         transport_type: McpTransportType::Stdio,
-                        command: Some("echo".to_string()),
+                        command: Some(command.to_string()),
                         args: None,
                         env: None,
                         cwd: None,
@@ -3856,6 +4404,33 @@ mod tests {
         assert!(ctx.tool_scope.mcp_runtime.is_empty());
     }
 
+    #[test]
+    #[serial]
+    fn use_role_rolls_back_when_mcp_startup_fails() {
+        let _guard = TestConfigDirGuard::new();
+        let roles_dir = paths::roles_dir();
+        create_dir_all(&roles_dir).unwrap();
+        write(
+            roles_dir.join("broken_mcp.md"),
+            "---\nenabled_mcp_servers: failing\n---\nYou use MCP servers.",
+        )
+        .unwrap();
+
+        let app_state =
+            app_state_with_mcp_command(true, &["failing"], "/nonexistent/coyote-test-mcp-binary");
+        let mut ctx = RequestContext::new(app_state, WorkingMode::Cmd);
+        let app = ctx.app.config.clone();
+        let abort = utils::create_abort_signal();
+
+        let result = run_async(ctx.use_role(&app, "broken_mcp", abort));
+
+        assert!(result.is_err());
+        assert!(
+            ctx.role.is_none(),
+            "role must be rolled back when MCP startup fails"
+        );
+    }
+
     #[test]
     #[serial]
     fn rebuild_tool_scope_no_enabled_servers_yields_empty_runtime() {

src/graph/structured.rs

@@ -33,7 +33,7 @@ async fn extract_via_extractor(
     parent_ctx: &mut RequestContext,
     is_repair: bool,
 ) -> Result<Value> {
-    let role = build_extractor_role()?;
+    let role = build_extractor_role(parent_ctx);
     let prompt = build_extractor_prompt(raw, schema, is_repair);
 
     let saved_role = parent_ctx.role.clone();
@@ -53,11 +53,12 @@ async fn extract_via_extractor(
     }
 }
 
-fn build_extractor_role() -> Result<Role> {
+fn build_extractor_role(ctx: &RequestContext) -> Role {
     let mut role = Role::new(EXTRACTOR_ROLE_NAME, EXTRACTOR_ROLE_PROMPT);
+    role.set_model(ctx.current_model().clone());
     role.set_enabled_tools(Some(Vec::new()));
     role.set_enabled_mcp_servers(Some(Vec::new()));
-    Ok(role)
+    role
 }
 
 fn build_extractor_prompt(raw: &str, schema: &Value, is_repair: bool) -> String {
@@ -107,8 +108,14 @@ fn strip_code_fences(s: &str) -> &str {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::client::Model;
+    use crate::config::{AppState, WorkingMode};
     use serde_json::json;
 
+    fn make_ctx() -> RequestContext {
+        RequestContext::new(Arc::new(AppState::test_default()), WorkingMode::Cmd)
+    }
+
     #[test]
     fn try_parse_json_accepts_plain_object() {
         let v = try_parse_json(r#"{"a": 1}"#).unwrap();
@@ -181,9 +188,23 @@ mod tests {
 
     #[test]
     fn build_extractor_role_disables_tools_and_mcp() {
-        let role = build_extractor_role().expect("builtin role must exist");
+        let ctx = make_ctx();
+
+        let role = build_extractor_role(&ctx);
 
         assert_eq!(role.enabled_tools().as_deref(), Some([].as_slice()));
         assert_eq!(role.enabled_mcp_servers().as_deref(), Some([].as_slice()));
     }
+
+    #[test]
+    fn build_extractor_role_uses_parent_context_model() {
+        let mut ctx = make_ctx();
+        let mut parent_role = Role::new("parent", "parent prompt");
+        parent_role.set_model(Model::new("client-x", "model-y"));
+        ctx.role = Some(parent_role);
+
+        let role = build_extractor_role(&ctx);
+
+        assert_eq!(role.model().id(), "client-x:model-y");
+    }
 }

src/mcp/mod.rs

@@ -1061,4 +1061,14 @@ mod tests {
 
         assert!(!is_auth_required_error(&e));
     }
+
+    #[test]
+    fn is_auth_required_error_survives_context_wrapping() {
+        let e = anyhow!("Auth required, when send initialize request").context(
+            "MCP server 'github' requires OAuth authentication. \
+             Run `coyote --auth-mcp github` or `.mcp auth github` in the REPL to authenticate.",
+        );
+
+        assert!(is_auth_required_error(&e));
+    }
 }

src/mcp/oauth.rs

@@ -14,6 +14,8 @@ use url::Url;
 struct ProtectedResourceMetadata {
     #[serde(default)]
     authorization_servers: Vec<String>,
+    #[serde(default)]
+    scopes_supported: Vec<String>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -187,46 +189,122 @@ async fn register_client(endpoint: &str, redirect_uri: &str) -> Result<String> {
 }
 
 async fn discover_oauth_metadata(server_url: &str) -> Result<OAuthServerMetadata> {
-    let base = extract_base_url(server_url)?;
     let client = Client::new();
+    let mut tried: Vec<String> = Vec::new();
 
-    // RFC 9728: try protected resource metadata first; it points to the auth server
-    let pr_url = format!("{base}/.well-known/oauth-protected-resource");
-    if let Ok(resp) = client.get(&pr_url).send().await
-        && resp.status().is_success()
-        && let Ok(pr) = resp.json::<ProtectedResourceMetadata>().await
-        && let Some(auth_server) = pr.authorization_servers.first()
-    {
-        let as_url = format!("{auth_server}/.well-known/oauth-authorization-server");
-        if let Ok(resp) = client.get(&as_url).send().await
-            && resp.status().is_success()
-            && let Ok(meta) = resp.json::<OAuthServerMetadata>().await
-        {
-            return Ok(meta);
+    // RFC 9728 @ 5.1: an unauthenticated request should yield a 401 whose
+    // WWW-Authenticate challenge advertises the protected resource metadata URL.
+    let mut pr_urls = Vec::new();
+    if let Some(url) = probe_resource_metadata_url(&client, server_url).await {
+        pr_urls.push(url);
+    }
+
+    // RFC 9728 @ 3.1: path-aware well-known URL, then root as legacy fallback.
+    pr_urls.extend(well_known_urls(server_url, "oauth-protected-resource")?);
+    pr_urls.dedup();
+
+    for pr_url in &pr_urls {
+        tried.push(pr_url.clone());
+        let Ok(resp) = client.get(pr_url).send().await else {
+            continue;
+        };
+        if !resp.status().is_success() {
+            continue;
+        }
+        let Ok(pr) = resp.json::<ProtectedResourceMetadata>().await else {
+            continue;
+        };
+        let Some(issuer) = pr.authorization_servers.first() else {
+            continue;
+        };
+        // RFC 8414 @ 3.1: for issuers with a path component the well-known
+        // segment is inserted BEFORE the path (with the legacy appended form
+        // and root as fallbacks).
+        for as_url in well_known_urls(issuer, "oauth-authorization-server")? {
+            tried.push(as_url.clone());
+            if let Ok(resp) = client.get(&as_url).send().await
+                && resp.status().is_success()
+                && let Ok(mut meta) = resp.json::<OAuthServerMetadata>().await
+            {
+                // Some auth servers (e.g. GitHub) omit scopes_supported from
+                // their metadata; fall back to the resource's advertised scopes.
+                if meta.scopes_supported.is_empty() {
+                    meta.scopes_supported = pr.scopes_supported.clone();
+                }
+                return Ok(meta);
+            }
         }
     }
 
-    let as_url = format!("{base}/.well-known/oauth-authorization-server");
-    let resp = client
-        .get(&as_url)
-        .send()
-        .await
-        .with_context(|| format!("Failed to reach {as_url}"))?;
-
-    if resp.status().is_success() {
-        return resp
-            .json::<OAuthServerMetadata>()
-            .await
-            .with_context(|| format!("Failed to parse OAuth metadata from {as_url}"));
+    // Last resort: the MCP server itself may host authorization server metadata.
+    for as_url in well_known_urls(server_url, "oauth-authorization-server")? {
+        tried.push(as_url.clone());
+        if let Ok(resp) = client.get(&as_url).send().await
+            && resp.status().is_success()
+        {
+            return resp
+                .json::<OAuthServerMetadata>()
+                .await
+                .with_context(|| format!("Failed to parse OAuth metadata from {as_url}"));
+        }
     }
 
     Err(anyhow!(
         "Could not discover OAuth metadata for '{server_url}'.\n\
-         Tried:\n  {pr_url}\n  {as_url}\n\
-         Ensure the server supports MCP OAuth discovery, or consult its documentation."
+         Tried:\n  {}\n\
+         Ensure the server supports MCP OAuth discovery, or consult its documentation.",
+        tried.join("\n  ")
     ))
 }
 
+/// Probes the MCP server with an unauthenticated request and extracts the
+/// `resource_metadata` URL from the 401 `WWW-Authenticate` challenge (RFC 9728 @ 5.1).
+async fn probe_resource_metadata_url(client: &Client, server_url: &str) -> Option<String> {
+    let resp = client.get(server_url).send().await.ok()?;
+    let header = resp.headers().get(reqwest::header::WWW_AUTHENTICATE)?;
+
+    parse_resource_metadata(header.to_str().ok()?)
+}
+
+/// Extracts the `resource_metadata` parameter value from a `WWW-Authenticate`
+/// challenge, e.g. `Bearer error="...", resource_metadata="https://..."`.
+fn parse_resource_metadata(challenge: &str) -> Option<String> {
+    let (_, rest) = challenge.split_once("resource_metadata=")?;
+    let rest = rest.trim_start();
+    let value = if let Some(stripped) = rest.strip_prefix('"') {
+        stripped.split('"').next()?
+    } else {
+        rest.split([',', ' ']).next()?
+    };
+
+    if value.is_empty() {
+        None
+    } else {
+        Some(value.to_string())
+    }
+}
+
+/// Builds candidate well-known metadata URLs for `url`, ordered by spec preference:
+/// 1. Path-aware (RFC 8414 @ 3.1 / RFC 9728 @ 3.1): `{origin}/.well-known/{suffix}{path}`
+/// 2. Legacy appended form: `{url}/.well-known/{suffix}`
+/// 3. Root: `{origin}/.well-known/{suffix}`
+///
+/// URLs without a path component yield only the root form.
+fn well_known_urls(url: &str, suffix: &str) -> Result<Vec<String>> {
+    let parsed = Url::parse(url).with_context(|| format!("Invalid URL: {url}"))?;
+    let origin = extract_base_url(url)?;
+    let path = parsed.path().trim_end_matches('/');
+
+    let mut urls = Vec::new();
+    if !path.is_empty() && path != "/" {
+        urls.push(format!("{origin}/.well-known/{suffix}{path}"));
+        urls.push(format!("{origin}{path}/.well-known/{suffix}"));
+    }
+    urls.push(format!("{origin}/.well-known/{suffix}"));
+
+    Ok(urls)
+}
+
 fn extract_base_url(url: &str) -> Result<String> {
     let parsed = Url::parse(url).with_context(|| format!("Invalid URL: {url}"))?;
     let scheme = parsed.scheme();
@@ -296,6 +374,101 @@ mod tests {
         assert!(extract_base_url("not-a-url").is_err());
     }
 
+    #[test]
+    fn well_known_urls_path_aware_first_for_url_with_path() {
+        let urls = well_known_urls(
+            "https://api.githubcopilot.com/mcp",
+            "oauth-protected-resource",
+        )
+        .unwrap();
+
+        assert_eq!(
+            urls,
+            vec![
+                "https://api.githubcopilot.com/.well-known/oauth-protected-resource/mcp",
+                "https://api.githubcopilot.com/mcp/.well-known/oauth-protected-resource",
+                "https://api.githubcopilot.com/.well-known/oauth-protected-resource",
+            ]
+        );
+    }
+
+    #[test]
+    fn well_known_urls_inserts_before_issuer_path() {
+        let urls = well_known_urls(
+            "https://github.com/login/oauth",
+            "oauth-authorization-server",
+        )
+        .unwrap();
+
+        assert_eq!(
+            urls[0],
+            "https://github.com/.well-known/oauth-authorization-server/login/oauth"
+        );
+    }
+
+    #[test]
+    fn well_known_urls_root_only_for_url_without_path() {
+        let urls = well_known_urls("https://mcp.notion.com", "oauth-authorization-server").unwrap();
+
+        assert_eq!(
+            urls,
+            vec!["https://mcp.notion.com/.well-known/oauth-authorization-server"]
+        );
+    }
+
+    #[test]
+    fn well_known_urls_ignores_trailing_slash() {
+        let urls = well_known_urls(
+            "https://api.githubcopilot.com/mcp/",
+            "oauth-protected-resource",
+        )
+        .unwrap();
+
+        assert_eq!(
+            urls[0],
+            "https://api.githubcopilot.com/.well-known/oauth-protected-resource/mcp"
+        );
+    }
+
+    #[test]
+    fn parse_resource_metadata_extracts_quoted_url() {
+        let challenge = r#"Bearer error="invalid_request", error_description="No access token was provided in this request", resource_metadata="https://api.githubcopilot.com/.well-known/oauth-protected-resource/mcp""#;
+
+        let url = parse_resource_metadata(challenge);
+
+        assert_eq!(
+            url,
+            Some(
+                "https://api.githubcopilot.com/.well-known/oauth-protected-resource/mcp"
+                    .to_string()
+            )
+        );
+    }
+
+    #[test]
+    fn parse_resource_metadata_extracts_unquoted_url() {
+        let challenge = "Bearer resource_metadata=https://example.com/.well-known/oauth-protected-resource/mcp, error=\"invalid_token\"";
+
+        let url = parse_resource_metadata(challenge);
+
+        assert_eq!(
+            url,
+            Some("https://example.com/.well-known/oauth-protected-resource/mcp".to_string())
+        );
+    }
+
+    #[test]
+    fn parse_resource_metadata_returns_none_when_absent() {
+        assert_eq!(
+            parse_resource_metadata(r#"Bearer error="invalid_token""#),
+            None
+        );
+        assert_eq!(
+            parse_resource_metadata(r#"Bearer resource_metadata="""#),
+            None
+        );
+    }
+
     #[test]
     #[serial]
     fn registered_client_id_roundtrip() {

src/repl/mod.rs

@@ -52,7 +52,7 @@ pub const DEFAULT_CONTINUATION_PROMPT: &str = indoc! {"
     4. Continue with the next pending item now. Call tools immediately."
 };
 
-static REPL_COMMANDS: LazyLock<[ReplCommand; 52]> = LazyLock::new(|| {
+static REPL_COMMANDS: LazyLock<[ReplCommand; 57]> = LazyLock::new(|| {
     [
         ReplCommand::new(".help", "Show this help guide", AssertState::pass()),
         ReplCommand::new(".info", "Show system info", AssertState::pass()),
@@ -71,6 +71,26 @@ static REPL_COMMANDS: LazyLock<[ReplCommand; 52]> = LazyLock::new(|| {
             "Authenticate with an MCP server via OAuth",
             AssertState::pass(),
         ),
+        ReplCommand::new(
+            ".mcp enable",
+            "Enable a single MCP server in the current context",
+            AssertState::pass(),
+        ),
+        ReplCommand::new(
+            ".mcp disable",
+            "Disable a single MCP server in the current context",
+            AssertState::pass(),
+        ),
+        ReplCommand::new(
+            ".tool enable",
+            "Enable a single tool in the current context",
+            AssertState::True(StateFlags::FUNCTION_CALLING),
+        ),
+        ReplCommand::new(
+            ".tool disable",
+            "Disable a single tool in the current context",
+            AssertState::True(StateFlags::FUNCTION_CALLING),
+        ),
         ReplCommand::new(
             ".edit config",
             "Modify configuration file",
@@ -269,6 +289,11 @@ static REPL_COMMANDS: LazyLock<[ReplCommand; 52]> = LazyLock::new(|| {
             "Delete roles, sessions, RAGs, or agents",
             AssertState::pass(),
         ),
+        ReplCommand::new(
+            ".list",
+            "List roles, sessions, agents, RAGs, macros, skills, tools, or MCP servers",
+            AssertState::pass(),
+        ),
         ReplCommand::new(
             ".vault",
             "View or modify the Coyote vault",
@@ -673,14 +698,69 @@ pub async fn run_repl_command(
                                         )
                                         .await?;
                                         println!("Authentication saved.");
+                                        if ctx.app.config.mcp_server_support {
+                                            let app = Arc::clone(&ctx.app.config);
+                                            ctx.bootstrap_tools(
+                                                app.as_ref(),
+                                                true,
+                                                abort_signal.clone(),
+                                            )
+                                            .await?;
+                                            if ctx.tool_scope.mcp_runtime.get(server_name).is_some()
+                                            {
+                                                println!(
+                                                    "✓ MCP server '{server_name}' started and attached to the current context."
+                                                );
+                                            } else {
+                                                println!(
+                                                    "MCP server '{server_name}' is not enabled in the current context. \
+                                                     Run `.mcp enable {server_name}` to attach it."
+                                                );
+                                            }
+                                        }
                                     }
                                 }
                             }
                         }
+                        "enable" | "disable" => {
+                            if rest.is_empty() {
+                                println!("Usage: .mcp {sub} <server_name>");
+                            } else {
+                                ctx.toggle_mcp_server(sub, rest, abort_signal.clone())
+                                    .await?;
+                            }
+                        }
                         _ => unknown_command()?,
                     }
                 }
-                None => println!("Usage: .mcp auth <server_name>"),
+                None => println!(
+                    r#"Usage:
+    .mcp auth <server_name>         # Authenticate with an MCP server via OAuth
+    .mcp enable <server_name>       # Enable a single MCP server in the current context
+    .mcp disable <server_name>      # Disable a single MCP server in the current context"#
+                ),
+            },
+            ".tool" => match args {
+                Some(args) => {
+                    let mut parts = args.splitn(2, char::is_whitespace);
+                    let sub = parts.next().unwrap_or("").trim();
+                    let rest = parts.next().map(str::trim).unwrap_or("");
+                    match sub {
+                        "enable" | "disable" => {
+                            if rest.is_empty() {
+                                println!("Usage: .tool {sub} <name>");
+                            } else {
+                                ctx.toggle_tool(sub, rest)?;
+                            }
+                        }
+                        _ => unknown_command()?,
+                    }
+                }
+                None => println!(
+                    r#"Usage:
+    .tool enable <name>             # Enable a single tool in the current context
+    .tool disable <name>            # Disable a single tool in the current context"#
+                ),
             },
             ".prompt" => match args {
                 Some(text) => {
@@ -1092,6 +1172,16 @@ pub async fn run_repl_command(
                     println!("Usage: .delete <role|session|rag|macro|skill|agent-data>")
                 }
             },
+            ".list" => match args {
+                Some(args) => {
+                    ctx.list_assets(args.trim())?;
+                }
+                _ => {
+                    println!(
+                        "Usage: .list <roles|sessions|agents|rags|macros|skills|tools|mcp-servers>"
+                    )
+                }
+            },
             ".copy" => {
                 let output = match ctx
                     .last_message
@@ -1614,8 +1704,8 @@ mod tests {
     }
 
     #[test]
-    fn repl_commands_has_52_entries() {
-        assert_eq!(REPL_COMMANDS.len(), 52);
+    fn repl_commands_has_57_entries() {
+        assert_eq!(REPL_COMMANDS.len(), 57);
     }
 
     #[test]