feat: Created the --auth-mcp CLI flag to let users auth with remote MCP servers without needing to be in the REPL

src/cli/completer.rs

@@ -5,9 +5,9 @@ use crate::utils::list_file_names;
 use crate::vault::Vault;
 use clap_complete::{CompletionCandidate, Shell, generate};
 use clap_complete_nushell::Nushell;
-use std::env;
 use std::ffi::OsStr;
 use std::io;
+use std::{env, fs};
 
 const COYOTE_CLI_NAME: &str = "coyote";
 
@@ -134,6 +134,34 @@ pub(super) fn session_completer(current: &OsStr) -> Vec<CompletionCandidate> {
         .collect()
 }
 
+pub(super) fn mcp_server_completer(current: &OsStr) -> Vec<CompletionCandidate> {
+    let cur = current.to_string_lossy();
+    let content = match fs::read_to_string(paths::mcp_config_file()) {
+        Ok(c) => c,
+        Err(_) => return vec![],
+    };
+    let json: serde_json::Value = match serde_json::from_str(&content) {
+        Ok(v) => v,
+        Err(_) => return vec![],
+    };
+    let servers = match json.get("mcpServers").and_then(|v| v.as_object()) {
+        Some(s) => s,
+        None => return vec![],
+    };
+
+    servers
+        .iter()
+        .filter(|(_, v)| {
+            v.get("type")
+                .and_then(|t| t.as_str())
+                .map(|t| t == "http" || t == "sse")
+                .unwrap_or(false)
+        })
+        .filter(|(k, _)| k.starts_with(&*cur))
+        .map(|(k, _)| CompletionCandidate::new(k))
+        .collect()
+}
+
 pub(super) fn secrets_completer(current: &OsStr) -> Vec<CompletionCandidate> {
     let cur = current.to_string_lossy();
     match load_app_config_for_completion() {

src/cli/mod.rs

@@ -1,8 +1,8 @@
 mod completer;
 
 use crate::cli::completer::{
-    ShellCompletion, agent_completer, macro_completer, model_completer, rag_completer,
+    ShellCompletion, agent_completer, macro_completer, mcp_server_completer, model_completer,
-    role_completer, secrets_completer, session_completer,
+    rag_completer, role_completer, secrets_completer, session_completer,
 };
 use crate::config::{AssetCategory, InstallFilter, MemoryScope};
 use anyhow::{Context, Result};
@@ -171,6 +171,9 @@ pub struct Cli {
     /// Authenticate with an LLM provider using OAuth (e.g., --authenticate client_name)
     #[arg(long, exclusive = true, value_name = "CLIENT_NAME")]
     pub authenticate: Option<Option<String>>,
+    /// Authenticate with an OAuth-protected remote MCP server (e.g., --auth-mcp server_name)
+    #[arg(long, exclusive = true, value_name = "SERVER_NAME", add = ArgValueCompleter::new(mcp_server_completer))]
+    pub auth_mcp: Option<String>,
     /// Generate static shell completion scripts
     #[arg(long, value_name = "SHELL", value_enum)]
     pub completions: Option<ShellCompletion>,

src/main.rs

@@ -28,11 +28,12 @@ use crate::config::{
     install_builtins, list_agents, load_env_file, macro_execute, sync_models,
 };
 use crate::function::supervisor::{GuardrailAction, check_pending_agents_guardrail};
+use crate::mcp::McpServersConfig;
 use crate::render::{prompt_theme, render_error};
 use crate::repl::Repl;
 use crate::utils::*;
-use crate::vault::Vault;
+use crate::vault::{Vault, interpolate_secrets};
-use anyhow::{Result, anyhow, bail};
+use anyhow::{Context, Result, anyhow, bail};
 use clap::{CommandFactory, Parser};
 use clap_complete::CompleteEnv;
 use client::ClientConfig;
@@ -120,6 +121,48 @@ async fn main() -> Result<()> {
         return Ok(());
     }
 
+    if let Some(server_name) = &cli.auth_mcp {
+        let cfg = Config::load_with_interpolation(true).await?;
+        let app_config = AppConfig::from_config(cfg)?;
+        let vault = Vault::init(&app_config)?;
+        let mcp_path = paths::mcp_config_file();
+        if !mcp_path.exists() {
+            bail!(
+                "No MCP configuration file found at '{}'",
+                mcp_path.display()
+            );
+        }
+
+        let raw = tokio::fs::read_to_string(&mcp_path)
+            .await
+            .with_context(|| format!("Failed to read MCP config at '{}'", mcp_path.display()))?;
+
+        let (content, missing) = interpolate_secrets(&raw, &vault)?;
+        if !missing.is_empty() {
+            bail!(
+                "MCP config references vault secrets that are missing: {:?}",
+                missing
+            );
+        }
+
+        let mcp_config: McpServersConfig =
+            serde_json::from_str(&content).context("Failed to parse MCP config file")?;
+        let spec = mcp_config
+            .mcp_servers
+            .get(server_name.as_str())
+            .ok_or_else(|| anyhow!("MCP server '{server_name}' not found in mcp.json"))?;
+        if !spec.is_remote() {
+            bail!(
+                "MCP server '{server_name}' is a stdio server; OAuth is only supported for http/sse servers"
+            );
+        }
+
+        let url = spec.url.as_deref().expect("validated: remote spec has url");
+        mcp::oauth::run_mcp_oauth_flow(server_name, url, spec.oauth_client_id.as_deref()).await?;
+
+        return Ok(());
+    }
+
     if vault_flags {
         let cfg = Config::load_with_interpolation(true).await?;
         let app_config = AppConfig::from_config(cfg)?;