refactor(registry): move MCP servers from code to JSON manifests (#1144)

* refactor(registry): move MCP server entries from code to JSON manifests

Move 8 hardcoded MCP server RegistryEntry structs from
builtin_entries() into data-driven JSON files under
registry/mcp-servers/, matching the existing pattern used by
tools and channels. Exclude the GitHub MCP entry which conflicts
with the WASM GitHub tool's OAuth flow.

Extend ManifestKind with McpServer, make version/source optional
on ExtensionManifest (MCP servers don't need them), and add
url/auth fields for MCP-specific config. Update build.rs,
embedded catalog, catalog loader, installer, and CLI display
to handle the new kind and optional fields.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(registry): address PR review — add missing slack-mcp, remove .expect(), fix fmt

- Add missing slack-mcp.json (was dropped during migration)
- Remove production .expect() in get_strict(), replace with .ok_or_else()
- Clean up unwrap_or_default() in key_for() to use .next() directly
- Log warning for MCP manifests missing url field instead of silent empty
- Run cargo fmt to fix formatting diffs

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* ci: re-trigger CI with correct base branch (staging)

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(ci): improve no-panics check to properly exclude test modules

The grep-based filter only excluded lines literally containing
#[cfg(test)], #[test], or 'mod tests' — not lines *inside* test
modules. Use awk to track hunk context from diff @@ headers and
skip all added lines within test module hunks.

[skip-regression-check]

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* refactor(registry): remove slack-mcp MCP entry (conflicts with WASM slack tool)

Remove slack-mcp.json alongside the already-excluded github MCP
entry — both conflict with existing WASM tools of the same name.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(registry): address re-review — skip invalid MCP entries, fix install order

- to_registry_entry() now returns Option<RegistryEntry>; MCP manifests
  missing a url field are skipped with a warning instead of creating
  broken entries with empty URLs
- Move McpServer early-return before require_source() in install paths
  so the error message is clear ("cannot install MCP servers") rather
  than the misleading "missing source spec"
- Add test for MCP manifest with missing URL returning None

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

.github/workflows/code_style.yml

@@ -89,19 +89,34 @@ jobs:
     - name: Check for .unwrap(), .expect(), assert!() in production code
       run: |
         BASE="${{ github.event.pull_request.base.sha }}"
-        # Get added lines in .rs files (production only, exclude tests/)
+        # Get the full diff for .rs files (production only, exclude tests/ directory)
-        ADDED=$(git diff "$BASE"...HEAD -- 'src/**/*.rs' 'crates/**/*.rs' \
+        DIFF=$(git diff "$BASE"...HEAD -- 'src/**/*.rs' 'crates/**/*.rs' || true)
-          | grep -E '^\+[^+]' || true)
 
-        if [ -z "$ADDED" ]; then
+        if [ -z "$DIFF" ]; then
           echo "No production Rust changes detected."
           exit 0
         fi
 
-        # Match panic-inducing patterns, excluding test code and safety suppressions
+        # Extract added lines, skipping those inside test modules.
+        # Track whether we're inside a test module by watching hunk headers
+        # (lines starting with @@) whose context contains "mod tests" or "#[cfg(test)]".
+        ADDED=$(echo "$DIFF" | awk '
+          /^@@/ {
+            # Hunk context (after the second @@) tells us the function/module scope
+            in_test = (tolower($0) ~ /mod tests/ || $0 ~ /#\[cfg\(test\)\]/ || $0 ~ /#\[test\]/)
+          }
+          /^\+[^+]/ && !in_test { print }
+        ' || true)
+
+        if [ -z "$ADDED" ]; then
+          echo "No production Rust changes detected (test-only changes excluded)."
+          exit 0
+        fi
+
+        # Match panic-inducing patterns, excluding safety suppressions
         VIOLATIONS=$(echo "$ADDED" \
           | grep -E '\.(unwrap|expect)\(|[^_]assert(_eq|_ne)?!' \
-          | grep -Ev 'debug_assert|// safety:|#\[cfg\(test\)\]|#\[test\]|mod tests' \
+          | grep -Ev 'debug_assert|// safety:' \
           || true)
 
         if [ -n "$VIOLATIONS" ]; then

build.rs

@@ -132,7 +132,7 @@ fn embed_registry_catalog(root: &Path) {
         // No registry dir: write empty catalog
         fs::write(
             &out_path,
-            r#"{"tools":[],"channels":[],"bundles":{"bundles":{}}}"#,
+            r#"{"tools":[],"channels":[],"mcp_servers":[],"bundles":{"bundles":{}}}"#,
         )
         .unwrap();
         return;
@@ -140,6 +140,7 @@ fn embed_registry_catalog(root: &Path) {
 
     let mut tools = Vec::new();
     let mut channels = Vec::new();
+    let mut mcp_servers = Vec::new();
 
     // Collect tool manifests
     let tools_dir = registry_dir.join("tools");
@@ -153,6 +154,12 @@ fn embed_registry_catalog(root: &Path) {
         collect_json_files(&channels_dir, &mut channels);
     }
 
+    // Collect MCP server manifests
+    let mcp_servers_dir = registry_dir.join("mcp-servers");
+    if mcp_servers_dir.is_dir() {
+        collect_json_files(&mcp_servers_dir, &mut mcp_servers);
+    }
+
     // Read bundles
     let bundles_path = registry_dir.join("_bundles.json");
     let bundles_raw = if bundles_path.is_file() {
@@ -163,9 +170,10 @@ fn embed_registry_catalog(root: &Path) {
 
     // Build the combined JSON
     let catalog = format!(
-        r#"{{"tools":[{}],"channels":[{}],"bundles":{}}}"#,
+        r#"{{"tools":[{}],"channels":[{}],"mcp_servers":[{}],"bundles":{}}}"#,
         tools.join(","),
         channels.join(","),
+        mcp_servers.join(","),
         bundles_raw,
     );
 

registry/mcp-servers/asana.json

@@ -0,0 +1,9 @@
+{
+  "name": "asana",
+  "display_name": "Asana",
+  "kind": "mcp_server",
+  "description": "Connect to Asana for task management, projects, and team coordination",
+  "keywords": ["tasks", "projects", "management", "team"],
+  "url": "https://mcp.asana.com/v2/mcp",
+  "auth": "dcr"
+}

registry/mcp-servers/cloudflare.json

@@ -0,0 +1,9 @@
+{
+  "name": "cloudflare",
+  "display_name": "Cloudflare",
+  "kind": "mcp_server",
+  "description": "Connect to Cloudflare for DNS, Workers, KV, and infrastructure management",
+  "keywords": ["cdn", "dns", "workers", "hosting", "infrastructure"],
+  "url": "https://mcp.cloudflare.com/mcp",
+  "auth": "dcr"
+}

registry/mcp-servers/intercom.json

@@ -0,0 +1,9 @@
+{
+  "name": "intercom",
+  "display_name": "Intercom",
+  "kind": "mcp_server",
+  "description": "Connect to Intercom for customer messaging, support, and engagement",
+  "keywords": ["support", "customers", "messaging", "chat", "helpdesk"],
+  "url": "https://mcp.intercom.com/mcp",
+  "auth": "dcr"
+}

registry/mcp-servers/linear.json

@@ -0,0 +1,9 @@
+{
+  "name": "linear",
+  "display_name": "Linear",
+  "kind": "mcp_server",
+  "description": "Connect to Linear for issue tracking, project management, and team workflows",
+  "keywords": ["issues", "tickets", "project", "tracking", "bugs"],
+  "url": "https://mcp.linear.app/sse",
+  "auth": "dcr"
+}

registry/mcp-servers/notion.json

@@ -0,0 +1,9 @@
+{
+  "name": "notion",
+  "display_name": "Notion",
+  "kind": "mcp_server",
+  "description": "Connect to Notion for reading and writing pages, databases, and comments",
+  "keywords": ["notes", "wiki", "docs", "pages", "database"],
+  "url": "https://mcp.notion.com/mcp",
+  "auth": "dcr"
+}

registry/mcp-servers/sentry.json

@@ -0,0 +1,9 @@
+{
+  "name": "sentry",
+  "display_name": "Sentry",
+  "kind": "mcp_server",
+  "description": "Connect to Sentry for error tracking, performance monitoring, and debugging",
+  "keywords": ["errors", "monitoring", "debugging", "crashes", "performance"],
+  "url": "https://mcp.sentry.dev/mcp",
+  "auth": "dcr"
+}

registry/mcp-servers/stripe.json

@@ -0,0 +1,9 @@
+{
+  "name": "stripe",
+  "display_name": "Stripe",
+  "kind": "mcp_server",
+  "description": "Connect to Stripe for payment processing, subscriptions, and financial data",
+  "keywords": ["payments", "billing", "subscriptions", "invoices", "finance"],
+  "url": "https://mcp.stripe.com",
+  "auth": "dcr"
+}

src/app.rs

@@ -594,7 +594,7 @@ impl AppBuilder {
                 let entries: Vec<_> = catalog
                     .all()
                     .iter()
-                    .map(|m| m.to_registry_entry())
+                    .filter_map(|m| m.to_registry_entry())
                     .collect();
                 tracing::debug!(
                     count = entries.len(),

src/cli/registry.rs

@@ -127,7 +127,11 @@ fn cmd_list(
                 .unwrap_or("none");
             println!(
                 "{:<20} {:<8} {:<8} {:<10} {}",
-                m.name, m.kind, m.version, auth, m.description
+                m.name,
+                m.kind,
+                m.version.as_deref().unwrap_or("-"),
+                auth,
+                m.description
             );
         } else {
             println!("{:<20} {:<8} {}", m.name, m.kind, m.description);
@@ -173,17 +177,25 @@ fn cmd_info(catalog: &RegistryCatalog, name: &str) -> anyhow::Result<()> {
         .map_err(|e| anyhow::anyhow!("{}", e))?;
 
     println!("{} ({})", manifest.display_name, manifest.kind);
-    println!("  Version: {}", manifest.version);
+    if let Some(ref version) = manifest.version {
+        println!("  Version: {}", version);
+    }
     println!("  {}", manifest.description);
 
     if !manifest.keywords.is_empty() {
         println!("  Keywords: {}", manifest.keywords.join(", "));
     }
 
-    println!("\nSource:");
+    if let Some(ref source) = manifest.source {
-    println!("  Directory: {}", manifest.source.dir);
+        println!("\nSource:");
-    println!("  Crate: {}", manifest.source.crate_name);
+        println!("  Directory: {}", source.dir);
-    println!("  Capabilities: {}", manifest.source.capabilities);
+        println!("  Crate: {}", source.crate_name);
+        println!("  Capabilities: {}", source.capabilities);
+    }
+
+    if let Some(ref url) = manifest.url {
+        println!("\nMCP Server URL: {}", url);
+    }
 
     if let Some(artifact) = manifest.artifacts.get("wasm32-wasip2") {
         println!("\nArtifact (wasm32-wasip2):");

src/extensions/registry.rs

@@ -232,198 +232,11 @@ pub fn builtin_entries() -> Vec<RegistryEntry> {
 }
 
 /// Well-known extensions, with an optional relay URL for the channel-relay entry.
+///
+/// MCP server entries are loaded from `registry/mcp-servers/*.json` via the catalog
+/// system. Only runtime-dependent entries (like channel-relay) remain here.
 pub fn builtin_entries_with_relay(relay_url: Option<String>) -> Vec<RegistryEntry> {
-    let mut entries = vec![
+    let mut entries = vec![];
-        // -- MCP Servers --
-        RegistryEntry {
-            name: "notion".to_string(),
-            display_name: "Notion".to_string(),
-            kind: ExtensionKind::McpServer,
-            description: "Connect to Notion for reading and writing pages, databases, and comments"
-                .to_string(),
-            keywords: vec![
-                "notes".into(),
-                "wiki".into(),
-                "docs".into(),
-                "pages".into(),
-                "database".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.notion.com/mcp".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "linear".to_string(),
-            display_name: "Linear".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to Linear for issue tracking, project management, and team workflows"
-                    .to_string(),
-            keywords: vec![
-                "issues".into(),
-                "tickets".into(),
-                "project".into(),
-                "tracking".into(),
-                "bugs".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.linear.app/sse".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "github".to_string(),
-            display_name: "GitHub".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to GitHub for repository management, issues, PRs, and code search"
-                    .to_string(),
-            keywords: vec![
-                "git".into(),
-                "repos".into(),
-                "code".into(),
-                "pull-request".into(),
-                "issues".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://api.githubcopilot.com/mcp/".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "slack-mcp".to_string(),
-            display_name: "Slack MCP".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to Slack via MCP for messaging, channel management, and team communication"
-                    .to_string(),
-            keywords: vec![
-                "messaging".into(),
-                "chat".into(),
-                "channels".into(),
-                "team".into(),
-                "communication".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.slack.com".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "sentry".to_string(),
-            display_name: "Sentry".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to Sentry for error tracking, performance monitoring, and debugging"
-                    .to_string(),
-            keywords: vec![
-                "errors".into(),
-                "monitoring".into(),
-                "debugging".into(),
-                "crashes".into(),
-                "performance".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.sentry.dev/mcp".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "stripe".to_string(),
-            display_name: "Stripe".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to Stripe for payment processing, subscriptions, and financial data"
-                    .to_string(),
-            keywords: vec![
-                "payments".into(),
-                "billing".into(),
-                "subscriptions".into(),
-                "invoices".into(),
-                "finance".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.stripe.com".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "cloudflare".to_string(),
-            display_name: "Cloudflare".to_string(),
-            kind: ExtensionKind::McpServer,
-            description:
-                "Connect to Cloudflare for DNS, Workers, KV, and infrastructure management"
-                    .to_string(),
-            keywords: vec![
-                "cdn".into(),
-                "dns".into(),
-                "workers".into(),
-                "hosting".into(),
-                "infrastructure".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.cloudflare.com/mcp".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "asana".to_string(),
-            display_name: "Asana".to_string(),
-            kind: ExtensionKind::McpServer,
-            description: "Connect to Asana for task management, projects, and team coordination"
-                .to_string(),
-            keywords: vec![
-                "tasks".into(),
-                "projects".into(),
-                "management".into(),
-                "team".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.asana.com/v2/mcp".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        RegistryEntry {
-            name: "intercom".to_string(),
-            display_name: "Intercom".to_string(),
-            kind: ExtensionKind::McpServer,
-            description: "Connect to Intercom for customer messaging, support, and engagement"
-                .to_string(),
-            keywords: vec![
-                "support".into(),
-                "customers".into(),
-                "messaging".into(),
-                "chat".into(),
-                "helpdesk".into(),
-            ],
-            source: ExtensionSource::McpUrl {
-                url: "https://mcp.intercom.com/mcp".to_string(),
-            },
-            fallback_source: None,
-            auth_hint: AuthHint::Dcr,
-            version: None,
-        },
-        // WASM channels (telegram, slack, discord, whatsapp) come from the embedded
-        // registry catalog (registry/channels/*.json) with WasmDownload URLs pointing
-        // to GitHub release artifacts. See new_with_catalog() for merging.
-    ];
 
     // Conditionally add channel-relay entries when relay URL is configured
     if let Some(relay_url) = relay_url {
@@ -545,9 +358,21 @@ mod tests {
         assert_eq!(score, 0, "No match should score 0");
     }
 
+    /// Helper to create a registry with catalog entries (MCP servers come from catalog now).
+    fn registry_with_catalog() -> ExtensionRegistry {
+        let catalog = crate::registry::catalog::RegistryCatalog::load_or_embedded()
+            .expect("catalog should load");
+        let catalog_entries: Vec<RegistryEntry> = catalog
+            .all()
+            .iter()
+            .filter_map(|m| m.to_registry_entry())
+            .collect();
+        ExtensionRegistry::new_with_catalog(catalog_entries)
+    }
+
     #[tokio::test]
     async fn test_search_returns_sorted() {
-        let registry = ExtensionRegistry::new();
+        let registry = registry_with_catalog();
         let results = registry.search("notion").await;
 
         assert!(!results.is_empty(), "Should find notion in registry");
@@ -556,7 +381,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_search_empty_query_returns_all() {
-        let registry = ExtensionRegistry::new();
+        let registry = registry_with_catalog();
         let results = registry.search("").await;
 
         assert!(results.len() > 5, "Empty query should return all entries");
@@ -564,7 +389,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_search_by_keyword() {
-        let registry = ExtensionRegistry::new();
+        let registry = registry_with_catalog();
         let results = registry.search("issues tickets").await;
 
         assert!(
@@ -578,7 +403,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_get_exact_name() {
-        let registry = ExtensionRegistry::new();
+        let registry = registry_with_catalog();
 
         let entry = registry.get("notion").await;
         assert!(entry.is_some());
@@ -658,17 +483,30 @@ mod tests {
                 auth_hint: AuthHint::CapabilitiesAuth,
                 version: None,
             },
-            // This shares a name with the builtin slack-mcp but has a different kind, so both should appear
+            // Two entries with same name but different kinds should coexist
             RegistryEntry {
-                name: "slack-mcp".to_string(),
+                name: "dual-ext".to_string(),
-                display_name: "Slack MCP WASM".to_string(),
+                display_name: "Dual MCP".to_string(),
+                kind: ExtensionKind::McpServer,
+                description: "Dual extension MCP server".to_string(),
+                keywords: vec!["messaging".into()],
+                source: ExtensionSource::McpUrl {
+                    url: "https://mcp.example.com".to_string(),
+                },
+                fallback_source: None,
+                auth_hint: AuthHint::Dcr,
+                version: None,
+            },
+            RegistryEntry {
+                name: "dual-ext".to_string(),
+                display_name: "Dual WASM".to_string(),
                 kind: ExtensionKind::WasmTool,
-                description: "Slack WASM tool".to_string(),
+                description: "Dual extension WASM tool".to_string(),
                 keywords: vec!["messaging".into()],
                 source: ExtensionSource::WasmBuildable {
-                    source_dir: "tools-src/slack".to_string(),
+                    source_dir: "tools-src/dual".to_string(),
-                    build_dir: Some("tools-src/slack".to_string()),
+                    build_dir: Some("tools-src/dual".to_string()),
-                    crate_name: Some("slack-tool".to_string()),
+                    crate_name: Some("dual-tool".to_string()),
                 },
                 fallback_source: None,
                 auth_hint: AuthHint::CapabilitiesAuth,
@@ -683,41 +521,56 @@ mod tests {
         assert!(!results.is_empty(), "Should find telegram from catalog");
         assert_eq!(results[0].entry.name, "telegram");
 
-        // Should have both builtin MCP slack-mcp and catalog WASM slack-mcp
+        // Should have both MCP and WASM entries with the same name
-        let results = registry.search("slack").await;
+        let results = registry.search("dual-ext").await;
-        let slack_mcp = results
+        let has_mcp = results
             .iter()
-            .any(|r| r.entry.name == "slack-mcp" && r.entry.kind == ExtensionKind::McpServer);
+            .any(|r| r.entry.name == "dual-ext" && r.entry.kind == ExtensionKind::McpServer);
-        let slack_wasm = results
+        let has_wasm = results
             .iter()
-            .any(|r| r.entry.name == "slack-mcp" && r.entry.kind == ExtensionKind::WasmTool);
+            .any(|r| r.entry.name == "dual-ext" && r.entry.kind == ExtensionKind::WasmTool);
-        assert!(slack_mcp, "Should have builtin MCP slack-mcp");
+        assert!(has_mcp, "Should have MCP dual-ext");
-        assert!(slack_wasm, "Should have catalog WASM slack-mcp");
+        assert!(has_wasm, "Should have WASM dual-ext");
     }
 
     #[tokio::test]
     async fn test_new_with_catalog_dedup_same_kind() {
-        // A catalog entry with same name AND kind as a builtin should be skipped
+        // When two catalog entries share name AND kind, only the first should be kept
-        let catalog_entries = vec![RegistryEntry {
+        let catalog_entries = vec![
-            name: "slack-mcp".to_string(),
+            RegistryEntry {
-            display_name: "Slack MCP Override".to_string(),
+                name: "test-ext".to_string(),
-            kind: ExtensionKind::McpServer, // same kind as builtin slack-mcp
+                display_name: "Test First".to_string(),
-            description: "Should be skipped".to_string(),
+                kind: ExtensionKind::McpServer,
-            keywords: vec![],
+                description: "First entry".to_string(),
-            source: ExtensionSource::McpUrl {
+                keywords: vec![],
-                url: "https://other.slack.com".to_string(),
+                source: ExtensionSource::McpUrl {
+                    url: "https://first.example.com".to_string(),
+                },
+                fallback_source: None,
+                auth_hint: AuthHint::Dcr,
+                version: None,
             },
-            fallback_source: None,
+            RegistryEntry {
-            auth_hint: AuthHint::Dcr,
+                name: "test-ext".to_string(),
-            version: None,
+                display_name: "Test Duplicate".to_string(),
-        }];
+                kind: ExtensionKind::McpServer, // same kind
+                description: "Should be skipped".to_string(),
+                keywords: vec![],
+                source: ExtensionSource::McpUrl {
+                    url: "https://second.example.com".to_string(),
+                },
+                fallback_source: None,
+                auth_hint: AuthHint::Dcr,
+                version: None,
+            },
+        ];
 
         let registry = ExtensionRegistry::new_with_catalog(catalog_entries);
 
-        let entry = registry.get("slack-mcp").await;
+        let entry = registry.get("test-ext").await;
         assert!(entry.is_some());
-        // Should still be the builtin, not the override
+        // Should be the first entry, not the duplicate
-        assert_eq!(entry.unwrap().display_name, "Slack MCP");
+        assert_eq!(entry.unwrap().display_name, "Test First");
     }
 
     #[tokio::test]

src/registry/catalog.rs

@@ -192,6 +192,12 @@ impl RegistryCatalog {
             Self::load_manifests_from_dir(&channels_dir, "channels", &mut manifests)?;
         }
 
+        // Load MCP servers
+        let mcp_servers_dir = registry_dir.join("mcp-servers");
+        if mcp_servers_dir.is_dir() {
+            Self::load_manifests_from_dir(&mcp_servers_dir, "mcp-servers", &mut manifests)?;
+        }
+
         // Load bundles
         let bundles_path = registry_dir.join("_bundles.json");
         let bundles = if bundles_path.is_file() {
@@ -280,8 +286,9 @@ impl RegistryCatalog {
     /// Get a manifest by name. Tries exact key match first ("tools/github"),
     /// then searches by bare name ("github").
     ///
-    /// If a bare name matches both a tool and a channel, returns `None`.
+    /// If a bare name matches more than one prefix, returns `None`.
-    /// Use a qualified key ("tools/github" or "channels/telegram") to disambiguate.
+    /// Use a qualified key ("tools/github", "channels/telegram", or
+    /// "mcp-servers/notion") to disambiguate.
     pub fn get(&self, name: &str) -> Option<&ExtensionManifest> {
         // Try exact key first
         if let Some(m) = self.manifests.get(name) {
@@ -289,14 +296,15 @@ impl RegistryCatalog {
         }
 
         // Try with kind prefix, detecting collisions
-        let tool = self.manifests.get(&format!("tools/{}", name));
+        let candidates: Vec<_> = ["tools", "channels", "mcp-servers"]
-        let channel = self.manifests.get(&format!("channels/{}", name));
+            .iter()
+            .filter_map(|prefix| self.manifests.get(&format!("{}/{}", prefix, name)))
+            .collect();
 
-        match (tool, channel) {
+        if candidates.len() == 1 {
-            (Some(_), Some(_)) => None, // ambiguous
+            Some(candidates[0])
-            (Some(m), None) => Some(m),
+        } else {
-            (None, Some(m)) => Some(m),
+            None // ambiguous or not found
-            (None, None) => None,
         }
     }
 
@@ -308,37 +316,63 @@ impl RegistryCatalog {
             return Ok(m);
         }
 
-        let has_tool = self.manifests.contains_key(&format!("tools/{}", name));
+        let prefixes: &[(&str, &str)] = &[
-        let has_channel = self.manifests.contains_key(&format!("channels/{}", name));
+            ("tools", "tool"),
+            ("channels", "channel"),
+            ("mcp-servers", "mcp_server"),
+        ];
 
-        match (has_tool, has_channel) {
+        let matches: Vec<_> = prefixes
-            (true, true) => Err(RegistryError::AmbiguousName {
+            .iter()
-                name: name.to_string(),
+            .filter(|(prefix, _)| self.manifests.contains_key(&format!("{}/{}", prefix, name)))
-                kind_a: "tool",
+            .collect();
-                prefix_a: "tools",
+
-                kind_b: "channel",
+        match matches.len() {
-                prefix_b: "channels",
+            0 => Err(RegistryError::ExtensionNotFound(name.to_string())),
-            }),
+            1 => {
-            (true, false) => Ok(self.manifests.get(&format!("tools/{}", name)).unwrap()),
+                let (prefix, _) = matches[0];
-            (false, true) => Ok(self.manifests.get(&format!("channels/{}", name)).unwrap()),
+                let key = format!("{}/{}", prefix, name);
-            (false, false) => Err(RegistryError::ExtensionNotFound(name.to_string())),
+                self.manifests
+                    .get(&key)
+                    .ok_or_else(|| RegistryError::ExtensionNotFound(name.to_string()))
+            }
+            _ => {
+                let (prefix_a, kind_a) = matches[0];
+                let (prefix_b, kind_b) = matches[1];
+                Err(RegistryError::AmbiguousName {
+                    name: name.to_string(),
+                    kind_a,
+                    prefix_a,
+                    kind_b,
+                    prefix_b,
+                })
+            }
         }
     }
 
-    /// Get the full key ("tools/github" or "channels/telegram") for a manifest.
+    /// Get the full key ("tools/github", "channels/telegram", or
+    /// "mcp-servers/notion") for a manifest.
     pub fn key_for(&self, name: &str) -> Option<String> {
         if self.manifests.contains_key(name) {
             return Some(name.to_string());
         }
 
-        let has_tool = self.manifests.contains_key(&format!("tools/{}", name));
+        let matches: Vec<String> = ["tools", "channels", "mcp-servers"]
-        let has_channel = self.manifests.contains_key(&format!("channels/{}", name));
+            .iter()
+            .filter_map(|prefix| {
+                let key = format!("{}/{}", prefix, name);
+                if self.manifests.contains_key(&key) {
+                    Some(key)
+                } else {
+                    None
+                }
+            })
+            .collect();
 
-        match (has_tool, has_channel) {
+        if matches.len() == 1 {
-            (true, true) => None, // ambiguous
+            matches.into_iter().next()
-            (true, false) => Some(format!("tools/{}", name)),
+        } else {
-            (false, true) => Some(format!("channels/{}", name)),
+            None // ambiguous or not found
-            (false, false) => None,
         }
     }
 
@@ -476,8 +510,10 @@ mod tests {
     fn create_test_registry(dir: &Path) {
         let tools_dir = dir.join("tools");
         let channels_dir = dir.join("channels");
+        let mcp_dir = dir.join("mcp-servers");
         fs::create_dir_all(&tools_dir).unwrap();
         fs::create_dir_all(&channels_dir).unwrap();
+        fs::create_dir_all(&mcp_dir).unwrap();
 
         fs::write(
             tools_dir.join("slack.json"),
@@ -540,6 +576,20 @@ mod tests {
         )
         .unwrap();
 
+        fs::write(
+            mcp_dir.join("notion.json"),
+            r#"{
+                "name": "notion",
+                "display_name": "Notion",
+                "kind": "mcp_server",
+                "description": "Connect to Notion for pages and databases",
+                "keywords": ["notes", "wiki"],
+                "url": "https://mcp.notion.com/mcp",
+                "auth": "dcr"
+            }"#,
+        )
+        .unwrap();
+
         fs::write(
             dir.join("_bundles.json"),
             r#"{
@@ -565,7 +615,7 @@ mod tests {
         create_test_registry(tmp.path());
 
         let catalog = RegistryCatalog::load(tmp.path()).unwrap();
-        assert_eq!(catalog.all().len(), 3);
+        assert_eq!(catalog.all().len(), 4);
     }
 
     #[test]
@@ -579,6 +629,9 @@ mod tests {
 
         let channels = catalog.list(Some(ManifestKind::Channel), None);
         assert_eq!(channels.len(), 1);
+
+        let mcp_servers = catalog.list(Some(ManifestKind::McpServer), None);
+        assert_eq!(mcp_servers.len(), 1);
     }
 
     #[test]
@@ -603,10 +656,12 @@ mod tests {
 
         // Full key
         assert!(catalog.get("tools/slack").is_some());
+        assert!(catalog.get("mcp-servers/notion").is_some());
 
         // Bare name
         assert!(catalog.get("slack").is_some());
         assert!(catalog.get("telegram").is_some());
+        assert!(catalog.get("notion").is_some());
 
         // Missing
         assert!(catalog.get("nonexistent").is_none());

src/registry/embedded.rs

@@ -20,6 +20,8 @@ struct EmbeddedCatalogRaw {
     #[serde(default)]
     channels: Vec<ExtensionManifest>,
     #[serde(default)]
+    mcp_servers: Vec<ExtensionManifest>,
+    #[serde(default)]
     bundles: BundlesFile,
 }
 
@@ -52,6 +54,10 @@ fn parsed_catalog() -> &'static ParsedCatalog {
             let key = format!("channels/{}", m.name);
             manifests.insert(key, m);
         }
+        for m in raw.mcp_servers {
+            let key = format!("mcp-servers/{}", m.name);
+            manifests.insert(key, m);
+        }
 
         ParsedCatalog {
             manifests,

src/registry/installer.rs

@@ -7,7 +7,7 @@ use tokio::fs;
 
 use crate::bootstrap::ironclaw_base_dir;
 use crate::registry::catalog::RegistryError;
-use crate::registry::manifest::{BundleDefinition, ExtensionManifest, ManifestKind};
+use crate::registry::manifest::{BundleDefinition, ExtensionManifest, ManifestKind, SourceSpec};
 
 // GitHub-only by design. New trusted hosts (e.g. a NEAR AI CDN) must be
 // explicitly added here; unknown hosts fall back to source build with a
@@ -98,12 +98,29 @@ fn validate_manifest_install_inputs(manifest: &ExtensionManifest) -> Result<(),
         });
     }
 
+    // MCP servers are not installed via this path
+    if manifest.kind == ManifestKind::McpServer {
+        return Ok(());
+    }
+
+    let source = match &manifest.source {
+        Some(s) => s,
+        None => {
+            return Err(RegistryError::InvalidManifest {
+                name: manifest.name.clone(),
+                field: "source",
+                reason: "WASM extensions must have a source spec".to_string(),
+            });
+        }
+    };
+
     let expected_prefix = match manifest.kind {
         ManifestKind::Tool => "tools-src/",
         ManifestKind::Channel => "channels-src/",
+        ManifestKind::McpServer => unreachable!(),
     };
 
-    if !manifest.source.dir.starts_with(expected_prefix) {
+    if !source.dir.starts_with(expected_prefix) {
         return Err(RegistryError::InvalidManifest {
             name: manifest.name.clone(),
             field: "source.dir",
@@ -111,7 +128,7 @@ fn validate_manifest_install_inputs(manifest: &ExtensionManifest) -> Result<(),
         });
     }
 
-    let source_path = Path::new(&manifest.source.dir);
+    let source_path = Path::new(&source.dir);
     let has_unsafe_component = source_path.components().any(|component| {
         matches!(
             component,
@@ -127,9 +144,9 @@ fn validate_manifest_install_inputs(manifest: &ExtensionManifest) -> Result<(),
         });
     }
 
-    let has_path_separator = manifest.source.capabilities.contains('/')
+    let has_path_separator = source.capabilities.contains('/')
-        || manifest.source.capabilities.contains('\\')
+        || source.capabilities.contains('\\')
-        || manifest.source.capabilities.contains("..");
+        || source.capabilities.contains("..");
 
     if has_path_separator {
         return Err(RegistryError::InvalidManifest {
@@ -142,6 +159,18 @@ fn validate_manifest_install_inputs(manifest: &ExtensionManifest) -> Result<(),
     Ok(())
 }
 
+/// Extract the source spec from a manifest, returning an error if absent.
+fn require_source(manifest: &ExtensionManifest) -> Result<&SourceSpec, RegistryError> {
+    manifest
+        .source
+        .as_ref()
+        .ok_or_else(|| RegistryError::InvalidManifest {
+            name: manifest.name.clone(),
+            field: "source",
+            reason: "WASM extensions must have a source spec".to_string(),
+        })
+}
+
 fn download_failure_reason(error: &reqwest::Error) -> String {
     if error.is_timeout() {
         "request timed out".to_string()
@@ -206,7 +235,17 @@ impl RegistryInstaller {
     ) -> Result<InstallOutcome, RegistryError> {
         validate_manifest_install_inputs(manifest)?;
 
-        let source_dir = self.repo_root.join(&manifest.source.dir);
+        if manifest.kind == ManifestKind::McpServer {
+            return Err(RegistryError::InvalidManifest {
+                name: manifest.name.clone(),
+                field: "kind",
+                reason: "MCP servers cannot be installed from source".to_string(),
+            });
+        }
+
+        let source = require_source(manifest)?;
+
+        let source_dir = self.repo_root.join(&source.dir);
         if !source_dir.exists() {
             return Err(RegistryError::ManifestRead {
                 path: source_dir.clone(),
@@ -217,6 +256,7 @@ impl RegistryInstaller {
         let target_dir = match manifest.kind {
             ManifestKind::Tool => &self.tools_dir,
             ManifestKind::Channel => &self.channels_dir,
+            ManifestKind::McpServer => unreachable!(),
         };
 
         fs::create_dir_all(target_dir)
@@ -242,7 +282,7 @@ impl RegistryInstaller {
             manifest.display_name,
             source_dir.display()
         );
-        let crate_name = &manifest.source.crate_name;
+        let crate_name = &source.crate_name;
         let wasm_path =
             crate::registry::artifacts::build_wasm_component(&source_dir, crate_name, true)
                 .await
@@ -258,7 +298,7 @@ impl RegistryInstaller {
             .map_err(RegistryError::Io)?;
 
         // Copy capabilities file
-        let caps_source = source_dir.join(&manifest.source.capabilities);
+        let caps_source = source_dir.join(&source.capabilities);
         let target_caps = target_dir.join(format!("{}.capabilities.json", manifest.name));
         let has_capabilities = if caps_source.exists() {
             fs::copy(&caps_source, &target_caps)
@@ -296,6 +336,16 @@ impl RegistryInstaller {
         // catch it first.
         validate_manifest_install_inputs(manifest)?;
 
+        if manifest.kind == ManifestKind::McpServer {
+            return Err(RegistryError::InvalidManifest {
+                name: manifest.name.clone(),
+                field: "kind",
+                reason: "MCP servers cannot be installed via the WASM installer".to_string(),
+            });
+        }
+
+        let source = require_source(manifest)?;
+
         let has_artifact = manifest
             .artifacts
             .get("wasm32-wasip2")
@@ -306,7 +356,7 @@ impl RegistryInstaller {
             return self.install_from_source(manifest, force).await;
         }
 
-        let source_dir = self.repo_root.join(&manifest.source.dir);
+        let source_dir = self.repo_root.join(&source.dir);
 
         match self.install_from_artifact(manifest, force).await {
             Ok(outcome) => Ok(outcome),
@@ -391,6 +441,13 @@ impl RegistryInstaller {
         let target_dir = match manifest.kind {
             ManifestKind::Tool => &self.tools_dir,
             ManifestKind::Channel => &self.channels_dir,
+            ManifestKind::McpServer => {
+                return Err(RegistryError::InvalidManifest {
+                    name: manifest.name.clone(),
+                    field: "kind",
+                    reason: "MCP servers cannot be installed as artifacts".to_string(),
+                });
+            }
         };
 
         fs::create_dir_all(target_dir)
@@ -458,12 +515,9 @@ impl RegistryInstaller {
                         false
                     }
                 }
-            } else {
+            } else if let Some(ref source) = manifest.source {
                 // Legacy fallback: try source tree
-                let caps_source = self
+                let caps_source = self.repo_root.join(&source.dir).join(&source.capabilities);
-                    .repo_root
-                    .join(&manifest.source.dir)
-                    .join(&manifest.source.capabilities);
                 if caps_source.exists() {
                     fs::copy(&caps_source, &target_caps)
                         .await
@@ -472,6 +526,8 @@ impl RegistryInstaller {
                 } else {
                     false
                 }
+            } else {
+                false
             }
         };
 
@@ -775,17 +831,19 @@ mod tests {
             name: name.to_string(),
             display_name: name.to_string(),
             kind,
-            version: "0.1.0".to_string(),
+            version: Some("0.1.0".to_string()),
             description: "test manifest".to_string(),
             keywords: Vec::new(),
-            source: SourceSpec {
+            source: Some(SourceSpec {
                 dir: source_dir.to_string(),
                 capabilities: format!("{}.capabilities.json", name),
                 crate_name: name.to_string(),
-            },
+            }),
             artifacts,
             auth_summary: None,
             tags: Vec::new(),
+            url: None,
+            auth: None,
         }
     }
 

src/registry/manifest.rs

@@ -7,7 +7,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::extensions::{AuthHint, ExtensionKind, ExtensionSource, RegistryEntry};
 
-/// A single extension manifest loaded from `registry/{tools,channels}/<name>.json`.
+/// A single extension manifest loaded from `registry/{tools,channels,mcp-servers}/<name>.json`.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ExtensionManifest {
     /// Unique identifier (matches crate name stem, e.g. "slack").
@@ -16,11 +16,12 @@ pub struct ExtensionManifest {
     /// Human-readable name (e.g. "Slack").
     pub display_name: String,
 
-    /// Whether this is a tool or channel.
+    /// Whether this is a tool, channel, or MCP server.
     pub kind: ManifestKind,
 
-    /// Semver version from Cargo.toml.
+    /// Semver version from Cargo.toml. Optional for MCP server manifests.
-    pub version: String,
+    #[serde(default)]
+    pub version: Option<String>,
 
     /// One-line description.
     pub description: String,
@@ -29,8 +30,9 @@ pub struct ExtensionManifest {
     #[serde(default)]
     pub keywords: Vec<String>,
 
-    /// Source code location and build info.
+    /// Source code location and build info. Absent for MCP server manifests.
-    pub source: SourceSpec,
+    #[serde(default)]
+    pub source: Option<SourceSpec>,
 
     /// Pre-built binary artifacts keyed by target triple.
     #[serde(default)]
@@ -43,6 +45,15 @@ pub struct ExtensionManifest {
     /// Tags for filtering (e.g. "default", "messaging", "google").
     #[serde(default)]
     pub tags: Vec<String>,
+
+    /// MCP server URL. Only present for `McpServer` manifests.
+    #[serde(default)]
+    pub url: Option<String>,
+
+    /// MCP auth method: "dcr", "oauth_pre_configured:<setup_url>", or "none".
+    /// Only present for `McpServer` manifests.
+    #[serde(default)]
+    pub auth: Option<String>,
 }
 
 /// Extension kind as declared in manifests.
@@ -51,6 +62,7 @@ pub struct ExtensionManifest {
 pub enum ManifestKind {
     Tool,
     Channel,
+    McpServer,
 }
 
 impl From<ManifestKind> for ExtensionKind {
@@ -58,6 +70,7 @@ impl From<ManifestKind> for ExtensionKind {
         match kind {
             ManifestKind::Tool => ExtensionKind::WasmTool,
             ManifestKind::Channel => ExtensionKind::WasmChannel,
+            ManifestKind::McpServer => ExtensionKind::McpServer,
         }
     }
 }
@@ -67,6 +80,7 @@ impl std::fmt::Display for ManifestKind {
         match self {
             ManifestKind::Tool => write!(f, "tool"),
             ManifestKind::Channel => write!(f, "channel"),
+            ManifestKind::McpServer => write!(f, "mcp_server"),
         }
     }
 }
@@ -153,12 +167,64 @@ pub struct BundlesFile {
 impl ExtensionManifest {
     /// Convert this manifest into a [`RegistryEntry`] for use with the in-chat
     /// extension discovery system.
-    pub fn to_registry_entry(&self) -> RegistryEntry {
+    ///
-        let buildable = ExtensionSource::WasmBuildable {
+    /// Returns `None` for MCP server manifests missing a `url` field.
-            source_dir: self.source.dir.clone(),
+    pub fn to_registry_entry(&self) -> Option<RegistryEntry> {
-            build_dir: Some(self.source.dir.clone()),
+        if self.kind == ManifestKind::McpServer {
-            crate_name: Some(self.source.crate_name.clone()),
+            return self.to_mcp_registry_entry();
+        }
+
+        Some(self.to_wasm_registry_entry())
+    }
+
+    /// Build a [`RegistryEntry`] for an MCP server manifest.
+    fn to_mcp_registry_entry(&self) -> Option<RegistryEntry> {
+        let url = match &self.url {
+            Some(u) => u.clone(),
+            None => {
+                tracing::warn!(
+                    "MCP server manifest '{}' is missing 'url' field, skipping",
+                    self.name
+                );
+                return None;
+            }
         };
+        let auth_hint = match self.auth.as_deref() {
+            Some("dcr") | None => AuthHint::Dcr,
+            Some("none") => AuthHint::None,
+            Some(other) if other.starts_with("oauth_pre_configured:") => {
+                AuthHint::OAuthPreConfigured {
+                    setup_url: other
+                        .strip_prefix("oauth_pre_configured:")
+                        .unwrap_or("")
+                        .to_string(),
+                }
+            }
+            _ => AuthHint::Dcr,
+        };
+
+        Some(RegistryEntry {
+            name: self.name.clone(),
+            display_name: self.display_name.clone(),
+            kind: ExtensionKind::McpServer,
+            description: self.description.clone(),
+            keywords: self.keywords.clone(),
+            source: ExtensionSource::McpUrl { url },
+            fallback_source: None,
+            auth_hint,
+            version: self.version.clone(),
+        })
+    }
+
+    /// Build a [`RegistryEntry`] for a WASM tool or channel manifest.
+    fn to_wasm_registry_entry(&self) -> RegistryEntry {
+        let source_spec = self.source.as_ref();
+
+        let buildable = source_spec.map(|s| ExtensionSource::WasmBuildable {
+            source_dir: s.dir.clone(),
+            build_dir: Some(s.dir.clone()),
+            crate_name: Some(s.crate_name.clone()),
+        });
 
         // Prefer pre-built artifact download when a URL is available,
         // with build-from-source as fallback in case the download fails (e.g., 404).
@@ -170,13 +236,32 @@ impl ExtensionManifest {
                         wasm_url: url.clone(),
                         capabilities_url: artifact.capabilities_url.clone(),
                     },
-                    Some(Box::new(buildable)),
+                    buildable.map(Box::new),
                 )
+            } else if let Some(b) = buildable {
+                (b, None)
             } else {
-                (buildable, None)
+                // No source spec and no download URL — use a placeholder
+                (
+                    ExtensionSource::WasmBuildable {
+                        source_dir: String::new(),
+                        build_dir: None,
+                        crate_name: None,
+                    },
+                    None,
+                )
             }
+        } else if let Some(b) = buildable {
+            (b, None)
         } else {
-            (buildable, None)
+            (
+                ExtensionSource::WasmBuildable {
+                    source_dir: String::new(),
+                    build_dir: None,
+                    crate_name: None,
+                },
+                None,
+            )
         };
 
         let auth_hint = match self.auth_summary.as_ref().and_then(|a| a.method.as_deref()) {
@@ -195,7 +280,7 @@ impl ExtensionManifest {
             source,
             fallback_source,
             auth_hint,
-            version: Some(self.version.clone()),
+            version: self.version.clone(),
         }
     }
 }
@@ -234,10 +319,10 @@ mod tests {
         let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
         assert_eq!(manifest.name, "slack");
         assert_eq!(manifest.kind, ManifestKind::Tool);
-        assert_eq!(manifest.version, "0.1.0");
+        assert_eq!(manifest.version.as_deref(), Some("0.1.0"));
         assert!(manifest.tags.contains(&"default".to_string()));
 
-        let entry = manifest.to_registry_entry();
+        let entry = manifest.to_registry_entry().unwrap();
         assert_eq!(entry.kind, ExtensionKind::WasmTool);
     }
 
@@ -262,7 +347,7 @@ mod tests {
         assert!(manifest.auth_summary.is_none());
         assert!(manifest.artifacts.is_empty());
 
-        let entry = manifest.to_registry_entry();
+        let entry = manifest.to_registry_entry().unwrap();
         assert_eq!(entry.kind, ExtensionKind::WasmChannel);
     }
 
@@ -296,6 +381,7 @@ mod tests {
     fn test_manifest_kind_display() {
         assert_eq!(ManifestKind::Tool.to_string(), "tool");
         assert_eq!(ManifestKind::Channel.to_string(), "channel");
+        assert_eq!(ManifestKind::McpServer.to_string(), "mcp_server");
     }
 
     /// When a manifest has a download URL in artifacts, to_registry_entry()
@@ -324,7 +410,7 @@ mod tests {
         }"#;
 
         let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
-        let entry = manifest.to_registry_entry();
+        let entry = manifest.to_registry_entry().unwrap();
 
         // Primary source should be WasmDownload
         assert!(
@@ -374,7 +460,7 @@ mod tests {
         }"#;
 
         let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
-        let entry = manifest.to_registry_entry();
+        let entry = manifest.to_registry_entry().unwrap();
 
         assert!(
             matches!(&entry.source, ExtensionSource::WasmBuildable { .. }),
@@ -405,7 +491,7 @@ mod tests {
         }"#;
 
         let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
-        let entry = manifest.to_registry_entry();
+        let entry = manifest.to_registry_entry().unwrap();
 
         assert!(
             matches!(&entry.source, ExtensionSource::WasmBuildable { .. }),
@@ -416,4 +502,89 @@ mod tests {
             "Should have no fallback when already using WasmBuildable"
         );
     }
+
+    #[test]
+    fn test_parse_mcp_server_manifest() {
+        let json = r#"{
+            "name": "notion",
+            "display_name": "Notion",
+            "kind": "mcp_server",
+            "description": "Connect to Notion for reading and writing pages, databases, and comments",
+            "keywords": ["notes", "wiki", "docs", "pages", "database"],
+            "url": "https://mcp.notion.com/mcp",
+            "auth": "dcr"
+        }"#;
+
+        let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
+        assert_eq!(manifest.name, "notion");
+        assert_eq!(manifest.kind, ManifestKind::McpServer);
+        assert!(manifest.version.is_none());
+        assert!(manifest.source.is_none());
+        assert_eq!(manifest.url.as_deref(), Some("https://mcp.notion.com/mcp"));
+        assert_eq!(manifest.auth.as_deref(), Some("dcr"));
+
+        let entry = manifest.to_registry_entry().unwrap();
+        assert_eq!(entry.kind, ExtensionKind::McpServer);
+        assert!(
+            matches!(&entry.source, ExtensionSource::McpUrl { url } if url == "https://mcp.notion.com/mcp")
+        );
+        assert!(matches!(&entry.auth_hint, AuthHint::Dcr));
+        assert!(entry.fallback_source.is_none());
+    }
+
+    #[test]
+    fn test_mcp_server_oauth_pre_configured() {
+        let json = r#"{
+            "name": "custom-mcp",
+            "display_name": "Custom MCP",
+            "kind": "mcp_server",
+            "description": "Custom MCP server",
+            "keywords": [],
+            "url": "https://mcp.example.com",
+            "auth": "oauth_pre_configured:https://example.com/setup"
+        }"#;
+
+        let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
+        let entry = manifest.to_registry_entry().unwrap();
+
+        assert!(matches!(
+            &entry.auth_hint,
+            AuthHint::OAuthPreConfigured { setup_url } if setup_url == "https://example.com/setup"
+        ));
+    }
+
+    #[test]
+    fn test_mcp_server_auth_none() {
+        let json = r#"{
+            "name": "local-mcp",
+            "display_name": "Local MCP",
+            "kind": "mcp_server",
+            "description": "Local MCP server",
+            "keywords": [],
+            "url": "http://localhost:8080/mcp",
+            "auth": "none"
+        }"#;
+
+        let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
+        let entry = manifest.to_registry_entry().unwrap();
+
+        assert!(matches!(&entry.auth_hint, AuthHint::None));
+    }
+
+    #[test]
+    fn test_mcp_server_missing_url_returns_none() {
+        let json = r#"{
+            "name": "broken-mcp",
+            "display_name": "Broken MCP",
+            "kind": "mcp_server",
+            "description": "MCP server with no URL",
+            "keywords": []
+        }"#;
+
+        let manifest: ExtensionManifest = serde_json::from_str(json).expect("parse manifest");
+        assert!(
+            manifest.to_registry_entry().is_none(),
+            "MCP manifest without url should return None"
+        );
+    }
 }