feat(mcp-oauth): support static clientId for servers without DCR

Add optional oauth.clientId field to MCP server configuration schema.
When provided, the OAuth provider uses this clientId directly instead of
performing Dynamic Client Registration (DCR). This enables connections
to OAuth-protected MCP servers that don't support RFC 7591 DCR.

Changes:
- BaseConfigSchema: add oauth.clientId optional field
- McpOAuthClientProvider: accept clientId in create() options,
  use it in registerClientIfNeeded() to skip DCR
- McpHub: pass oauth.clientId from config to the provider
- Tests: 2 new tests covering static clientId and precedence over cache

Aligned with VS Code 1.122 feature: MCP OAuth with custom clientId.

Author: proyectoauraorg

src/services/mcp/McpHub.ts

@@ -75,6 +75,11 @@ const BaseConfigSchema = z.object({
 	alwaysAllow: z.array(z.string()).default([]),
 	watchPaths: z.array(z.string()).optional(), // paths to watch for changes and restart server
 	disabledTools: z.array(z.string()).default([]),
+	oauth: z
+		.object({
+			clientId: z.string().optional(),
+		})
+		.optional(),
 })
 
 // Custom error messages for better user feedback
@@ -807,6 +812,7 @@ export class McpHub {
 
 				const authProvider = await McpOAuthClientProvider.create(configInjected.url, this.secretStorage, name, {
 					skipDiscovery,
+					clientId: configInjected.oauth?.clientId,
 				})
 
 				// Pre-register the OAuth client so the SDK can skip its own

src/services/mcp/McpOAuthClientProvider.ts

@@ -86,6 +86,7 @@ export class McpOAuthClientProvider implements OAuthClientProvider {
 		private readonly _authServerMeta: Record<string, any> | null,
 		private readonly _resourceIndicator: string | null,
 		private readonly _clientName: string,
+		private readonly _staticClientId?: string,
 	) {}
 
 	/**
@@ -102,7 +103,7 @@ export class McpOAuthClientProvider implements OAuthClientProvider {
 		serverUrl: string,
 		secretStorage: SecretStorageService,
 		serverName?: string,
-		options?: { skipDiscovery?: boolean },
+		options?: { skipDiscovery?: boolean; clientId?: string },
 	): Promise<McpOAuthClientProvider> {
 		let authServerMeta: Record<string, any> | null = null
 		let resourceIndicator: string | null = null
@@ -151,6 +152,7 @@ export class McpOAuthClientProvider implements OAuthClientProvider {
 			authServerMeta,
 			resourceIndicator,
 			serverName || "Roo Code",
+			options?.clientId,
 		)
 	}
 
@@ -228,6 +230,17 @@ export class McpOAuthClientProvider implements OAuthClientProvider {
 	async registerClientIfNeeded(): Promise<void> {
 		if (this._clientInfo) return // already registered
 
+		// If a static clientId was provided (e.g. from mcp.json oauth.clientId),
+		// use it directly instead of performing Dynamic Client Registration.
+		// This enables connections to OAuth servers that don't support DCR.
+		if (this._staticClientId) {
+			this._clientInfo = {
+				client_id: this._staticClientId,
+				redirect_uris: [this.redirectUrl],
+			}
+			return
+		}
+
 		// Check if we have a cached client_id from previous registration
 		const cachedData = await this._secretStorage.getOAuthData(this._serverUrl)
 		if (cachedData?.client_info) {

src/services/mcp/__tests__/McpOAuthClientProvider.spec.ts

@@ -849,4 +849,49 @@ describe("McpOAuthClientProvider", () => {
 			await provider.close()
 		})
 	})
+
+	describe("static clientId support", () => {
+		it("should use static clientId instead of performing DCR", async () => {
+			const secretStorage = createMockSecretStorage()
+			const provider = await McpOAuthClientProvider.create(
+				"https://example.com/mcp",
+				secretStorage,
+				"test-server",
+				{ clientId: "my-static-client-id" },
+			)
+
+			await provider.registerClientIfNeeded()
+
+			const info = await provider.clientInformation()
+			expect(info?.client_id).toBe("my-static-client-id")
+			await provider.close()
+		})
+
+		it("should use static clientId even when cached data exists", async () => {
+			setupCallbackServerMock()
+			const secretStorage = createMockSecretStorage()
+
+			await secretStorage.saveOAuthData("https://example.com/mcp", {
+				tokens: { access_token: "cached-token", token_type: "Bearer" },
+				expires_at: Date.now() + 3600_000,
+				client_info: {
+					client_id: "cached-client-id",
+					redirect_uris: ["http://localhost:0/callback"],
+				},
+			})
+
+			const provider = await McpOAuthClientProvider.create(
+				"https://example.com/mcp",
+				secretStorage,
+				"test-server",
+				{ clientId: "my-static-client-id" },
+			)
+
+			await provider.registerClientIfNeeded()
+
+			const info = await provider.clientInformation()
+			expect(info?.client_id).toBe("my-static-client-id")
+			await provider.close()
+		})
+	})
 })