Method refreshAccessToken

src/main/lib/oauth.ts:623–658

(
    refreshToken: string,
    clientId: string
  )

  // Refresh access token
  async refreshAccessToken(
    refreshToken: string,
    clientId: string
  ): Promise<OAuthTokens> {
    const metadata = await this.getServerMetadata();

    const params = new URLSearchParams({
      grant_type: 'refresh_token',
      refresh_token: refreshToken,
      client_id: clientId,
    });

    const response = await fetch(metadata.token_endpoint, {
      method: 'POST',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
      body: params.toString(),
    });

    if (!response.ok) {
      throw new Error('Failed to refresh token');
    }

    const data = await response.json() as {
      access_token: string;
      refresh_token?: string;
      expires_in?: number;
      token_type?: string;
    };

    return {
      accessToken: data.access_token,
      refreshToken: data.refresh_token || refreshToken,
      expiresAt: data.expires_in ? Date.now() + data.expires_in * 1000 : undefined,
      tokenType: data.token_type || 'Bearer',
    };
  }

  // Check if the MCP server requires OAuth
  async checkAuthRequired(): Promise<boolean> {