VB.NET Requires Chilkat v11.7.0+
Box: Create a Project Folder, Upload, Tag, and Link a Document

Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. Resolve the parent documents folder by name, create a new project folder, upload a document, apply pre-existing projectDocument metadata, and create a collaborators-only link. Creation outputs remain cached for subsequent operations; the engine resolves the enterprise scope only when metadata needs it. Multipart formatting and deliberate writes remain explicit.
See the Box API guide for setup and the complete workflow.
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Dim success As Boolean = False

'  Requires Chilkat 11.7.0 or later and a previously unlocked Chilkat bundle.
'  See Global Unlock Sample.
'  Guide: Box API Guide.

success = False

'  BEGIN ONE-TIME SETUP
'  This block is repeated so each published example can run on its own.
'  In an application, run the setup example once and pass the SAME curl object
'  to operation code below. Do not recreate it for every operation.
'  See Reusable Box HttpCurl Setup.
Dim curl As New Chilkat.HttpCurl
curl.SetVar("access_token","BOX_ACCESS_TOKEN")
curl.SetVar("parent_name","/")
'  Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id","0")
Dim setupCommand As New Chilkat.StringBuilder
Dim setupReplacements As Integer

'  Register findParent; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findParent",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register findFolder; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findFolder",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register findFile; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findFile",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register findDestination; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("findDestination",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register getFileDetails; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("getFileDetails",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register getEnterprise; registration sends no request.
setupCommand.SetString("curl -X GET ""https://api.box.com/2.0/users/me?fields=enterprise"" -H ""Authorization: Bearer ACCESS_TOKEN""")
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"))
success = curl.AddFunction("getEnterprise",setupCommand.GetAsString())
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
'  when extracting each output, using the current value at that time.
success = curl.AddOutput2("findParent","entries","name","{{parent_name}}",True,"id","parent_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findFolder","entries","name","{{folder_name}}",True,"id","folder_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findFile","entries","name","{{file_name}}",True,"id","file_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findDestination","entries","name","{{destination_name}}",True,"id","destination_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getFileDetails","file_version.id","file_version_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getFileDetails","sha1","file_sha1")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getEnterprise","enterprise.id","enterprise_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

'  END ONE-TIME SETUP
'  The name lookups below assume each listing fits in one page (1000 items).
'  Parent and destination names select root children; folder_name selects a child
'  of parent_name. "/" selects the root parent. These are not arbitrary paths.

'  BEGIN OPERATION -- keep the configured object when reusing it.
'  Inputs are names. Retain cached IDs when the selected names have not changed.
Dim parentName As String = "documents"
If ((curl.GetVar("parent_name") <> parentName) Or ((parentName = "/") And (curl.VarDefined("parent_id") = False))) Then
    curl.SetVar("parent_name",parentName)
    curl.ClearVar("parent_id")
    curl.ClearVar("folder_id")
    curl.ClearVar("file_id")
    curl.ClearVar("file_version_id")
    curl.ClearVar("file_sha1")
    If (parentName = "/") Then
        curl.SetVar("parent_id","0")
    End If

End If

curl.SetVar("new_folder_name","Project CUST-1001")
'  This workflow creates a new folder. A 409 stops the example; it does not
'  silently reuse a same-named folder. Retain printed IDs if a later step fails.
curl.ClearTargetOutput("*")
curl.ClearVar("folder_id")
curl.AddTargetOutput("id","folder_id")
Dim authorizedCommand1 As New Chilkat.StringBuilder
authorizedCommand1.SetString("curl -X POST ""https://api.box.com/2.0/folders"" -H ""Authorization: Bearer {{access_token}}"" -H ""Content-Type: application/json"" -d '{""name"":""{{new_folder_name}}"",""parent"":{""id"":""{{parent_id}}""}}'")
Dim headerReplacement1 As Integer = authorizedCommand1.Replace("{{access_token}}",curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand1.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 201)) Then
    Debug.WriteLine("Box request failed. HTTP status: " & curl.StatusCode)
    Debug.WriteLine("Failure reason: " & curl.FailReason)
    Debug.WriteLine(curl.ResponseBodyStr)
    Exit Sub
End If

If (curl.VarDefined("!") <> True) Then
    Debug.WriteLine("Expected response fields are missing.")
    Exit Sub
End If

Debug.WriteLine("Created folder: " & curl.GetVar("folder_id"))
'  Resolve the multipart attributes field before passing the command to HttpCurl.
'  Box folder IDs come from configuration or a previous API response.
Dim uploadCommand As New Chilkat.StringBuilder
Dim authorizedCommand2 As New Chilkat.StringBuilder
authorizedCommand2.SetString("curl -X POST ""https://upload.box.com/api/2.0/files/content"" -H ""Authorization: Bearer {{access_token}}"" -F 'attributes={""name"":""invoice.pdf"",""parent"":{""id"":""{{folder_id}}""}}' -F ""file=@qa_data/pdf/invoice.pdf;type=application/pdf""")
Dim headerReplacement2 As Integer = authorizedCommand2.Replace("{{access_token}}",curl.GetVar("access_token"))
uploadCommand.SetString(authorizedCommand2.GetAsString())
Dim replacements As Integer = uploadCommand.Replace("{{folder_id}}",curl.GetVar("folder_id"))
curl.ClearTargetOutput("*")
curl.ClearVar("file_id")
curl.AddTargetOutput("entries[0].id","file_id")
success = curl.DoYourThing(uploadCommand.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 201)) Then
    Debug.WriteLine("Box request failed. HTTP status: " & curl.StatusCode)
    Debug.WriteLine("Failure reason: " & curl.FailReason)
    Debug.WriteLine(curl.ResponseBodyStr)
    Exit Sub
End If

If (curl.VarDefined("!") <> True) Then
    Debug.WriteLine("Expected response fields are missing.")
    Exit Sub
End If

Debug.WriteLine("Uploaded file: " & curl.GetVar("file_id"))
curl.ClearTargetOutput("*")
Dim authorizedCommand3 As New Chilkat.StringBuilder
authorizedCommand3.SetString("curl -X POST ""https://api.box.com/2.0/files/{{file_id}}/metadata/enterprise_{{enterprise_id}}/projectDocument"" -H ""Authorization: Bearer {{access_token}}"" -H ""Content-Type: application/json"" -d '{""customerId"":""CUST-1001"",""status"":""received""}'")
Dim headerReplacement3 As Integer = authorizedCommand3.Replace("{{access_token}}",curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand3.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 201)) Then
    Debug.WriteLine("Box request failed. HTTP status: " & curl.StatusCode)
    Debug.WriteLine("Failure reason: " & curl.FailReason)
    Debug.WriteLine(curl.ResponseBodyStr)
    Exit Sub
End If

curl.ClearTargetOutput("*")
curl.ClearVar("shared_url")
curl.AddTargetOutput("shared_link.url","shared_url")
Dim authorizedCommand4 As New Chilkat.StringBuilder
authorizedCommand4.SetString("curl -X PUT ""https://api.box.com/2.0/files/{{file_id}}?fields=id,shared_link"" -H ""Authorization: Bearer {{access_token}}"" -H ""Content-Type: application/json"" -d '{""shared_link"":{""access"":""collaborators""}}'")
Dim headerReplacement4 As Integer = authorizedCommand4.Replace("{{access_token}}",curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand4.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 200)) Then
    Debug.WriteLine("Box request failed. HTTP status: " & curl.StatusCode)
    Debug.WriteLine("Failure reason: " & curl.FailReason)
    Debug.WriteLine(curl.ResponseBodyStr)
    Exit Sub
End If

If (curl.VarDefined("!") <> True) Then
    Debug.WriteLine("Expected response fields are missing.")
    Exit Sub
End If

Debug.WriteLine("Document link: " & curl.GetVar("shared_url"))
'  The link is for existing collaborators. Invite users separately when needed.
'  ClearTargetOutput removes old extraction rules; it does not clear existing IDs.
curl.SetVar("folder_name",curl.GetVar("new_folder_name"))
curl.SetVar("file_name","invoice.pdf")
curl.ClearVar("file_version_id")
curl.ClearVar("file_sha1")