# 7. Core Workflows
This sequence diagram illustrates a typical "Create Task" workflow, showing how a request flows through the system from the client to the external API and back.
```mermaid
sequenceDiagram
participant ClientApp as Client App (IDE)
participant CoreServer as MCP Server (stdio)
participant TaskTools as TaskTools Component
participant LunaTaskClient as LunaTaskClient
participant LunaTaskAPI as LunaTask API
ClientApp->>+CoreServer: Sends MCP `create_task` request via stdio
CoreServer->>+TaskTools: Forwards request to `create_task` tool
TaskTools->>+LunaTaskClient: Calls `create_task` method with validated data
LunaTaskClient->>+LunaTaskAPI: Makes authenticated POST /v1/tasks request
LunaTaskAPI-->>-LunaTaskClient: Returns success response with new task data
LunaTaskClient-->>-TaskTools: Returns success result to tool
TaskTools-->>-CoreServer: Formats success into MCP response
CoreServer-->>-ClientApp: Sends MCP success response via stdio
```
---
## Create Note Workflow
```mermaid
sequenceDiagram
participant ClientApp as Client App (IDE)
participant CoreServer as MCP Server (stdio)
participant NotesTools as NotesTools Component
participant LunaTaskClient as LunaTaskClient
participant LunaTaskAPI as LunaTask API
ClientApp->>+CoreServer: Sends MCP `create_note` request via stdio
CoreServer->>+NotesTools: Forwards request to `create_note` tool
NotesTools->>+LunaTaskClient: Calls `create_note` with validated payload
LunaTaskClient->>+LunaTaskAPI: Makes authenticated POST /v1/notes request
alt Duplicate detected (204 No Content)
LunaTaskAPI-->>-LunaTaskClient: Returns empty body
LunaTaskClient-->>-NotesTools: Returns `None`
NotesTools-->>-CoreServer: Formats duplicate success response
else Note created
LunaTaskAPI-->>-LunaTaskClient: Returns wrapped note payload
LunaTaskClient-->>-NotesTools: Returns `NoteResponse`
NotesTools-->>-CoreServer: Formats success response with note_id
end
CoreServer-->>-ClientApp: Sends MCP response via stdio
```
---
## Update Note Workflow
```mermaid
sequenceDiagram
participant ClientApp as Client App (IDE)
participant CoreServer as MCP Server (stdio)
participant NotesTools as NotesTools Component
participant LunaTaskClient as LunaTaskClient
participant LunaTaskAPI as LunaTask API
ClientApp->>+CoreServer: Sends MCP `update_note` request (note_id, optional fields)
CoreServer->>+NotesTools: Forwards request to `update_note` tool
NotesTools->>NotesTools: Validates at least one field provided
NotesTools->>NotesTools: Validates date_on format if provided
alt Validation fails
NotesTools-->>-CoreServer: Returns validation_error payload
CoreServer-->>-ClientApp: Emits MCP error response via stdio
else Valid update
NotesTools->>+LunaTaskClient: Calls update_note with NoteUpdate
LunaTaskClient->>+LunaTaskAPI: Makes authenticated PUT /v1/notes/{id} request
alt Note not found (404)
LunaTaskAPI-->>-LunaTaskClient: Returns 404 error
LunaTaskClient-->>-NotesTools: Raises LunaTaskNotFoundError
NotesTools-->>-CoreServer: Returns not_found_error payload
CoreServer-->>-ClientApp: Emits MCP error response via stdio
else Note updated successfully
LunaTaskAPI-->>-LunaTaskClient: Returns wrapped note payload
LunaTaskClient-->>-NotesTools: Returns NoteResponse
NotesTools-->>-CoreServer: Formats success payload with note_id
CoreServer-->>-ClientApp: Sends MCP success response via stdio
end
end
```
---
## Delete Note Workflow
```mermaid
sequenceDiagram
participant ClientApp as Client App (IDE)
participant CoreServer as MCP Server (stdio)
participant NotesTools as NotesTools Component
participant LunaTaskClient as LunaTaskClient
participant LunaTaskAPI as LunaTask API
ClientApp->>+CoreServer: Sends MCP `delete_note` request (note_id)
CoreServer->>+NotesTools: Forwards request to `delete_note` tool
NotesTools->>NotesTools: Validates note_id not empty/whitespace
alt Validation fails
NotesTools-->>-CoreServer: Returns validation_error payload
CoreServer-->>-ClientApp: Emits MCP error response via stdio
else Valid note_id
NotesTools->>+LunaTaskClient: Calls delete_note with note_id
LunaTaskClient->>+LunaTaskAPI: Makes authenticated DELETE /v1/notes/{id} request
alt Note not found (404)
LunaTaskAPI-->>-LunaTaskClient: Returns 404 error
LunaTaskClient-->>-NotesTools: Raises LunaTaskNotFoundError
NotesTools-->>-CoreServer: Returns not_found_error payload
CoreServer-->>-ClientApp: Emits MCP error response via stdio
else Note deleted successfully
LunaTaskAPI-->>-LunaTaskClient: Returns wrapped note payload with deleted_at
LunaTaskClient-->>-NotesTools: Returns NoteResponse
NotesTools-->>-CoreServer: Formats success payload with deleted_at
CoreServer-->>-ClientApp: Sends MCP success response via stdio
end
end
```
---
## Daily Journal Workflow
```mermaid
sequenceDiagram
participant ClientApp as Client App (IDE)
participant CoreServer as MCP Server (stdio)
participant JournalTools as JournalTools Component
participant LunaTaskClient as LunaTaskClient
participant LunaTaskAPI as LunaTask API
ClientApp->>+CoreServer: Sends MCP `create_journal_entry` request (date_on, name, content)
CoreServer->>+JournalTools: Forwards request to `create_journal_entry` tool
JournalTools->>JournalTools: Validates ISO-8601 `date_on` input
alt Invalid date format
JournalTools-->>-CoreServer: Returns validation_error payload
CoreServer-->>-ClientApp: Emits MCP error response via stdio
else Valid date
JournalTools->>+LunaTaskClient: Calls create_journal_entry with JournalEntryCreate
LunaTaskClient->>+LunaTaskAPI: Makes authenticated POST /v1/journal_entries request
LunaTaskAPI-->>-LunaTaskClient: Returns wrapped journal entry payload
LunaTaskClient-->>-JournalTools: Returns JournalEntryResponse
JournalTools-->>-CoreServer: Formats success payload with journal_entry_id
CoreServer-->>-ClientApp: Sends MCP success response via stdio
end
```
---
