$ stack repl

>>> import Web.Todoist
>>> let config = newTodoistConfig "your-api-token-here"
>>> result <- todoist config getAllProjects
>>> case result of
      Left err -> print err
      Right projects -> mapM_ print projects

#!/usr/bin/env stack
-- stack --resolver lts-24.7 script --package todoist-sdk --package text

{-# LANGUAGE OverloadedStrings #-}

import Web.Todoist

main :: IO ()
main = do
    let config = newTodoistConfig "your-api-token-here"
    result <- todoist config $ do
        let newProj = runBuilder (createProjectBuilder "My Haskell Project")
                      (withDescription "Learning Haskell SDK" <> withViewStyle Board)
        project <- addProject newProj
        let newTask = runBuilder (newTaskBuilder "Read documentation")
                      (withProjectId (_id project) <> withPriority 2)
        task <- createTask newTask
        tasks <- getTasks taskParamBuilder
        pure (project, task, tasks)
    case result of
        Left err -> putStrLn $ "Error: " ++ show err
        Right (proj, task, tasks) -> do
            putStrLn $ "Created project: " ++ show (_name proj)
            putStrLn $ "Created task: " ++ show (_content task)
            putStrLn $ "Total tasks: " ++ show (length tasks)

chmod +x example.hs
./example.hs

import Web.Todoist

let config = newTodoistConfig "your-api-token"

-- Fetch all projects
result <- todoist config getAllProjects

-- Create a new project
let newProject = runBuilder (createProjectBuilder "Shopping List")
                 (withColor "blue" <> withViewStyle List <> withIsFavorite True)
project <- todoist config (addProject createProjectBuilder)

-- Update a project
let update = runBuilder emptyProjectUpdate (withName "Updated Name")
updated <- todoist config (updateProject update projectId)

-- Delete a project
todoist config (deleteProject projectId)

-- Create a task with a due date
let task = runBuilder (newTaskBuilder "Buy milk")
           (withProjectId "project-123"
            <> withDueString "tomorrow"
            <> withPriority 3
            <> withLabels ["grocery", "urgent"])
result <- todoist config (createTask task)

-- Fetch tasks with filters
let params = TaskParam
    { project_id = Just "project-123"
    , filter = Nothing
    , label_id = Nothing
    , cursor = Nothing
    , limit = Nothing
    }
tasks <- todoist config (getTasks params)

-- Complete a task
todoist config (closeTask taskId)

-- Update a task
let update = runBuilder updateTaskBuilder (withContent "Buy 2% milk")
updated <- todoist config (updateTask update taskId)

-- Add a comment to a task
let comment = runBuilder (newCommentBuilder "Don't forget organic!")
              (withTaskId "task-456")
result <- todoist config (addComment comment)

-- Retrieve all comments for a project
let params = CommentParam
    { project_id = Just "project-123"
    , task_id = Nothing
    , cursor = Nothing
    , limit = Nothing
    , public_key = Nothing
    }
comments <- todoist config (getComments params)

result <- todoist config (getProject projectId)
case result of
    Left BadRequest -> putStrLn "Invalid project ID"
    Left Unauthorized -> putStrLn "Check your API token"
    Left NotFound -> putStrLn "Project not found"
    Left (HttpError msg) -> putStrLn $ "HTTP error: " ++ msg
    Right project -> print project