How to Broadcast Todoist Task Completions in Slack with Zapier

zapier.com > Dashboard > Create Zap

Create a new Zap in Zapier

Log into zapier.com and click the orange 'Create Zap' button in the left sidebar. The Zap editor opens in a two-column layout — the left panel shows your step list, and the right panel shows configuration for the selected step. You'll build this Zap in order: trigger first, then action. Give your Zap a name at the top — something like 'Todoist Completions → Slack' keeps it easy to find later.

1. 1Log into zapier.com
2. 2Click 'Create Zap' in the left sidebar
3. 3Click the name field at the top and type 'Todoist Completions → Slack'
4. 4Click the Trigger step in the left panel to begin setup

Zap Editor > Trigger > App & Event

Set Todoist as the trigger app

In the right panel under 'Trigger', click the 'App' search box and type 'Todoist'. Select Todoist from the results — you'll see the official app with the red icon. Next, click the 'Event' dropdown and select 'Completed Task'. This is an instant trigger backed by Todoist's webhook system, so Zapier won't poll on a schedule — it fires within seconds of a task being checked off.

1. 1Click the 'App' search field in the Trigger panel
2. 2Type 'Todoist' and select the result with the red checkmark icon
3. 3Click the 'Event' dropdown
4. 4Select 'Completed Task'
5. 5Click 'Continue'

Zap Editor > Trigger > Account

Connect your Todoist account

Click 'Sign in to Todoist'. A popup opens asking you to authorize Zapier. Log in with the Todoist account that owns or has access to the projects you want to monitor. After authorizing, the popup closes and Zapier shows your account email in the 'Account' field. If you manage multiple Todoist workspaces, confirm the correct account is selected before continuing.

1. 1Click 'Sign in to Todoist'
2. 2Log in with your Todoist credentials in the popup
3. 3Click 'Allow' to grant Zapier access
4. 4Confirm your account email appears in the Account field
5. 5Click 'Continue'

Zap Editor > Trigger > Set up trigger

Configure the Todoist trigger filter

After connecting, Zapier shows a 'Project' dropdown under Trigger configuration. You can leave this set to 'All Projects' to catch every completed task across your workspace, or select a specific project to narrow the broadcast to one team's work. If you pick a specific project, only tasks completed inside that project will trigger the Zap. Choose 'All Projects' for now — you can add a Zapier Filter step later if you need to exclude certain projects.

1. 1In the 'Project' dropdown, select 'All Projects' or choose a specific project name
2. 2Click 'Continue'

Zap Editor > Trigger > Test trigger

Test the Todoist trigger

Click 'Test trigger'. Zapier pulls in a recently completed task from your Todoist account to use as sample data. If no tasks have been completed recently, you'll need to open Todoist, check off any task, then return to Zapier and click 'Test trigger' again. Look at the returned sample — you should see fields like task content, project name, completed date, and the assignee. Verify the data looks real and comes from the right project before moving on.

1. 1Click 'Test trigger'
2. 2Review the sample data fields returned
3. 3Confirm 'Content' shows the task name and 'Project' shows the correct project
4. 4Click 'Continue with selected record'

Zap Editor > Action > App & Event

Add Slack as the action app

Click the '+' icon below the trigger step to add an action. In the right panel, search for 'Slack' and select it. For the event, select 'Send Channel Message' — this posts a public message to a channel, which is what stakeholders will see. Do not select 'Send Direct Message' unless you want individual DMs instead of a shared channel broadcast.

1. 1Click the '+' icon below the Trigger step
2. 2Type 'Slack' in the app search field
3. 3Select Slack from the results
4. 4Click the 'Event' dropdown and select 'Send Channel Message'
5. 5Click 'Continue'

Zap Editor > Action > Account

Connect your Slack workspace

Click 'Sign in to Slack'. A popup opens and shows a list of workspaces your Slack account belongs to. Select the correct workspace from the dropdown, then click 'Allow' to grant Zapier permission to post messages. Once connected, the popup closes and your workspace name appears in the Account field. If the Zap needs to post to a workspace where you're not an admin, you still don't need admin rights — posting to channels only requires standard member access.

1. 1Click 'Sign in to Slack'
2. 2Select the correct workspace from the dropdown in the popup
3. 3Click 'Allow' to authorize Zapier
4. 4Confirm the workspace name appears in the Account field
5. 5Click 'Continue'

Zap Editor > Action > Set up action

Configure the Slack message

This is where you build the actual message. In the 'Channel' field, select the Slack channel where completions should post — type '#' to filter by channel name or search for it. In the 'Message Text' field, construct your message using Todoist data fields from the dropdown. Click inside the Message Text field, then click the purple data pill icon to insert dynamic values. A well-structured message covers: what was completed, which project it belongs to, and who completed it. See the field mapping section below for the exact fields to use.

1. 1Click the 'Channel' field and search for your target channel (e.g., #project-wins)
2. 2Click the 'Message Text' field
3. 3Type '✅ Task completed: ' then click the data pill icon
4. 4Select 'Content' from the Todoist fields list
5. 5Continue building: ' | Project: ' then insert 'Project Name'
6. 6Add ' | Completed by: ' then insert 'Assignee Name' or 'Author Name'

📬 New entry: {{1.name}}
Email: {{1.email}}
Details: {{1.description}}

Zap Editor > Action > Set up action > Bot settings

Set optional Slack message formatting

Scroll down in the action setup to find additional fields. Set 'Bot Name' to something like 'TaskBot' or your company name so it's clear messages are automated. Set 'Bot Icon' to an emoji like ':white_check_mark:' for visual consistency. Under 'Send as Bot' confirm it's set to 'Yes' — this posts as an app rather than your personal account, which keeps the message format clean and avoids confusion about who sent it.

1. 1Set 'Bot Name' to 'TaskBot' or your preferred name
2. 2Set 'Bot Icon' to ':white_check_mark:'
3. 3Confirm 'Send as Bot' is set to 'Yes'
4. 4Click 'Continue'

📬 New entry: {{1.name}}
Email: {{1.email}}
Details: {{1.description}}

Zap Editor > Action > Test action

Test the Slack action

Click 'Test action'. Zapier uses the sample Todoist data from Step 5 to send a real test message to your selected Slack channel right now. Open Slack and navigate to the channel — you should see the test message appear within 30 seconds. Read the message carefully: check that the task name, project, and assignee all display correctly. If any field is blank or shows an internal ID instead of readable text, return to the Message Text field in Step 8 and correct the data pill mapping.

1. 1Click 'Test action'
2. 2Open Slack and navigate to your target channel
3. 3Read the test message to confirm all fields display correctly
4. 4Return to Step 8 if any fields are blank or wrong
5. 5Click 'Continue' once the message looks correct

Zap Editor > Publish > Zap History

Turn on the Zap

Click 'Publish' in the top right of the Zap editor. Zapier shows a confirmation dialog — click 'Publish & Turn On'. The Zap is now live. Go to Todoist and complete any task to trigger a real run. Return to Slack within 90 seconds and you should see the announcement in your channel. Check the Zap History page (left sidebar > Zap History) after the first real run to confirm it shows 'Success' and the correct data was passed through.

1. 1Click 'Publish' in the top right corner
2. 2Click 'Publish & Turn On' in the confirmation dialog
3. 3Complete a task in Todoist to trigger the first real run
4. 4Check #your-channel in Slack within 90 seconds
5. 5Navigate to zapier.com > Zap History to confirm the run shows 'Success'

This Code by Zapier step runs between the Todoist trigger and the Slack action. Paste it into a 'Code by Zapier' step (choose 'Run Javascript'), add it as Step 2 in your Zap, and map its output fields into the Slack message instead of the raw Todoist fields. It formats the timestamp into a readable date and maps Todoist priority numbers to emoji flags so your Slack message is immediately readable without any manual lookup.

// Code by Zapier — paste into a 'Run Javascript' step between Todoist trigger and Slack action
// Input data from Todoist trigger:
const content = inputData.content || 'Unnamed task';

// Code by Zapier — paste into a 'Run Javascript' step between Todoist trigger and Slack action
// Input data from Todoist trigger:
const content = inputData.content || 'Unnamed task';
const projectName = inputData.project_name || 'No project';
const assigneeName = inputData.assignee_name || inputData.author_name || 'Unknown';
const completedAt = inputData.completed_at || '';
const priority = inputData.priority || '4';
const taskUrl = inputData.url || '';

// Map Todoist priority (1=urgent, 4=none) to emoji
const priorityMap = { '1': '🔴', '2': '🟠', '3': '🔵', '4': '⚪' };
const priorityEmoji = priorityMap[priority] || '⚪';

// Format timestamp to human-readable date
let formattedDate = '';
if (completedAt) {
  const d = new Date(completedAt);
  formattedDate = d.toLocaleDateString('en-US', { weekday: 'short', month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' });
}

// Build the Slack message string
const slackMessage = [
  `✅ *${content}*`,
  `📁 Project: ${projectName}`,
  `👤 Completed by: ${assigneeName}`,
  formattedDate ? `🕐 ${formattedDate}` : null,
  priorityEmoji !== '⚪' ? `${priorityEmoji} Priority task` : null,
  taskUrl ? `🔗 ${taskUrl}` : null
].filter(Boolean).join('\n');

output = [
  {
    slackMessage: slackMessage,
    priorityEmoji: priorityEmoji,
    formattedDate: formattedDate,
    assigneeDisplay: assigneeName
  }
];