Justworks Model Context Protocol (MCP)

This article is about Justworks PEO and Payroll. What product am I using?

What is the Justworks MCP?

The Justworks MCP lets you access your Justworks data directly from the AI tools you already use, like Claude or ChatGPT. Ask a question in natural language and get a real answer from your Justworks account, right where you're working.

MCP (Model Context Protocol) is an open standard that lets AI tools connect securely to external platforms. The Justworks MCP is built on this standard, so Justworks can show up in your workflow instead of asking you to leave it.

What can I do with it?

With the Justworks MCP connected, you can ask about your Justworks data in plain language:

• Headcount & team data — "How many active employees do we have?" or "Show me employees hired in the last 90 days"
• Payroll & paystubs — "What did we run in payroll last month?" or "Show me the paystub for [employee name]"
• Time off — "What's the PTO balance for [employee name]?" or "Show me all open time-off requests"
• Deductions — "What deduction types do we have set up?"
• Reports — "Summarize headcount by department" or "Break down time-off usage this quarter"

This release gives admins read-only access to Justworks data — member rosters, payroll history, paystubs, deductions, and time off — that you can use within your AI tool to build reports and charts, automate workflows, and connect to other apps.

Who can use it?

The Justworks MCP is available to Justworks account administrators. You'll need access to an MCP-compatible AI tool such as Claude or ChatGPT to get started.

Connecting to the Justworks MCP Server

Choose your platform below for setup instructions.

Claude Code

Step 1: Run this command in your terminal (one-time setup):

Step 2: Start a new Claude Code session, type /mcp, select Justworks, and click Authenticate.

Step 3: This will open the OAuth login flow and you can sign in with your Justworks credentials. 

Once authenticated, Justworks tools are available for all sessions.

Claude Desktop

Step 1: In the left toolbar, click Customize → Connectors → the + icon.

Step 2: Enter Justworks as the name and https://mcp.justworks.com as the Remote MCP server URL, then save.

Step 3: Justworks will appear in your connectors list.

Step 4: Click on Justworks, click the Connect button, and complete the OAuth login flow by signing in with your Justworks credentials.

Justworks tools are now available in your Claude Desktop sessions.

ChatGPT (Web)

Step 1: Enable Developer Mode. Go to Settings → Apps → Advanced settings and toggle Developer Mode on.

Step 2: Still in Settings → Apps → Advanced settings, click Create app.

Step 3: Enter Justworks as the name, add a description if you'd like, and under Connection, make sure it's toggled to Server URL.

Step 4: Enter https://mcp.justworks.com in the URL field, set authentication to OAuth, and save.

Step 5: Complete the OAuth login flow when prompted.

Step 6: In a new chat, click +, then More, and make sure Justworks is selected.

Other AI Tools

For any other AI tool, check the tool's help center to see if it supports apps, plugins, or MCP servers. Most will allow you to add a custom URL. If asked, the authentication method for the Justworks MCP server is OAuth.

Server URL: https://mcp.justworks.com

Usage Guidelines

• Use an isolated session: Run Justworks as the only MCP server in your AI session. Connecting multiple MCP servers at once can cause unpredictable behavior and potential data leakage.
• Use trusted AI clients only: Connect through established platforms like Claude or ChatGPT.
• Confirm data access before it runs: Disable automatic tool execution settings so you are prompted to approve each data request before it runs.
• Verify AI outputs before acting: Treat AI-generated responses as a starting point. AI models can misinterpret data, so always confirm accuracy before making decisions.
• Opt out of model training: This helps ensure your company's data stays private.

Troubleshooting

OAuth flow isn't completing

• Verify you're using the Justworks credentials associated with your account.
• Try restarting the OAuth flow if the connection fails.
• Clear browser cookies and try again if the issue persists.

Connector isn't active after setup

• Click Connect on the connector in your list and confirm it shows as connected before starting a chat.
• For ChatGPT, make sure Justworks is enabled as a source.

Plan not supported

• Claude Desktop custom connectors require a Pro or above plan.
• ChatGPT MCP support requires a Pro, Enterprise, or Edu plan.
• Some IT teams don't allow custom MCP servers, so check with your administrator if you're having trouble finding where to add the MCP server.

Authentication errors

• Ensure your Justworks account is active and that you have permission to access the MCP in your organization.
• If issues persist, contact us via the dedicated Slack channel.

Security & Privacy

The Justworks MCP uses OAuth 2.0 authentication to act as a secure bridge between your AI tool and your Justworks account, in accordance with the Justworks Privacy Policy. Data transfers are encrypted and limited to the connection between Justworks and your AI tool. Connection to your AI tool is ongoing until you disconnect it. Justworks does not guarantee and is not responsible for your AI tool’s privacy or security.

Disclaimer

This material has been prepared for informational purposes only, and is not intended to provide, and should not be relied on for, business, legal or tax advice. If you have any legal or tax questions regarding this content or related issues, then you should consult with your professional legal or tax advisor.