Harvest MCP Integration

Weldable's Harvest MCP integration gives your AI agents read and write access to your Harvest time tracking and invoicing data. Your agent can log time entries, query project budgets, pull utilization reports, and manage invoices through natural language. No more toggling between Harvest and your other tools to piece together project health.

Harvest has become one of the most popular MCP-connected tools in the time tracking space, with multiple open-source servers already available on GitHub. Weldable builds on this momentum by handling authentication, token refresh, and multi-integration chaining so your agent can combine Harvest data with Slack, Google Sheets, and other connected services.

Use cases

Automated timesheet reminders

Your agent checks Harvest at the end of each workday for team members who haven't logged any time. It sends a direct message in Slack reminding them to fill in their timesheets before the end of the week. On Friday afternoon, it runs a final check and sends a summary to the project manager listing who's up to date and who still has gaps.

Project budget monitoring

Your agent queries Harvest for all active projects and compares logged hours against the project budget. When a project crosses 80% of its hour budget, the agent notifies the project manager with the current burn rate and an estimate of when the budget will be exhausted at the current pace. This gives teams time to adjust scope or request additional budget before they hit the limit.

Client invoicing preparation

At the end of each billing cycle, your agent pulls all billable time entries from Harvest for a specific client, groups them by project and task, and generates a summary breakdown. It can create a draft invoice in Harvest or export the data to a Google Sheet for review before sending. The finance team gets a pre-built invoice instead of spending hours compiling entries manually.

Team utilization reporting

Your agent calculates utilization rates for each team member by comparing their logged hours against their capacity in Harvest. It generates a weekly report showing who's over-allocated, who has availability, and which projects are consuming the most resources. The report posts to your operations channel so managers can rebalance workloads before anyone burns out.

Expense tracking and categorization

Your agent monitors expense entries in Harvest and flags any that are missing categories or receipts. It groups expenses by project and client, calculates totals, and compares them against project budgets. At month end, it produces a categorized expense summary for the finance team.

How it works

Connect your Harvest account through Weldable's OAuth flow. Harvest uses OAuth 2.0, and Weldable manages the full token lifecycle including automatic refresh. Your agent authenticates with the scopes needed to read and write time entries, projects, clients, tasks, and invoices.

Once connected, describe what you need in plain English. Say "log 2 hours to the Acme website redesign project for today" or "show me all unbilled time entries for the past week" and Weldable maps your request to the correct Harvest API calls. Your agent handles the translation between project names and Harvest IDs behind the scenes.

Tips

Harvest's API uses account-level authentication. Each Harvest account has a unique Account ID that must be included in the request headers alongside the OAuth token. Weldable handles this automatically, but if you're troubleshooting, know that a missing Account ID causes authentication failures even with a valid token.

Time entries need both project and task IDs. When your agent logs time, it needs to specify both the project and the task within that project. Harvest doesn't accept time entries without a task assignment. Make sure your projects have tasks configured, or the agent won't be able to log hours.

Billable vs. non-billable defaults come from the project settings. Each project in Harvest has a default billable status. Your agent can override this per entry, but if you're seeing unexpected billing classifications, check the project-level defaults first.

Harvest rate limits are 100 requests per 15 seconds. This is generous for most workflows, but batch operations like pulling time entries for an entire team across a quarter can hit the ceiling. Your agent should paginate large requests and respect the Retry-After header if throttled.