Submit and approve employee expenses with Odoo, Slack, and Gmail

Quick overview

This workflow receives employee expense submissions via a webhook, validates the payload, creates an expense in Odoo, and immediately acknowledges the request. It then sends a Slack approval form to managers and, based on the decision, updates the Odoo expense status and notifies the employee via Gmail.

How it works

1. Receives an expense submission via a POST webhook and normalizes fields like employee, vendor, amount, category, description, and receipt details.
2. Validates required fields and returns a 400 JSON response if the submission is incomplete or invalid.
3. Looks up the employee in Odoo (hr.employee) and returns a 404 JSON response if no matching employee record is found.
4. Looks up the expense category in Odoo (product.product) and creates an expense record in Odoo (hr.expense), returning a 202 JSON response with the created expense ID.
5. Posts a Slack message to the #expense-approvals channel with a custom approval form and waits up to two days for a manager decision.
6. If approved, updates the Odoo expense state to approved and emails the employee via Gmail; otherwise, marks the expense refused with the manager comment and emails the employee to resubmit.

Setup

1. Create an Odoo API credential with access to hr.employee, product.product, and hr.expense, and verify your Odoo schema supports the mapped fields (for example, unit_amount and payment_mode).
2. Add a Slack credential with permission to post to #expense-approvals (or change the channel) and use interactive messages to collect the approval decision and comment.
3. Add a Gmail OAuth credential and ensure the workflow can email employees using the submitted employeeEmail field.
4. Copy the production webhook URL and configure your expense form/app to POST the expected JSON fields (employeeName/employeeEmail, vendor, amount, currency, category, description, and receiptUrl).