Recipe 04, Approval-routed purchase order

Goal: a form submission for a purchase order is auto-approved if under $1 000, routes to a finance approver if higher, and (on approval) records the PO to a database.

Difficulty: Intermediate · Time: ~30 minutes · Connectors: Form trigger, Database (Postgres / similar), optional Slack

Prerequisites

A database credential (Postgres / MySQL / etc.) with a purchase_orders table:

CREATE TABLE purchase_orders (
  id          serial PRIMARY KEY,
  requester   text,
  vendor      text,
  amount      numeric,
  description text,
  status      text,
  approved_by text,
  created_at  timestamp DEFAULT now()
);

One workspace user who will act as the finance approver. (Or use a public approval link for an external CFO.)

Finished workflow

┌──────────┐    ┌────────┐
│   Form   │───▶│   If   │ amount > 1000
│ Trigger  │    └───┬────┘
└──────────┘        │
               true ┤              false
                    ▼               ▼
              ┌──────────┐    ┌────────────┐
              │ Approval │    │ DB: insert │
              │  finance │    │  (status   │
              └────┬─────┘    │ = approved)│
                   │ approved └────┬───────┘
                   ▼               │
              ┌────────────┐       │
              │ DB: insert │       │
              │  (status   │       │
              │ = approved)│       │
              └─────┬──────┘       │
                    │              │
                    └──────┬───────┘
                           ▼
                     ┌──────────┐
                     │  Email:  │
                     │  receipt │
                     └──────────┘

Step-by-step

1. Form trigger

Replace Start with Form Trigger:

Fields:

requester (text, required)
vendor (text, required)
amount (number, required, min 0)
description (textarea)

Visibility: Authenticated (so the requester is identified). Or Public if you want anyone to submit.

2. If: amount > 1 000

Add an If node connected to the Form Trigger.

Condition:

value1: {{ $trigger.amount }}
operator: greaterThan
value2: 1000

3. Approval branch (true)

From the true port, add an Approval node:

Title: Purchase order needs your approval

Message:

{{ $trigger.requester }} is requesting **${{ $trigger.amount }}** for {{ $trigger.vendor }}.

Reason: {{ $trigger.description }}

Data to show: requester, vendor, amount, description
Approvers: your finance approver user
Approval policy: Any one
Timeout: 72h, action escalate to: another approver

4. DB insert (both branches)

From the Approval's approved port AND from the If's false port, both connect to a single Database node:

Operation: Insert
Table: purchase_orders

Data:

requester:    {{ $trigger.requester }}
vendor:       {{ $trigger.vendor }}
amount:       {{ $trigger.amount }}
description:  {{ $trigger.description }}
status:       approved
approved_by:  {{ $node["Approval"].json.approval.approvedBy[0] || "auto" }}

(The || shorthand here is conceptual, implement the fallback via a Set node or Code node as needed.)

5. Email the requester

After Database, add an Email node:

To: {{ $trigger.requester }}
Subject: PO #${{ $node["Database"].json.id }} approved
Body: a short HTML confirmation.

6. Reject branch (optional)

From Approval's rejected port, add another Email node informing the requester that their PO was declined, including the approval comment.

7. Save and activate

Try it

Share the form URL with yourself. Submit a request for $100.
- Workflow auto-approves; PO appears in the database; you get the confirmation email.
Submit for $5 000.
- Workflow pauses at Approval.
- Approver gets an in-app notification; navigates to /approvals and approves.
- PO inserts; email arrives.

Variations

Multi-party approval

For very large POs (> $50k), route through a Switch instead of an If to a second Approval node with multiple approvers and All approvers policy. See Multi-party approvals.

Public approval

Replace the named approver with a public approval link → email to your CFO who doesn't use Flero. See Public approval links.

Slack notification on submission

Add a Slack node between Form Trigger and If, posting to #purchasing with the request details.

Attach a contract PDF

Add a file field to the Form Trigger. Save the file to S3 (File Operations node) and include the link in the database row and email.

Troubleshooting

Symptom	Likely cause	Fix
Form submits but workflow doesn't fire	Workflow not active	Set status to `active`
Approval never reaches the finance user	They have notifications off	They enable approval notifications in Settings → Notifications
`approved_by` is null on auto-approved POs	The expression fallback doesn't work	Use a Set node to compute it explicitly
Database write fails with "amount: invalid type"	Form amount comes through as string	Use Data Transform `convert` to cast to number before the Database node

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