Visible assumptions
Keeps workflow volume, operations per run, unit rates and fixed fees in one reviewable local plan.
Day 054 / n8n / Cost Planning
Automation Cost Estimator
/ Overview
A dependency-free Python CLI that turns explicit workflow-volume and unit-rate assumptions into a transparent monthly automation cost estimate.
Automation expenses can combine platform subscriptions, workflow executions, per-operation charges and fixed service fees. A quick estimate should make those assumptions visible without reading billing accounts or implying that a forecast is an invoice.
/ Provided servicesClear thinking.
Clear thinking.
Practical delivery.
Itemized estimates
Shows run, operation and fixed costs for every workflow before calculating the monthly total.
Honest boundaries
Labels results as estimates and requires current provider rates to be verified outside the tool.
/ Solution
Automation Cost Estimator validates a bounded local JSON plan, expands daily runs into a configurable monthly window, calculates run and operation charges with decimal arithmetic, and separates variable costs from fixed costs. It produces readable or JSON output. It does not connect to n8n, inspect accounts, fetch live prices or guarantee billed totals; supplied rates must be checked against current provider pricing.
/ Impact
Monthly workflow-run estimates
Operation-volume estimates
Per-workflow cost breakdowns
Variable and fixed subtotals
Explicit decimal money rounding
Bounded defensive JSON validation
Text and JSON reports
Twelve standard-library tests
Python standard library
Argparse, JSON and Decimal provide a dependency-free local CLI with no remote account access.
Defensive validation
Rejects duplicate keys or workflow names, negative and non-finite values, undeclared fields and oversized plans.
Unittest
Twelve tests cover cost arithmetic, rounding, defaults, invalid plans, duplicate JSON keys and serializable output.