Reach your costs from an API, an AI assistant or Shopify Sidekick

The API

The API is at https://api.cogsy.app, with an OpenAPI description at /openapi.json. It has 13 operations:

Area	What you can do
Shop	Read the shop and how much of the catalog has a cost
Variants	List variants with their costs, and list the cost rows that reach one variant
Lookup	Ask what a SKU or variant costs and what is in that number
Costs	Add a cost, import many by SKU, or void a row
Sources	Choose which source’s unit cost counts for a variant
Cost kinds	List the shop’s cost kinds and add one
Shopify	Write costs to Shopify’s cost per item
Sync	Start a catalog sync and read the latest one

The rules are the app’s own. The cost history is append-only: to change a cost you add a row, and to cancel one you void it. Writing costs to Shopify happens only when you call for it.

What people build with it

• A nightly job that imports the supplier’s price file with the date it takes effect.
• A purchasing tool that records the price on each order as a cost from that supplier.
• A spreadsheet or dashboard that reads total cost and margin per variant.

The MCP server

For AI assistants that speak the Model Context Protocol, the same operations are available at https://mcp.cogsy.app/mcp, one tool per API operation, using the same key.

Tools that only read are marked read-only. Voiding a cost and writing costs to Shopify are marked destructive, which is the signal assistants use to confirm with you first.

That makes requests like these possible in an assistant you already use:

• “Which variants have no unit cost?”
• “What does LT-OAT cost, and what is in that number?”
• “Add Supplier B’s quote of 20.90 for LT-OAT from 1 July.”

In Shopify Sidekick

Inside the Shopify admin, Sidekick can answer two questions from your Cogsy data:

• what a SKU costs and what that figure is made of;
• which variants have no unit cost.

Both are read-only.