Is there a free grail price API?

Yes. Reads on the /v1 price database are keyless and rate-limited, and a free account mints an API key. Paid plans add call volume and resale depth.

Can an AI agent connect over MCP?

Yes. Atelier runs a typed MCP server at /mcp over Streamable HTTP, plus /openapi.json and /llms.txt for tool-calling models. Setup is in the API docs.

Which marketplaces does the grail price data cover?

eBay, Grailed & StockX, reconciled into one lowest live price per grail with the full cross-source offer list and a Buy/Hold/Wait verdict.

Atelier data API

The live grail price API, built for AI agents

One reconciled dataset: the lowest live price for every grail across eBay, Grailed & StockX, with the full cross-source offer list and a Buy/Hold/Wait verdict. Keyless to read. One request to try.

See plans and start free → Read the API docs

How an AI agent connects

Four ways in, all live now. Pick whichever your client already speaks:

Keyless REST: GET /v1 returns the price database as JSON. No key, no signup, rate-limited.
MCP server: /mcp (Streamable HTTP): typed tools your MCP client connects to and calls live. Setup in the docs.
OpenAPI: /openapi.json describes the whole surface. Generate a client, or hand it to a tool-calling model.
llms.txt: /llms.txt is a plain-text map of the site and API, written to be read by models.

What's in the data

The lowest live price per grail, reconciled across eBay, Grailed & StockX.
The cross-source offer list behind every price, so an agent can cite where each number came from.
A Buy/Hold/Wait verdict per grail, computed from the live market spread.
On paid plans: higher call volume plus resale depth, up to the full resale curve.

Prices self-heal daily against marketplace anchors, so your agent can quote them with confidence.

Free to start, paid when you scale

Reads are keyless. A free account mints an API key. Paid plans add call volume plus deeper resale data, up to the full resale curve.

Ship the integration today. Keyless read now, free key in a minute, upgrade when your agent needs volume.

Get your free key → API reference