Use Ghost Bakery from an AI assistant (MCP)

The Ghost Bakery MCP server lets an AI assistant do the whole job from a sentence such as "generate 500 Brazilian customers with a valid CPF as CSV": it looks up the field types, writes a recipe, checks it, shows you sample records, and only then generates, telling you the cost first.

It is a small program that runs on your machine and talks to the Ghost Bakery API with an API key you create. It has no access of its own: everything it can do is what the key allows, and the key's credit limit is a hard cap on what an assistant can spend.

1. Create a key for the assistant

In your account, open API keys and choose the AI agent (MCP) starting point. It selects the scopes an assistant needs, a short validity and a small credit limit. Review them, confirm with your password, and copy the key: it is shown once.

Scope	What the assistant can do with it
`generate`	Check and preview recipes for free, and start generation jobs (spends credits).
`jobs:read`	Follow a job and get its download link.
`catalog:read`	Download reference datasets such as countries and given names (spends credits).
`recipes:read`	List and read your saved recipes.
`recipes:write`	Save and delete recipes. Not in the starting point: add it only if you want the assistant to keep recipes for you.

Use a key just for this. When you no longer want it, revoke it in the same page and it stops working at once.

2. Install the server

Download ghostbakery-mcp for your system from the latest release (Linux and macOS on x86-64 and ARM64, Windows on x86-64). Check it against SHA256SUMS from the same release, rename it to ghostbakery-mcp (ghostbakery-mcp.exe on Windows), make it executable and put it on your PATH. It is a single static program with no dependencies.

terminal

sha256sum --check --ignore-missing SHA256SUMS

The server reads two environment variables:

Variable	Meaning
`GHOSTBAKERY_API_KEY`	The key from step 1. Required.
`GHOSTBAKERY_API_URL`	The API address. Optional; defaults to `https://api.ghostbakery.com`.

3. Add it to your assistant

Claude Code:

terminal

claude mcp add ghostbakery --env GHOSTBAKERY_API_KEY=grd_your_key -- ghostbakery-mcp

Claude Desktop, Cursor and other clients take a JSON entry in their MCP settings:

mcp-settings.json

{
  "mcpServers": {
    "ghostbakery": {
      "command": "ghostbakery-mcp",
      "env": { "GHOSTBAKERY_API_KEY": "grd_your_key" }
    }
  }
}

Restart the assistant and ask it what Ghost Bakery tools it has.

What the assistant can do

Tool	Does	Costs
`ghostbakery_get_reference`	Looks up field types, parameters, formats and limits.	Free
`ghostbakery_validate_recipe`	Checks a recipe and names the exact setting that is wrong.	Free
`ghostbakery_preview_recipe`	Shows 1 to 5 sample records.	Free
`ghostbakery_estimate_cost`	Prices a recipe.	Free
`ghostbakery_generate`	Runs the recipe as a job.	Credits
`ghostbakery_get_job`	Reports a job and, when done, the download link.	Free
`ghostbakery_list_catalog`	Lists the reference datasets you can download.	Free
`ghostbakery_export_catalog`	Downloads up to 1000 rows of a reference dataset.	1 credit per row
`ghostbakery_list_recipes`, `ghostbakery_get_recipe`	Read your saved recipes.	Free
`ghostbakery_save_recipe`, `ghostbakery_delete_recipe`	Keep or remove a saved recipe. Deleting is permanent.	Free

Working examples are also offered to the assistant as resources, so it can start from a recipe that is known to work.

How your credits are protected

A ceiling on every purchase. ghostbakery_generate and ghostbakery_export_catalog require a max_cost. The server prices the request first and sends nothing if it costs more, so nothing is charged.
Nothing is charged twice. Each call carries an idempotency key made from the request, so an assistant that repeats a call, or a network retry, gets the first result back instead of paying again. To run the same recipe again on purpose, the assistant passes a new request_id.
The key is the real limit. The credit limit and expiry you set on the key are enforced by the API, whatever the assistant does. A short validity and a small limit are a sensible default.
Generated data is data. Samples and downloaded rows come back as structured data for the assistant to show you, not as instructions.
The result never enters the conversation. A finished job gives a download link for you to open, not the file.

Troubleshooting

You see	Cause and fix
`GHOSTBAKERY_API_KEY is not set`	The client did not pass the key. Check the `env` entry of the server in its settings.
`401`	The key is wrong, revoked or expired. Create a new one.
`403` and a scope name	The key lacks that scope. Create a key that has it.
`402`	Not enough credits, or the key's credit limit is used up. Add credits, or create a key with a higher limit.
`429`	The key made too many requests. Wait a few seconds; the message says so.

The same operations are available directly over HTTP; see the API reference.