Talk to PisteEarly access
ChatGPT and Claude
Add Piste's MCP server to ChatGPT or Claude to read your ad measurement, start a study and propose a budget change. It needs a connected ad account.
Piste has an MCP server at https://app.usepiste.com/mcp that you can add to ChatGPT or Claude. Once you sign in with your Piste account, the assistant can read your workspace's ad measurement, start a plan study, and propose a campaign budget change that waits for approval in Piste. It can't approve or apply anything, and it reads nothing beyond measurement.
What can ChatGPT and Claude do with Piste?
The server has six tools. Four only read. Two store something in Piste, and neither changes your ad accounts or your store.
| Tool | What it does | Reads or stores |
|---|---|---|
Measurement summary (measurement_summary) | Ad spend and results over a period: blended spend, revenue (Shopify net sales), MER and CAC against the period before, and each channel's spend beside Shopify's last-click revenue and the revenue the platform claims. Also lists alerts and anything that needs reconnecting. | Reads |
Channel performance (channel_performance) | One platform's view, Google or Meta: its spend beside Shopify's last-click revenue and orders, and what the platform claims. | Reads |
List studies (list_studies) | Your most recent measurement studies, newest first, with any budget change each recommends and whether it's approved. Up to 20 at a time. | Reads |
Get a study (get_study) | One study in full: its question, method, what it was computed from, every figure and its recommendations. | Reads |
Start a study (start_study) | Runs a plan study now, as a request in Piste would, and stores it in Piste. It may recommend one budget change, which waits for approval in Piste. | Stores a study |
Propose a budget change (propose_change) | Proposes one campaign's new daily budget for a person to approve in Piste. It applies nothing. | Stores a proposal |
Periods are last week (Monday to Sunday), last month, or dates you give, in your store's time zone and ending before today. The figures are the same ones Piste gives in its own chat and on the Measurement page.
How do I add Piste to ChatGPT or Claude?
Copy the MCP server URL
In Piste, press Connections in the links at the foot of the sidebar. Under Assistants, the "Claude and ChatGPT" card shows the "MCP server URL", https://app.usepiste.com/mcp. Press the copy button beside it.
Add it to your assistant
Add the URL as a custom connector in Claude, or as a connector in ChatGPT. Where that option is, and which plans have it, is up to Claude and ChatGPT: see their own help.
Sign in with your Piste account
When the assistant connects, Piste's sign-in page opens. Sign in with the Piste account you use on the web, and allow access on the consent page. Piste never asks for an API key.
Ask about your ad spend
Ask the assistant something like "How did Meta do last week?". It answers from Piste's measurement, with each number's evidence label.
The assistant then appears on the "Claude and ChatGPT" card as "Connected", with its name and when it was first and last used.
What if no ad account is connected?
The tools measure ad spend, so they need a Google Ads or Meta Ads account connected to Piste, which is in early access. Without one:
| Tool | What it does |
|---|---|
measurement_summary, channel_performance, start_study | Replies "No ad account is connected yet, so there's nothing to measure." |
list_studies, get_study | Still answer, but there are only studies written while an account was connected, if any. |
propose_change | Refuses: it needs a plan study that settled in the last 8 days, and the campaign's ad account still connected. |
Which workspace does the assistant use?
The assistant reads the workspace of the Piste account you signed in with, always. The workspace comes from your sign-in, never from what the assistant sends, and a tool call that adds an argument such as a workspace ID is refused.
An account that has never opened Piste gets: "This Piste account isn't in a workspace yet. Open Piste and sign in once to set it up, then connect this assistant again."
How do proposed budget changes get approved?
propose_change stores the change as a pending recommendation and replies with where to approve it. The change applies nothing until a person approves it in Piste:
- on the study's page in Measurement, with
ApproveorDecline, where the change says "Proposed from an outside assistant"; or - by asking Piste in a chat to apply it.
Only the workspace owner, or the member asking in their own chat, can approve it. Nothing over this connection approves, applies, declines or connects anything.
A proposal must fit the bounds of the latest plan study:
| Rule | Detail |
|---|---|
| Evidence | A plan study that settled in the last 8 days. Run start_study first if there isn't one. |
| Campaign | One whose budget that plan read |
| Budget | A daily budget that can be changed on its own, in the store's currency |
| Size | At most 20% up or down from the live budget, which Piste reads again before storing the proposal |
start_study counts against the workspace's usage like a request in Piste, and is refused when the workspace is over its usage limit.
What do the evidence labels mean?
Every number carries a label for where it came from, best first: Lift test, Mix model, Shopify (Shopify's last click) and Platform-reported. The assistant is told to pass the label on with each number and never to present a Platform-reported number as measured. See Measurement.
What can't the assistant do?
- Talk to the Piste Agent, or see your chats or memory.
- Read orders, products or customers.
- Approve, apply or decline a change, or change anything in an ad account or your store.
- Connect or disconnect anything.
How do I see or revoke an assistant's access?
Each connected assistant is listed on the "Claude and ChatGPT" card on the Connections page, under Assistants, with when it was first and last used. To end its access, press Revoke and confirm. It "can no longer read this workspace's measurement or start studies", and its sign-in can't be renewed. To use it again, connect it again from the assistant and sign in.
The workspace owner sees and can revoke every assistant connected to the workspace.
Related
- Google Ads and Meta: connecting the ad accounts these tools measure.
- Measurement: studies, evidence labels and budget recommendations.
- Weekly plan: the plan study Piste runs every Monday.